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Camara MD, Zhou Y, De Sousa TN, Gil JP, Djimde AA, Lauschke VM. Meta-analysis of the global distribution of clinically relevant CYP2C8 alleles and their inferred functional consequences. Hum Genomics 2024; 18:40. [PMID: 38650020 PMCID: PMC11034136 DOI: 10.1186/s40246-024-00610-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 04/16/2024] [Indexed: 04/25/2024] Open
Abstract
BACKGROUND CYP2C8 is responsible for the metabolism of 5% of clinically prescribed drugs, including antimalarials, anti-cancer and anti-inflammatory drugs. Genetic variability is an important factor that influences CYP2C8 activity and modulates the pharmacokinetics, efficacy and safety of its substrates. RESULTS We profiled the genetic landscape of CYP2C8 variability using data from 96 original studies and data repositories that included a total of 33,185 unrelated participants across 44 countries and 43 ethnic groups. The reduced function allele CYP2C8*2 was most common in West and Central Africa with frequencies of 16-36.9%, whereas it was rare in Europe and Asia (< 2%). In contrast, CYP2C8*3 and CYP2C8*4 were common throughout Europe and the Americas (6.9-19.8% for *3 and 2.3-7.5% for *4), but rare in African and East Asian populations. Importantly, we observe pronounced differences (> 2.3-fold) between neighboring countries and even between geographically overlapping populations. Overall, we found that 20-60% of individuals in Africa and Europe carry at least one CYP2C8 allele associated with reduced metabolism and increased adverse event risk of the anti-malarial amodiaquine. Furthermore, up to 60% of individuals of West African ancestry harbored variants that reduced the clearance of pioglitazone, repaglinide, paclitaxel and ibuprofen. In contrast, reduced function alleles are only found in < 2% of East Asian and 8.3-12.8% of South and West Asian individuals. CONCLUSIONS Combined, the presented analyses mapped the genetic and inferred functional variability of CYP2C8 with high ethnogeographic resolution. These results can serve as a valuable resource for CYP2C8 allele frequencies and distribution estimates of CYP2C8 phenotypes that could help identify populations at risk upon treatment with CYP2C8 substrates. The high variability between ethnic groups incentivizes high-resolution pharmacogenetic profiling to guide precision medicine and maximize its socioeconomic benefits, particularly for understudied populations with distinct genetic profiles.
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Affiliation(s)
- Mahamadou D Camara
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 77, Stockholm, Sweden
- Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, Faculty of Pharmacy, University of Science, Techniques and Technologies, Bamako, Mali
| | - Yitian Zhou
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Taís Nóbrega De Sousa
- Department of Microbiology and Tumor Cell Biology, Karolinska Institutet, Stockholm, Sweden
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Brazil
| | - José P Gil
- Department of Microbiology and Tumor Cell Biology, Karolinska Institutet, Stockholm, Sweden
- Institute of Hygiene and Tropical Medicine, Global Health and Tropical Medicine, Nova University of Lisbon, Lisbon, Portugal
| | - Abdoulaye A Djimde
- Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, Faculty of Pharmacy, University of Science, Techniques and Technologies, Bamako, Mali
| | - Volker M Lauschke
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 77, Stockholm, Sweden.
- Dr Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany.
- University of Tübingen, Tübingen, Germany.
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Marwa KJ, Kapesa A, Kamugisha E, Swedberg G. The Influence of Cytochrome P450 Polymorphisms on Pharmacokinetic Profiles and Treatment Outcomes Among Malaria Patients in Sub-Saharan Africa: A Systematic Review. Pharmgenomics Pers Med 2023; 16:449-461. [PMID: 37223718 PMCID: PMC10202199 DOI: 10.2147/pgpm.s379945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 04/24/2023] [Indexed: 05/25/2023] Open
Abstract
Background Sub-Saharan Africa (SSA) population is genetically diverse and heterogenous thus variability in drug response among individuals is predicted to be high. Cytochrome P450 (CYP450) polymorphisms is a major source of variability in drug response. This systematic review presents the influence of CYP450 single nucleotide polymorphisms (SNPs), particularly CYP3A4*1B, CYP2B6*6 and CYP3A5*3 on antimalarial drug plasma concentrations, efficacy and safety in SSA populations. Methods Searching for relevant studies was done through Google Scholar, Cochrane Central Register of controlled trials (CENTRAL), PubMed, Medline, LILACS, and EMBASE online data bases. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were used. Two independent reviewers extracted data from the studies. Results Thirteen studies reporting the influence of CYP450 SNPs on plasma concentrations, efficacy and safety were included in the final data synthesis. CYP3A4*1B, CYP3A5*5, CYP2B6*6 and CYP2C8*2 did not affect antimalarial drug plasma concentration significantly. There was no difference in treatment outcomes between malaria patients with variant alleles and those with wild type alleles. Conclusion This review reports lack of influence of CYP3A4*1B, CYP3A5*3, CYP2C8*3 and CYP2B6*6 SNPs on PK profiles, efficacy and safety in SSA among P. falciparum malaria patients.
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Affiliation(s)
- Karol J Marwa
- Department of Pharmacology, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Anthony Kapesa
- Department of Community Medicine, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Erasmus Kamugisha
- Department of Biochemistry, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Göte Swedberg
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
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Chan XHS, Chotsiri P, Capel RA, Pike J, Hanboonkunupakarn B, Lee SJ, Hanafiah M, Win YN, Cremer MA, Kiechel J, Ogutu B, Taylor WRJ, Burton RB, Tarning J, White NJ. Cardiovascular concentration-effect relationships of amodiaquine and its metabolite desethylamodiaquine: Clinical and preclinical studies. Br J Clin Pharmacol 2023; 89:1176-1186. [PMID: 36256474 PMCID: PMC7614325 DOI: 10.1111/bcp.15569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/18/2022] [Accepted: 10/10/2022] [Indexed: 11/02/2022] Open
Abstract
AIMS Amodiaquine is a 4-aminoquinoline used extensively for the treatment and prevention of malaria. Orally administered amodiaquine is largely converted to the active metabolite desethylamodiaquine. Amodiaquine can cause bradycardia, hypotension, and electrocardiograph QT interval prolongation, but the relationship of these changes to drug concentrations is not well characterized. METHODS We conducted a secondary analysis of a pharmacokinetic study of the cardiac safety of amodiaquine (10 mg base/kg/day over 3 days) in 54 Kenyan adults (≥18 years) with uncomplicated malaria. Nonlinear mixed effects modelling was used to assess amodiaquine and desethylamodiaquine concentration-effect relationships for vital sign (pulse rate, blood pressure) and electrocardiograph interval (QT, QRS, PR) outcomes. We also measured the spontaneous beating heart rate after cumulative dosing of amodiaquine and desethylamodiaquine in isolated mouse atrial preparations. RESULTS Amodiaquine and desethylamodiaquine caused concentration-dependent mean decreases in pulse rate (1.9 beats/min per 100 nmol/L; 95% confidence interval: 1.5-2.4), supine systolic blood pressure (1.7 mmHg per 100 nmol/L; 1.2-2.1), erect systolic blood pressure (1.5 mmHg per 100 nmol/L; 1.0-2.0) and erect diastolic blood pressure (1.4 mmHg per 100 nmol/L; 1.0-1.7). The mean QT interval prolongation was 1.4 ms per 100 nmol/L irrespective of correction factor after adjustment for residual heart rate dependency. There was no significant effect of drug concentration on postural change in blood pressure or PR and QRS intervals. In mouse atria, the spontaneous beating rate was significantly reduced by amodiaquine (n = 6) and desethylamodiaquine (n = 8) at 3 μmol/L (amodiaquine: 10 ± 2%; desethylamodiaquine: 12 ± 3%) and 10 μmol/L (amodiaquine: 50 ± 7%; desethylamodiaquine: 46 ± 6%) concentrations with no significant difference in potency between the 2 compounds. CONCLUSION Amodiaquine and desethylamodiaquine have concentration-dependent effects on heart rate, blood pressure, and ventricular repolarization.
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Affiliation(s)
- Xin Hui S. Chan
- Mahidol‐Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Palang Chotsiri
- Mahidol‐Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityBangkokThailand
| | | | - James Pike
- Mahidol‐Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityBangkokThailand
| | - Borimas Hanboonkunupakarn
- Mahidol‐Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityBangkokThailand
- Department of Clinical Tropical Medicine, Faculty of Tropical MedicineMahidol UniversityBangkokThailand
| | - Sue J. Lee
- Mahidol‐Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Maryam Hanafiah
- Mahidol‐Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityBangkokThailand
| | - Yan Naung Win
- Mahidol‐Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityBangkokThailand
- Department of Preventive and Social MedicineUniversity of MedicineTaunggyiMyanmar
| | | | | | | | - Walter R. J. Taylor
- Mahidol‐Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUK
| | | | - Joel Tarning
- Mahidol‐Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUK
- WorldWide Antimalarial Research Network, Centre for Tropical Medicine and Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Nicholas J. White
- Mahidol‐Oxford Tropical Medicine Research Unit, Faculty of Tropical MedicineMahidol UniversityBangkokThailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUK
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Taylor SM, Korwa S, Wu A, Green CL, Freedman B, Clapp S, Kirui JK, O’Meara WP, Njuguna FM. Monthly sulfadoxine/pyrimethamine-amodiaquine or dihydroartemisinin-piperaquine as malaria chemoprevention in young Kenyan children with sickle cell anemia: A randomized controlled trial. PLoS Med 2022; 19:e1004104. [PMID: 36215323 PMCID: PMC9591057 DOI: 10.1371/journal.pmed.1004104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 10/24/2022] [Accepted: 08/26/2022] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Children with sickle cell anemia (SCA) in areas of Africa with endemic malaria transmission are commonly prescribed malaria chemoprevention. Chemoprevention regimens vary between countries, and the comparative efficacy of prevention regimens is largely unknown. METHODS AND FINDINGS We enrolled Kenyan children aged 1 to 10 years with homozygous hemoglobin S (HbSS) in a randomized, open-label trial conducted between January 23, 2018, and December 15, 2020, in Homa Bay, Kenya. Children were assigned 1:1:1 to daily Proguanil (the standard of care), monthly sulfadoxine/pyrimethamine-amodiaquine (SP-AQ), or monthly dihydroartemisinin-piperaquine (DP) and followed monthly for 12 months. The primary outcome was the cumulative incidence of clinical malaria at 12 months, and the main secondary outcome was the cumulative incidence of painful events by self-report. Secondary outcomes included other parasitologic, hematologic, and general events. Negative binomial models were used to estimate incidence rate ratios (IRRs) per patient-year (PPY) at risk relative to Proguanil. The primary analytic population was the As-Treated population. A total of 246 children were randomized to daily Proguanil (n = 81), monthly SP-AQ (n = 83), or monthly DP (n = 82). Overall, 53.3% (n = 131) were boys and the mean age was 4.6 ± 2.5 years. The clinical malaria incidence was 0.04 episodes/PPY; relative to the daily Proguanil group, incidence rates were not significantly different in the monthly SP-AQ (IRR: 3.05, 95% confidence interval [CI]: 0.36 to 26.14; p = 0.39) and DP (IRR: 1.36, 95% CI: 0.21 to 8.85; p = 0.90) groups. Among secondary outcomes, relative to the daily Proguanil group, the incidence of painful events was not significantly different in the monthly SP-AQ and DP groups, while monthly DP was associated with a reduced rate of dactylitis (IRR: 0.47; 95% CI: 0.23 to 0.96; p = 0.038). The incidence of Plasmodium falciparum infection relative to daily Proguanil was similar in the monthly SP-AQ group (IRR 0.46; 95% CI: 0.17 to 1.20; p = 0.13) but reduced with monthly DP (IRR 0.21; 95% CI: 0.08 to 0.56; p = 0.002). Serious adverse events were common and distributed between groups, although compared to daily Proguanil (n = 2), more children died receiving monthly SP-AQ (n = 7; hazard ratio [HR] 5.44; 95% CI: 0.92 to 32.11; p = 0.064) but not DP (n = 1; HR 0.61; 95% CI 0.04 to 9.22; p = 0.89), although differences did not reach statistical significance for either SP-AQ or DP. Study limitations include the unexpectedly limited transmission of P. falciparum in the study setting, the high use of hydroxyurea, and the enhanced supportive care for trial participants, which may limit generalizability to higher-transmission settings where routine sickle cell care is more limited. CONCLUSIONS In this study with limited malaria transmission, malaria chemoprevention in Kenyan children with SCA with monthly SP-AQ or DP did not reduce clinical malaria, but DP was associated with reduced dactylitis and P. falciparum parasitization. Pragmatic studies of chemoprevention in higher malaria transmission settings are warranted. TRIAL REGISTRATION clinicaltrials.gov (NCT03178643). Pan-African Clinical Trials Registry: PACTR201707002371165.
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Affiliation(s)
- Steve M. Taylor
- Division of Infectious Diseases, Duke University School of Medicine, Durham, North Carolina, United States of America
- Duke Clinical Research Institute, Durham, North Carolina, United States of America
- Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America
- * E-mail:
| | - Sarah Korwa
- Academic Model Providing Access to Healthcare (AMPATH), Eldoret, Kenya
| | - Angie Wu
- Duke Clinical Research Institute, Durham, North Carolina, United States of America
| | - Cynthia L. Green
- Duke Clinical Research Institute, Durham, North Carolina, United States of America
- Department of Biostatistics and Bioinformatics, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Betsy Freedman
- Division of Infectious Diseases, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Sheila Clapp
- Duke Clinical Research Institute, Durham, North Carolina, United States of America
| | | | - Wendy P. O’Meara
- Division of Infectious Diseases, Duke University School of Medicine, Durham, North Carolina, United States of America
- Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America
| | - Festus M. Njuguna
- Academic Model Providing Access to Healthcare (AMPATH), Eldoret, Kenya
- Department of Child Health and Paediatrics, School of Medicine, College of Health Sciences, Moi University, Eldoret, Kenya
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Nthontho KC, Ndlovu AK, Sharma K, Kasvosve I, Hertz DL, Paganotti GM. Pharmacogenetics of Breast Cancer Treatments: A Sub-Saharan Africa Perspective. Pharmgenomics Pers Med 2022; 15:613-652. [PMID: 35761855 PMCID: PMC9233488 DOI: 10.2147/pgpm.s308531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 05/31/2022] [Indexed: 11/30/2022] Open
Abstract
Breast cancer is the most frequent cause of cancer death in low- and middle-income countries, in particular among sub-Saharan African women, where response to available anticancer treatment therapy is often limited by the recurrent breast tumours and metastasis, ultimately resulting in decreased overall survival rate. This can also be attributed to African genomes that contain more variation than those from other parts of the world. The purpose of this review is to summarize published evidence on pharmacogenetic and pharmacokinetic aspects related to specific available treatments and the known genetic variabilities associated with metabolism and/or transport of breast cancer drugs, and treatment outcomes when possible. The emphasis is on the African genetic variation and focuses on the genes with the highest strength of evidence, with a close look on CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4/5, CYP19A1, UGT1A4, UGT2B7, UGT2B15, SLC22A16, SLC38A7, FcγR, DPYD, ABCB1, and SULT1A1, which are the genes known to play major roles in the metabolism and/or elimination of the respective anti-breast cancer drugs given to the patients. The genetic variability of their metabolism could be associated with different metabolic phenotypes that may cause reduced patients’ adherence because of toxicity or sub-therapeutic doses. Finally, this knowledge enhances possible personalized treatment approaches, with the possibility of improving survival outcomes in patients with breast cancer.
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Affiliation(s)
- Keneuoe Cecilia Nthontho
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana
- Botswana-University of Pennsylvania Partnership, Gaborone, Botswana
| | - Andrew Khulekani Ndlovu
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana
| | | | - Ishmael Kasvosve
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana
| | - Daniel Louis Hertz
- Department of Clinical Pharmacy, University of Michigan College of Pharmacy, Ann Arbor, MI, USA
| | - Giacomo Maria Paganotti
- Botswana-University of Pennsylvania Partnership, Gaborone, Botswana
- Division of Infectious Diseases, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Biomedical Sciences, Faculty of Medicine, University of Botswana, Gaborone, Botswana
- Correspondence: Giacomo Maria Paganotti, Botswana-University of Pennsylvania Partnership, PO Box 45498, Riverwalk Gaborone, Botswana, Tel +267 3555375, Email
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Assessing the Roles of Molecular Markers of Antimalarial Drug Resistance and the Host Pharmacogenetics in Drug-Resistant Malaria. J Trop Med 2022; 2022:3492696. [PMID: 35620049 PMCID: PMC9129956 DOI: 10.1155/2022/3492696] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 04/17/2022] [Accepted: 04/29/2022] [Indexed: 01/11/2023] Open
Abstract
Malaria caused by the Plasmodium parasites is a major public health concern in malaria-endemic regions with P. falciparum causing the most severe form of the disease. The use of antimalarial drugs for the management of the disease proves to be one of the best methods to manage the disease. Unfortunately, P. falciparum has developed resistance to almost all the current in-use antimalarial drugs. Parasite development of resistance is primarily caused by both parasite and host genetic factors. The parasite genetic factors involve undergoing mutation in the drug target sites or increasing the drug target gene copy number to prevent the intended action of the antimalarial drugs. The host pharmacogenetic factors which determine how a particular antimalarial drug is metabolized could result in variations of drug plasma concentration and consequently contribute to variable treatment outcomes and the emergence or propagation of resistant parasites. Since both host and parasite genomes play a role in antimalarial drug action, a key question often asked is, “which of the two strongly drives or controls antimalarial drug resistance?” A major finding in our recent study published in the Malaria Journal indicates that the parasite's genetic factors rather than the host are likely to energize resistance to an antimalarial drug. However, others have reported contrary findings suggesting that the host genetic factors are the force behind resistance to antimalarial drugs. To bring clarity to these observations, there is the need for deciphering the major driving force behind antimalarial drug resistance through optimized strategies aimed at alleviating the phenomenon. In this direction, literature was systematically reviewed to establish the role and importance of each of the two factors aforementioned in the etiology of drug-resistant malaria. Using Internet search engines such as Pubmed and Google, we looked for terms likely to give the desired information which we herein present. We then went ahead to leverage the obtained information to discuss the globally avid aim of combating antimalarial drug resistance.
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Pernaute-Lau L, Camara M, Nóbrega de Sousa T, Morris U, Ferreira MU, Gil JP. An update on pharmacogenetic factors influencing the metabolism and toxicity of artemisinin-based combination therapy in the treatment of malaria. Expert Opin Drug Metab Toxicol 2022; 18:39-59. [PMID: 35285373 DOI: 10.1080/17425255.2022.2049235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Artemisinin-based combination therapies (ACTs) are recommended first-line antimalarials for uncomplicated Plasmodium falciparum malaria. Pharmacokinetic/pharmacodynamic variation associated with ACT drugs and their effect is documented. It is accepted to an extent that inter-individual variation is genetically driven, and should be explored for optimized antimalarial use. AREAS COVERED We provide an update on the pharmacogenetics of ACT antimalarial disposition. Beyond presently used antimalarials, we also refer to information available for the most notable next-generation drugs under development. The bibliographic approach was based on multiple Boolean searches on PubMed covering all recent publications since our previous review. EXPERT OPINION The last 10 years have witnessed an increase in our knowledge of ACT pharmacogenetics, including the first clear examples of its contribution as an exacerbating factor for drug-drug interactions. This knowledge gap is still large and is likely to widen as a new wave of antimalarial drug is looming, with few studies addressing their pharmacogenetics. Clinically useful pharmacogenetic markers are still not available, in particular, from an individual precision medicine perspective. A better understanding of the genetic makeup of target populations can be valuable for aiding decisions on mass drug administration implementation concerning region-specific antimalarial drug and dosage options.
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Affiliation(s)
- Leyre Pernaute-Lau
- Department of Microbiology, Tumor and Cell biology, Karolinska Institutet, Solna, Sweden.,Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, University of Lisbon, Lisbon, 1749-016, Portugal
| | - Mahamadou Camara
- Department of Epidemiology of Parasitic Diseases, Faculty of Pharmacy, Malaria Research and Training Center, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Taís Nóbrega de Sousa
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Brasil
| | - Ulrika Morris
- Department of Microbiology, Tumor and Cell biology, Karolinska Institutet, Solna, Sweden
| | - Marcelo Urbano Ferreira
- Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, University of Lisbon, Lisbon, 1749-016, Portugal.,Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - José Pedro Gil
- Department of Microbiology, Tumor and Cell biology, Karolinska Institutet, Solna, Sweden.,Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, University of Lisbon, Lisbon, 1749-016, Portugal.,Global Health and Tropical Medicine, Institute of Hygiene and Tropical Medicine, Nova University of Lisbon, Portugal
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Ndadza A, Muyambo S, Mntla P, Wonkam A, Chimusa E, Kengne AP, Ntsekhe M, Dandara C. Profiling of warfarin pharmacokinetics-associated genetic variants: Black Africans portray unique genetic markers important for an African specific warfarin pharmacogenetics-dosing algorithm. J Thromb Haemost 2021; 19:2957-2973. [PMID: 34382722 PMCID: PMC9543705 DOI: 10.1111/jth.15494] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 07/28/2021] [Accepted: 08/09/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Warfarin dose variability observed in patients is attributed to variation in genes involved in the warfarin metabolic pathway. Genetic variation in CYP2C9 and VKORC1 has been the traditional focus in evaluating warfarin dose variability, with little focus on other genes. OBJECTIVE We set out to evaluate 27 single nucleotide polymorphisms (SNPs) in the CYP2C cluster loci and 8 genes (VKORC1, ABCB1, CYP2C9, CYP2C19, CYP2C8, CYP1A2, CYP3A4, and CYP3A5) involved in pharmacokinetics of warfarin. PATIENTS/METHODS 503 participants were recruited among black Africans and Mixed Ancestry population groups, from South Africa and Zimbabwe, and a blood sample taken for DNA. Clinical parameters were obtained from patient medical records, and these were correlated with genetic variation. RESULTS Among black Africans, the SNPs CYP2C rs12777823G>A, CYP2C9 c.449G>A (*8), CYP2C9 c.1003C>T (*11) and CYP2C8 c.805A>T (*2) were significantly associated with warfarin maintenance dose. Conversely, CYP2C9 c.430C>T (*2), CYP2C8 c.792C>G (*4) and VKORC1 g.-1639G>A were significantly associated with maintenance dose among the Mixed Ancestry. The presence of CYP2C8*2 and CYP3A5*6 alleles was associated with increased mean warfarin maintenance dose, whereas CYP2C9*8 allele was associated with reduced warfarin maintenance dose. CONCLUSION African populations present with a diversity of variants that are important in predicting pharmacogenetics-based warfarin dosing in addition to those reported in CYP2C9 and VKORC1. It is therefore important, to include African populations in pharmacogenomics studies to be able to identify all possible biomarkers that are potential predictors for drug response.
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Affiliation(s)
- Arinao Ndadza
- Pharmacogenomics and Drug Metabolism Research GroupDivision of Human GeneticsDepartment of Pathology & Institute of Infectious Disease and Molecular Medicine (IDM)Faculty of Health SciencesUniversity of Cape TownCape TownSouth Africa
| | - Sarudzai Muyambo
- Department of Clinical PharmacologyCollege of Health ScienceUniversity of ZimbabweHarareZimbabwe
- Department of Biological SciencesFaculty of Science and EngineeringBindura University of Science and EducationBinduraZimbabwe
| | - Pindile Mntla
- Department of CardiologySefako Makgatho Health Sciences University and Dr. George Mukhari HospitalPretoriaSouth Africa
| | - Ambroise Wonkam
- Pharmacogenomics and Drug Metabolism Research GroupDivision of Human GeneticsDepartment of Pathology & Institute of Infectious Disease and Molecular Medicine (IDM)Faculty of Health SciencesUniversity of Cape TownCape TownSouth Africa
| | - Emile Chimusa
- Pharmacogenomics and Drug Metabolism Research GroupDivision of Human GeneticsDepartment of Pathology & Institute of Infectious Disease and Molecular Medicine (IDM)Faculty of Health SciencesUniversity of Cape TownCape TownSouth Africa
| | - Andre P. Kengne
- Non‐Communicable Diseases Research UnitSouth African Medical Research Council and University of Cape TownCape TownSouth Africa
| | - Mpiko Ntsekhe
- Division of CardiologyDepartment of MedicineFaculty of Health SciencesUniversity of Cape TownCape TownSouth Africa
| | - Collet Dandara
- Pharmacogenomics and Drug Metabolism Research GroupDivision of Human GeneticsDepartment of Pathology & Institute of Infectious Disease and Molecular Medicine (IDM)Faculty of Health SciencesUniversity of Cape TownCape TownSouth Africa
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Chalon S, Chughlay MF, Abla N, Marie Tchouatieu A, Haouala A, Hutter B, Lorch U, Macintyre F. Unanticipated CNS Safety Signal in a Placebo-Controlled, Randomized Trial of Co-Administered Atovaquone-Proguanil and Amodiaquine. Clin Pharmacol Ther 2021; 111:867-877. [PMID: 34453327 PMCID: PMC9291514 DOI: 10.1002/cpt.2404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 07/29/2021] [Indexed: 01/28/2023]
Abstract
Atovaquone‐proguanil (ATV‐PG) plus amodiaquine (AQ) has been considered as a potential replacement for sulfadoxine‐pyrimethamine plus AQ for seasonal malaria chemoprevention in African children. This randomized, double‐blind, placebo‐controlled, parallel group study assessed the safety, tolerability, and pharmacokinetics (PKs) of ATV‐PG plus AQ in healthy adult males and females of Black sub‐Saharan African origin. Participants were randomized to four treatment groups: ATV‐PG/AQ (n = 8), ATV‐PG/placebo (n = 12), AQ/placebo (n = 12), and placebo/placebo (n = 12). Treatments were administered orally once daily for 3 days (days 1–3) at daily doses of ATV‐PQ 1000/400 mg and AQ 612 mg. Co‐administration of ATV‐PG/AQ had no clinically relevant effect on PK parameters for ATV, PG, the PG metabolite cycloguanil, AQ, or the AQ metabolite N‐desethyl‐amodiaquine. Adverse events occurred in 8 of 8 (100%) of participants receiving ATV‐PG/AQ, 11 of 12 (91.7%) receiving ATV‐PG, 11 of 12 (91.7%) receiving AQ, and 3 of 12 (25%) receiving placebo. The safety and tolerability profiles of ATV‐PG and AQ were consistent with previous reports. In the ATV‐PG/AQ group, 2 of 8 participants experienced extrapyramidal adverse effects (EPAEs) on day 3, both psychiatric and physical, which appeared unrelated to drug plasma PKs or cytochrome P450 2C8 phenotype. Although rare cases are reported with AQ administration, the high incidence of EPAE was unexpected in this small study. Owing to the unanticipated increased frequency of EPAE observed, the combination of ATV‐PQ plus AQ is not recommended for further evaluation in prophylaxis of malaria in African children.
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Affiliation(s)
| | | | - Nada Abla
- Medicines for Malaria Venture, Geneva, Switzerland
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10
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Pharmacogene Sequencing of a Gabonese Population with Severe Plasmodium falciparum Malaria Reveals Multiple Novel Variants with Putative Relevance for Antimalarial Treatment. Antimicrob Agents Chemother 2021; 65:e0027521. [PMID: 33875422 DOI: 10.1128/aac.00275-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Malaria remains one of the deadliest diseases in Africa, particularly for children. While successful in reducing morbidity and mortality, antimalarial treatments are also a major cause of adverse drug reactions (ADRs). Host genetic variation in genes involved in drug disposition or toxicity constitutes an important determinant of ADR risk and can prime for parasite drug resistance. Importantly, however, the genetic diversity in Africa is substantial, and thus, genetic profiles in one population cannot be reliably extrapolated to other ethnogeographic groups. Gabon is considered a high-transmission country, with more than 460,000 malaria cases per year. Yet the pharmacogenetic landscape of the Gabonese population or its neighboring countries has not been analyzed. Using targeted sequencing, here, we profiled 21 pharmacogenes with importance for antimalarial treatment in 48 Gabonese pediatric patients with severe Plasmodium falciparum malaria. Overall, we identified 347 genetic variants, of which 18 were novel, and each individual was found to carry 87.3 ± 9.2 (standard deviation [SD]) variants across all analyzed genes. Importantly, 16.7% of these variants were population specific, highlighting the need for high-resolution pharmacogenomic profiling. Between one in three and one in six individuals harbored reduced-activity alleles of CYP2A6, CYP2B6, CYP2D6, and CYP2C8 with important implications for artemisinin, chloroquine, and amodiaquine therapy. Furthermore, one in three patients harbored at least one G6PD-deficient allele, suggesting a considerably increased risk of hemolytic anemia upon exposure to aminoquinolines. Combined, our results reveal the unique genetic landscape of the Gabonese population and pinpoint the genetic basis for interindividual differences in antimalarial drug responses and toxicity.
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11
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Deep and ongoing response of castrate-resistant prostate cancer on very low-dose enzalutamide in an elderly chemotherapy-naïve patient: a case report. Cancer Chemother Pharmacol 2021; 88:165-168. [PMID: 33817752 PMCID: PMC8149336 DOI: 10.1007/s00280-021-04269-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 03/24/2021] [Indexed: 11/21/2022]
Abstract
Background Enzalutamide is an orally administered drug that blocks signaling in the androgen receptor with clinical activity in both chemotherapy–naive and post-chemotherapy patients with castrate-resistant prostate cancer (CRPC). Enzalutamide is generally well-tolerated, but dose reductions are nonetheless needed in case of side effects. Case An 82-year-old patient with chemotherapy–naive metastatic castration-resistant prostate cancer was treated with a very low dose of 40 mg enzalutamide once daily. The trough levels of enzalutamide and the active metabolite N-desmethylenzalutamide were 4.5 mg/L and 3.0 mg/L, respectively. This exposure provided a long-term response without any significant side effects. Conclusion Low doses of enzalutamide may be efficacious, while also reducing the risk of side effects. Furthermore, employing a lower dose would reduce healthcare costs and increase access to enzalutamide. Studies exploring the efficacy of lower enzalutamide doses are warranted.
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12
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Pernaute-Lau L, Morris U, Msellem M, Mårtensson A, Björkman A, Gil JP. Influence of cytochrome P450 (CYP) 2C8 polymorphisms on the efficacy and tolerability of artesunate-amodiaquine treatment of uncomplicated Plasmodium falciparum malaria in Zanzibar. Malar J 2021; 20:90. [PMID: 33588856 PMCID: PMC7885591 DOI: 10.1186/s12936-021-03620-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 02/02/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The anti-malarial drug, amodiaquine, a commonly used, long-acting partner drug in artemisinin-based combination therapy, is metabolized to active desethyl-amodiaquine (DEAQ) by cytochrome P450 2C8 (CYP2C8). The CYP2C8 gene carries several polymorphisms including the more frequent minor alleles, CYP2C8*2 and CYP2C8*3. These minor alleles have been associated with decreased enzymatic activity, slowing the amodiaquine biotransformation towards DEAQ. This study aimed to assess the influence of these CYP2C8 polymorphisms on the efficacy and tolerability of artesunate-amodiaquine (AS-AQ) treatment for uncomplicated Plasmodium falciparum malaria in Zanzibar. METHODS Dried blood spots on filter paper were collected from 618 children enrolled in two randomized clinical trials comparing AS-AQ and artemether-lumefantrine in 2002-2005 in Zanzibar. Study participant were under five years of age with uncomplicated falciparum malaria. Human CYP2C8*2 and CYP2C8*3 genotype frequencies were determined by PCR-restriction fragment length polymorphism. Statistical associations between CYP2C8*2 and/or CYP2C8*3 allele carriers and treatment outcome or occurrence of adverse events were assessed by Fisher's exact test. RESULTS The allele frequencies of CYP2C8*2 and CYP2C8*3 were 17.5 % (95 % CI 15.4-19.7) and 2.7 % (95 % CI 1.8-3.7), respectively. There was no significant difference in the proportion of subjects carrying either CYP2C8*2 or CYP2C8*3 alleles amongst those with re-infections (44.1 %; 95 % CI 33.8-54.8) or those with recrudescent infections (48.3 %; 95 % CI 29.4-67.5), compared to those with an adequate clinical and parasitological response (36.7 %; 95 % CI 30.0-43.9) (P = 0.25 and P = 0.31, respectively). However, patients carrying either CYP2C8*2 or CYP2C8*3 alleles were significantly associated with an increased occurrence of non-serious adverse events, when compared with CYP2C8 *1/*1 wild type homozygotes (44.9 %; 95 % CI 36.1-54.0 vs. 28.1 %; 95 % CI 21.9-35.0, respectively; P = 0.003). CONCLUSIONS CYP2C8 genotypes did not influence treatment efficacy directly, but the tolerability to AS-AQ may be reduced in subjects carrying the CYP2C8*2 and CYP2C8*3 alleles. The importance of this non-negligible association with regard to amodiaquine-based malaria chemotherapy warrants further investigation.
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Affiliation(s)
- Leyre Pernaute-Lau
- Department of Microbiology, Tumor and Cell biology, Karolinska Institutet, Stockholm, Sweden.
- BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016, Lisbon, Portugal.
| | - Ulrika Morris
- Department of Microbiology, Tumor and Cell biology, Karolinska Institutet, Stockholm, Sweden
| | - Mwinyi Msellem
- Training and Research, Mnazi Mmoja Hospital, Zanzibar, Tanzania
| | - Andreas Mårtensson
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
| | - Anders Björkman
- Department of Microbiology, Tumor and Cell biology, Karolinska Institutet, Stockholm, Sweden
| | - Jose Pedro Gil
- Department of Microbiology, Tumor and Cell biology, Karolinska Institutet, Stockholm, Sweden
- BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016, Lisbon, Portugal
- Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade NOVA de Lisboa, 1349-008, Lisbon, Portugal
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13
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Anyorigiya TA, Castel S, Mauff K, Atuguba F, Ogutu B, Oduro A, Dosoo D, Asante KP, Owusu-Agyei S, Dodoo A, Hodgson A, Binka F, Workman LJ, Allen EN, Denti P, Wiesner L, Barnes KI. Pharmacokinetic profile of amodiaquine and its active metabolite desethylamodiaquine in Ghanaian patients with uncomplicated falciparum malaria. Malar J 2021; 20:18. [PMID: 33407454 PMCID: PMC7788723 DOI: 10.1186/s12936-020-03553-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 12/15/2020] [Indexed: 11/26/2022] Open
Abstract
Background Accurate measurement of anti-malarial drug concentrations in therapeutic efficacy studies is essential to distinguish between inadequate drug exposure and anti-malarial drug resistance, and to inform optimal anti-malarial dosing in key target population groups. Methods A sensitive and selective LC–MS/MS method was developed and validated for the simultaneous determination of amodiaquine and its active metabolite, desethylamodiaquine, and used to describe their pharmacokinetic parameters in Ghanaian patients with uncomplicated falciparum malaria treated with the fixed-dose combination, artesunate-amodiaquine. Results The day-28 genotype-adjusted adequate clinical and parasitological response rate in 308 patients studied was > 97% by both intention-to-treat and per-protocol analysis. After excluding 64 patients with quantifiable amodiaquine concentrations pre-treatment and 17 with too few quantifiable concentrations, the pharmacokinetic analysis included 227 patients (9 infants, 127 aged 1–4 years, 91 aged ≥ 5 years). Increased median day-3 amodiaquine concentrations were associated with a lower risk of treatment failure [HR 0.87 (95% CI 0.78–0.98), p = 0.021]. Amodiaquine exposure (median AUC0-∞) was significantly higher in infants (4201 ng h/mL) and children aged 1–5 years (1994 ng h/mL) compared to older children and adults (875 ng h/mL, p = 0.001), even though infants received a lower mg/kg amodiaquine dose (median 25.3 versus 33.8 mg/kg in older patients). Desethylamodiaquine AUC0-∞ was not significantly associated with age. No significant safety concerns were identified. Conclusions Efficacy of artesunate-amodiaquine at currently recommended dosage regimens was high across all age groups. Reassuringly, amodiaquine and desethylamodiaquine exposure was not reduced in underweight-for-age young children or those with high parasitaemia, two of the most vulnerable target populations. A larger pharmacokinetic study with close monitoring of safety, including full blood counts and liver function tests, is needed to confirm the higher amodiaquine exposure in infants, understand any safety implications and assess whether dose optimization in this vulnerable, understudied population is needed.
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Affiliation(s)
- Thomas A Anyorigiya
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa.,UCT/MRC Collaborating Centre for Optimising Antimalarial Therapy (CCOAT), University of Cape Town, Cape Town, South Africa.,Navrongo Health Research Centre, Navrongo, Ghana
| | - Sandra Castel
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Katya Mauff
- Department of Statistical Sciences, University of Cape Town, Cape Town, South Africa
| | - Frank Atuguba
- Navrongo Health Research Centre, Navrongo, Ghana.,Dodowa Health Research Centre, Dodowa, Ghana
| | - Bernhards Ogutu
- Centre for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya
| | | | - David Dosoo
- Kintampo Health Research Centre, Kintampo, Ghana
| | | | - Seth Owusu-Agyei
- University for Health and Allied Sciences, Ho, Volta Region, Ghana
| | | | - Abraham Hodgson
- Navrongo Health Research Centre, Navrongo, Ghana.,Research and Development Division, Ghana Health Service, Accra, Ghana
| | - Fred Binka
- University for Health and Allied Sciences, Ho, Volta Region, Ghana
| | - Lesley J Workman
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa.,UCT/MRC Collaborating Centre for Optimising Antimalarial Therapy (CCOAT), University of Cape Town, Cape Town, South Africa
| | - Elizabeth N Allen
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa.,UCT/MRC Collaborating Centre for Optimising Antimalarial Therapy (CCOAT), University of Cape Town, Cape Town, South Africa
| | - Paolo Denti
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa.,UCT/MRC Collaborating Centre for Optimising Antimalarial Therapy (CCOAT), University of Cape Town, Cape Town, South Africa
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa.,UCT/MRC Collaborating Centre for Optimising Antimalarial Therapy (CCOAT), University of Cape Town, Cape Town, South Africa
| | - Karen I Barnes
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa. .,UCT/MRC Collaborating Centre for Optimising Antimalarial Therapy (CCOAT), University of Cape Town, Cape Town, South Africa.
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14
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Pallerla SR, Elion Assiana DO, Linh LTK, Cho FN, Meyer CG, Fagbemi KA, Adegnika AA, Beng VP, Achidi EA, Kahunu GM, Bates M, Grobusch MP, Kremsner PG, Ntoumi F, Velavan TP. Pharmacogenetic considerations in the treatment of co-infections with HIV/AIDS, tuberculosis and malaria in Congolese populations of Central Africa. Int J Infect Dis 2020; 104:207-213. [PMID: 33310105 DOI: 10.1016/j.ijid.2020.12.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 11/30/2020] [Accepted: 12/04/2020] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND HIV-infection, tuberculosis and malaria are the big three communicable diseases that plague sub-Saharan Africa. If these diseases occur as co-morbidities they require polypharmacy, which may lead to severe drug-drug-gene interactions and variation in adverse drug reactions, but also in treatment outcomes. Polymorphisms in genes encoding drug-metabolizing enzymes are the major cause of these variations, but such polymorphisms may support the prediction of drug efficacy and toxicity. There is little information on allele frequencies of pharmacogenetic variants of enzymes involved in the metabolism of drugs used to treat HIV-infection, TB and malaria in the Republic of Congo (ROC). The aim of this study was therefore to investigate the occurrence and allele frequencies of 32 pharmacogenetic variants localized in absorption distribution, metabolism and excretion (ADME) and non-ADME genes and to compare the frequencies with population data of Africans and non-Africans derived from the 1000 Genomes Project. RESULTS We found significant differences in the allele frequencies of many of the variants when comparing the findings from ROC with those of non-African populations. On the other hand, only a few variants showed significant differences in their allele frequencies when comparing ROC with other African populations. In addition, considerable differences in the allele frequencies of the pharmacogenetic variants among the African populations were observed. CONCLUSIONS The findings contribute to the understanding of pharmacogenetic variants involved in the metabolism of drugs used to treat HIV-infection, TB and malaria in ROC and their diversity in different populations. Such knowledge helps to predict drug efficacy, toxicity and ADRs and to inform individual and population-based decisions.
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Affiliation(s)
- Srinivas Reddy Pallerla
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstrasse 27, 72074 Tübingen, Germany; Vietnamese-German Center for Medical Research, VG-CARE, Hanoi, Viet Nam
| | - Darrel Ornelle Elion Assiana
- Fondation Congolaise pour la Recherche Médicale (FCRM), Brazzaville, Congo; Faculty of Sciences and Technology, University Marien Ngouabi, Brazzaville, Congo
| | - Le Thi Kieu Linh
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstrasse 27, 72074 Tübingen, Germany; Vietnamese-German Center for Medical Research, VG-CARE, Hanoi, Viet Nam
| | - Frederick Nchang Cho
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstrasse 27, 72074 Tübingen, Germany; Department of Biochemistry and Molecular Biology, Faculty of Science, Laboratory of Infectious Diseases, Faculty of Health Sciences, University of Buea, Buea, Cameroon
| | - Christian G Meyer
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstrasse 27, 72074 Tübingen, Germany; Vietnamese-German Center for Medical Research, VG-CARE, Hanoi, Viet Nam; Faculty of Medicine, Duy Tan University, Da Nang, Viet Nam
| | - Kaossarath Adédjokè Fagbemi
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstrasse 27, 72074 Tübingen, Germany; Department of Biomedical Sciences, Laboratory of Cytogenetics and Medical Genetics, Faculty of Health Sciences, University of Abomey-Calavi, Benin
| | - Ayola Akim Adegnika
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstrasse 27, 72074 Tübingen, Germany; Centre de Recherches Medicales de Lambarene, Lambarene, Gabon
| | - Véronique Penlap Beng
- Department of Biochemistry, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon
| | - Eric A Achidi
- Department of Biochemistry and Molecular Biology, Faculty of Science, Laboratory of Infectious Diseases, Faculty of Health Sciences, University of Buea, Buea, Cameroon
| | - Gauthier Mesia Kahunu
- Unit of Clinical Pharmacology and Pharmacovigilance, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Mathew Bates
- School of Life Sciences, University of Lincoln, Lincoln, United Kingdom
| | - Martin P Grobusch
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstrasse 27, 72074 Tübingen, Germany; Centre de Recherches Medicales de Lambarene, Lambarene, Gabon; Center for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Amsterdam University Medical Centers, University of Amsterdam, The Netherlands
| | - Peter G Kremsner
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstrasse 27, 72074 Tübingen, Germany; Centre de Recherches Medicales de Lambarene, Lambarene, Gabon
| | - Francine Ntoumi
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstrasse 27, 72074 Tübingen, Germany; Fondation Congolaise pour la Recherche Médicale (FCRM), Brazzaville, Congo; Faculty of Sciences and Technology, University Marien Ngouabi, Brazzaville, Congo
| | - Thirumalaisamy P Velavan
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstrasse 27, 72074 Tübingen, Germany; Vietnamese-German Center for Medical Research, VG-CARE, Hanoi, Viet Nam; Fondation Congolaise pour la Recherche Médicale (FCRM), Brazzaville, Congo; Faculty of Medicine, Duy Tan University, Da Nang, Viet Nam.
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15
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Habtemikael L, Russom M, Bahta I, Mihreteab S, Berhane A, Mårtensson A, Gil JP. Prevalence of CYP2C8*2 and *3 among Eritreans and its Potential Impact on Artesunate/Amodiaquine Treatment. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2020; 13:571-575. [PMID: 33209048 PMCID: PMC7669516 DOI: 10.2147/pgpm.s276215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 10/16/2020] [Indexed: 12/23/2022]
Abstract
Background In Eritrea, artesunate–amodiaquine is the first-line treatment against uncomplicated malaria. Amodiaquine, which is mainly bio-transformed by CYP2C8, is known to be associated with adverse events of different severity. Extrapyramidal events are among the less common but have been reported with non-negligible frequency in Eritrea. This study was conducted to investigate the allele frequencies of CYP2C8*2 and *3, both associated with decreased amodiaquine metabolism, among the Eritrean population. Methods During September–November 2018, dried blood samples from 380 participants and 17 patients who previously had experienced extrapyramidal symptoms following treatment of artesunate–amodiaquine were collected and PCR-RFLP genotyped for CYP2C8*2 and *3. Results The allele frequencies of CYP2C8*2 and *3 were determined as 5.9% (95% CI: 4.4–7.8) and 4.6% (95% CI: 3.2–6.3), respectively. Four out of the 17 patients with extrapyramidal reactions showed to be carriers of the alleles. Conclusion CYP2C8*2 and *3 frequencies among Eritreans were found to be intermediate between the documented for Caucasian and African populations. These findings, along with the alleles not being decisive for the occurrence of extrapyramidal events, might be of importance regarding the amodiaquine-containing malaria treatment in Eritrea. Furthermore, it suggests a significant proportion of slow amodiaquine metabolizers in the Sahel region, information of potential interest in the context of amodiaquine-involving seasonal malaria chemoprevention.
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Affiliation(s)
- Lidia Habtemikael
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
| | - Mulugeta Russom
- National Medicines and Food Administration, Ministry of Health, Asmara, Eritrea
| | - Iyassu Bahta
- National Medicines and Food Administration, Ministry of Health, Asmara, Eritrea
| | - Selam Mihreteab
- National Malaria Control Programme, Ministry of Health, Asmara, Eritrea
| | - Araia Berhane
- Communicable Diseases Control Division, Ministry of Health, Asmara, Eritrea
| | - Andreas Mårtensson
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
| | - Jose Pedro Gil
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden.,Department of Microbiology and Tumour Cell Biology, Karolinska Institute, Stockholm, Sweden.,Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
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16
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Hodoameda P, Duah-Quashie NO, Hagan CO, Matrevi S, Abuaku B, Koram K, Quashie NB. Plasmodium falciparum genetic factors rather than host factors are likely to drive resistance to ACT in Ghana. Malar J 2020; 19:255. [PMID: 32669113 PMCID: PMC7362516 DOI: 10.1186/s12936-020-03320-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 07/04/2020] [Indexed: 12/13/2022] Open
Abstract
Background Artemisinin-based combination therapy (ACT) partner drugs, currently used in Ghana are lumefantrine, amodiaquine and piperaquine. Plasmodium falciparum isolates with reduced susceptibility to these partner drugs may affect treatment outcome. Mutations in pfmdr1 gene is linked to reduced parasite susceptibility to amodiaquine and lumefantrine. In addition, the potency of the partner drugs in vivo depends on the metabolism by the cytochrome P450 (CYP) enzyme in the host. Mutations in the CYP2C8 and CYP3A4 genes are linked to reduced metabolism of amodiaquine and lumefantrine in vitro, respectively. This study investigated the host and parasite genetic factors affecting the susceptibility of the malaria parasite to ACT partner drugs. Methods Archived samples from 240 patients age ≤ 9 years participating in anti-malarial drug resistance survey in Ghana, and given artemether with lumefantrine (AL) or artesunate with amodiaquine (AA), were selected and analysed. Polymerase chain reaction (PCR) followed by Sanger sequencing was used to determine the polymorphisms in CYP2C8, CYP3A4 and pfmdr1 genes. Results For CYP3A4, all had wild type alleles, suggesting that the hosts are good metabolizers of lumefantrine. For CYP2C8 60% had wild type alleles, 35% heterozygous and 5% homozygous recessive alleles suggesting efficient metabolism of amodiaquine by the hosts. For pfmdr1 gene, at codon 86, 95% were wild type (N86) and 5% mutant (Y86). For codon 184, 36% were wild type (Y184) and 64% mutant (F184) while for codons 1034, 1042 and 1246, 100% (all) were wild type. The high prevalence of N86-F184-D1246 haplotype (NFD) suggest presence of parasites with reduced susceptibility to lumefantrine and not amodiaquine. Delayed clearance was observed in individuals with mutations in the pfmdr1 gene and not cytochrome 450 gene. Both synonymous and non-synonymous mutations were observed in the pfmdr1 at low prevalence. Conclusion The outcome of this study indicates that the parasite's genetic factors rather than the host’s are likely to drive resistance to ACT in Ghana.
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Affiliation(s)
- Peter Hodoameda
- West African Center for Cell Biology of Infectious Pathogens, University of Ghana, P. O. Box LG54, Legon, Ghana
| | - Nancy Odurowah Duah-Quashie
- Epidemiology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P. O. Box LG581, Legon, Ghana
| | | | - Sena Matrevi
- Epidemiology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P. O. Box LG581, Legon, Ghana
| | - Benjamin Abuaku
- Epidemiology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P. O. Box LG581, Legon, Ghana
| | - Kwadwo Koram
- Epidemiology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P. O. Box LG581, Legon, Ghana
| | - Neils Ben Quashie
- West African Center for Cell Biology of Infectious Pathogens, University of Ghana, P. O. Box LG54, Legon, Ghana. .,Epidemiology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P. O. Box LG581, Legon, Ghana. .,Centre for Tropical Clinical Pharmacology and Therapeutics, University of Ghana Medical School, P. O. Box GP4236, Accra, Ghana.
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17
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Somé FA, Bazié T, Ehrlich HY, Goodwin J, Lehane A, Neya C, Zachari K, Wade M, Ouattara JM, Foy BD, Dabiré RK, Parikh S, Ouédraogo JB. Investigating selected host and parasite factors potentially impacting upon seasonal malaria chemoprevention in Bama, Burkina Faso. Malar J 2020; 19:238. [PMID: 32631416 PMCID: PMC7339464 DOI: 10.1186/s12936-020-03311-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/26/2020] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Since 2014, seasonal malaria chemoprevention (SMC) with amodiaquine-sulfadoxine-pyrimethamine (AQ-SP) has been implemented on a large scale during the high malaria transmission season in Burkina Faso. This paper reports the prevalence of microscopic and submicroscopic malaria infection at the outset and after the first round of SMC in children under 5 years old in Bama, Burkina Faso, as well as host and parasite factors involved in mediating the efficacy and tolerability of SMC. METHODS Two sequential cross-sectional surveys were conducted in late July and August 2017 during the first month of SMC in a rural area in southwest Burkina Faso. Blood smears and dried blood spots were collected from 106 to 93 children under five, respectively, at the start of SMC and again 3 weeks later. Malaria infection was detected by microscopy and by PCR from dried blood spots. For all children, day 7 plasma concentrations of desethylamodiaquine (DEAQ) were measured and CYP2C8 genetic variants influencing AQ metabolism were genotyped. Samples were additionally genotyped for pfcrt K76T and pfmdr1 N86Y, molecular markers associated with reduced amodiaquine susceptibility. RESULTS 2.8% (3/106) of children were positive for Plasmodium falciparum infection by microscopy and 13.2% (14/106) by nested PCR within 2 days of SMC administration. Three weeks after SMC administration, in the same households, 4.3% (4/93) of samples were positive by microscopy and 14.0% (13/93) by PCR (p = 0.0007). CYP2C8*2, associated with impaired amodiaquine metabolism, was common with an allelic frequency of 17.1% (95% CI 10.0-24.2). Day 7 concentration of DEAQ ranged from 0.48 to 362.80 ng/mL with a median concentration of 56.34 ng/mL. Pfmdr1 N86 predominated at both time points, whilst a non-significant trend towards a higher prevalence of pfcrt 76T was seen at week 3. CONCLUSION This study showed a moderate prevalence of low-level malaria parasitaemia in children 3 weeks following SMC during the first month of administration. Day 7 concentrations of the active DEAQ metabolite varied widely, likely reflecting variability in adherence and possibly metabolism. These findings highlight factors that may contribute to the effectiveness of SMC in children in a high transmission setting.
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Affiliation(s)
- Fabrice A Somé
- Institut de Recherche en Sciences de la Santé, Direction Régionale de l'Ouest, 399 Avenue de la Liberté, 01, BP 545, Bobo-Dioulasso 01, Burkina Faso.
| | - Thomas Bazié
- Institut de Recherche en Sciences de la Santé, Direction Régionale de l'Ouest, 399 Avenue de la Liberté, 01, BP 545, Bobo-Dioulasso 01, Burkina Faso
| | - Hanna Y Ehrlich
- Yale Schools of Public Health and Medicine, Laboratory of Epidemiology and Public Health, 60 College Street, Room 724, New Haven, CT, 06520, USA
| | - Justin Goodwin
- Yale Schools of Public Health and Medicine, Laboratory of Epidemiology and Public Health, 60 College Street, Room 724, New Haven, CT, 06520, USA
| | - Aine Lehane
- Yale Schools of Public Health and Medicine, Laboratory of Epidemiology and Public Health, 60 College Street, Room 724, New Haven, CT, 06520, USA
| | - Catherine Neya
- Institut de Recherche en Sciences de la Santé, Direction Régionale de l'Ouest, 399 Avenue de la Liberté, 01, BP 545, Bobo-Dioulasso 01, Burkina Faso
| | - Kabré Zachari
- Institut de Recherche en Sciences de la Santé, Direction Régionale de l'Ouest, 399 Avenue de la Liberté, 01, BP 545, Bobo-Dioulasso 01, Burkina Faso
| | - Martina Wade
- Yale Schools of Public Health and Medicine, Laboratory of Epidemiology and Public Health, 60 College Street, Room 724, New Haven, CT, 06520, USA
| | - Jean-Marie Ouattara
- Institut de Recherche en Sciences de la Santé, Direction Régionale de l'Ouest, 399 Avenue de la Liberté, 01, BP 545, Bobo-Dioulasso 01, Burkina Faso
| | - Brian D Foy
- Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Roch K Dabiré
- Institut de Recherche en Sciences de la Santé, Direction Régionale de l'Ouest, 399 Avenue de la Liberté, 01, BP 545, Bobo-Dioulasso 01, Burkina Faso
| | - Sunil Parikh
- Yale Schools of Public Health and Medicine, Laboratory of Epidemiology and Public Health, 60 College Street, Room 724, New Haven, CT, 06520, USA
| | - Jean-Bosco Ouédraogo
- Institut de Recherche en Sciences de la Santé, Direction Régionale de l'Ouest, 399 Avenue de la Liberté, 01, BP 545, Bobo-Dioulasso 01, Burkina Faso
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Influence of CYP2C8, CYP3A4, and CYP3A5 Host Genotypes on Early Recurrence of Plasmodium vivax. Antimicrob Agents Chemother 2020; 64:AAC.02125-19. [PMID: 32366712 DOI: 10.1128/aac.02125-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 04/25/2020] [Indexed: 11/20/2022] Open
Abstract
Cytochrome P450 (CYP) enzymes are involved in the biotransformation of chloroquine (CQ), but the role of the different profiles of metabolism of this drug in relation to Plasmodium vivax recurrences has not been properly investigated. To investigate the influence of the CYP genotypes associated with CQ metabolism on the rates of P. vivax early recurrences, a case-control study was carried out. The cases included patients presenting with an early recurrence (CQ-recurrent individuals), defined as a recurrence during the first 28 days after initial infection and plasma concentrations of CQ plus desethylchloroquine (DCQ; the major CQ metabolite) higher than 100 ng/ml. A control group with no parasite recurrence over the follow-up (the CQ-responsive group) was also included. CQ and DCQ plasma levels were measured on day 28. CQ-metabolizing CYP (CYP2C8, CYP3A4, and CYP3A5) genotypes were determined by real-time PCR. An ex vivo study was conducted to verify the efficacy of CQ and DCQ against P. vivax isolates. The frequency of alleles associated with normal and slow metabolism was similar between the cases and the controls for the CYP2C8 (odds ratio [OR] = 1.45, 95% confidence interval [CI] = 0.51 to 4.14, P = 0.570), CYP3A4 (OR = 2.38, 95% CI = 0.92 to 6.19, P = 0.105), and CYP3A5 (OR = 4.17, 95% CI = 0.79 to 22.04, P = 1.038) genes. DCQ levels were higher than CQ levels, regardless of the genotype. Regarding the DCQ/CQ ratio, there was no difference between groups or between those patients who had a normal genotype and those patients who had a mutant genotype. DCQ and CQ showed similar efficacy ex vivo CYP genotypes had no influence on early recurrence rates. The similar efficacy of CQ and DCQ ex vivo could explain the absence of therapeutic failure, despite the presence of alleles associated with slow metabolism.
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19
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Banerjee BD, Kumar R, Thamineni KL, Shah H, Thakur GK, Sharma T. Effect of Environmental Exposure and Pharmacogenomics on Drug Metabolism. Curr Drug Metab 2020; 20:1103-1113. [PMID: 31933442 DOI: 10.2174/1389200221666200110153304] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 11/02/2019] [Accepted: 01/03/2020] [Indexed: 12/17/2022]
Abstract
BACKGROUND Pesticides are major xenobiotic compounds and environmental pollutants, which are able to alter drug-metabolizing enzyme as well as pharmacokinetics of drugs. Subsequent to the release of the human genome project, genetic variations (polymorphism) become an integral part of drug development due to their influence on disease susceptibility/ progression of the disease and their impact on drug absorption, distribution, metabolism of active metabolites and finally excretion of the drug. Genetic polymorphisms crucially regulate pharmacokinetics and pharmacodynamics of drugs under the influence of physiological condition, lifestyle, as well as pathological conditions collectively. OBJECTIVE To review all the evidence concerning the effect of environmental exposure on drug metabolism with reference to pharmacogenomics. METHODS Scientific data search and review of basic, epidemiological, pharmacogenomics and pharmacokinetics studies were undertaken to evaluate the influence of environmental contaminants on drug metabolism. RESULTS Various environmental contaminants like pesticides effectively alter drug metabolism at various levels under the influence of pharmacogenomics, which interferes with pharmacokinetics of drug metabolism. Genetic polymorphism of phase I and phase II xenobiotic-metabolizing enzymes remarkably alters disease susceptibility as well as the progression of disease under the influence of various environmental contaminants at various levels. CONCLUSION Individual specific drug response may be attributed to a large variety of factors alone or in combination ranging from genetic variations (SNP, insertion, deletion, duplication etc.) to physiological setting (gender, age, body size, and ethnicity), environmental or lifestyle factors (radiation exposure, smoking, alcohol, nutrition, exposure to toxins, etc.); and pathological conditions (obesity, diabetes, liver and renal function).
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Affiliation(s)
- Basu Dev Banerjee
- Environmental Biochemistry and Molecular Biology Laboratory, Department of Biochemistry, University College of Medical Sciences and GTB Hospital (University of Delhi), Dilshad Garden, Delhi-110095, India
| | - Ranjeet Kumar
- Environmental Biochemistry and Molecular Biology Laboratory, Department of Biochemistry, University College of Medical Sciences and GTB Hospital (University of Delhi), Dilshad Garden, Delhi-110095, India
| | - Krishna Latha Thamineni
- Environmental Biochemistry and Molecular Biology Laboratory, Department of Biochemistry, University College of Medical Sciences and GTB Hospital (University of Delhi), Dilshad Garden, Delhi-110095, India
| | - Harendra Shah
- Environmental Biochemistry and Molecular Biology Laboratory, Department of Biochemistry, University College of Medical Sciences and GTB Hospital (University of Delhi), Dilshad Garden, Delhi-110095, India
| | - Gaurav Kumar Thakur
- Environmental Biochemistry and Molecular Biology Laboratory, Department of Biochemistry, University College of Medical Sciences and GTB Hospital (University of Delhi), Dilshad Garden, Delhi-110095, India
| | - Tusha Sharma
- Environmental Biochemistry and Molecular Biology Laboratory, Department of Biochemistry, University College of Medical Sciences and GTB Hospital (University of Delhi), Dilshad Garden, Delhi-110095, India
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20
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Ding J, Coldiron ME, Assao B, Guindo O, Blessborn D, Winterberg M, Grais RF, Koscalova A, Langendorf C, Tarning J. Adherence and Population Pharmacokinetic Properties of Amodiaquine When Used for Seasonal Malaria Chemoprevention in African Children. Clin Pharmacol Ther 2019; 107:1179-1188. [PMID: 31652336 PMCID: PMC7232861 DOI: 10.1002/cpt.1707] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 08/29/2019] [Indexed: 01/23/2023]
Abstract
Poor adherence to seasonal malaria chemoprevention (SMC) might affect the protective effectiveness of SMC. Here, we evaluated the population pharmacokinetic properties of amodiaquine and its active metabolite, desethylamodiaquine, in children receiving SMC under directly observed ideal conditions (n = 136), and the adherence of SMC at an implementation phase in children participating in a case‐control study to evaluate SMC effectiveness (n = 869). Amodiaquine and desethylamodiaquine concentration‐time profiles were described simultaneously by two‐compartment and three‐compartment disposition models, respectively. The developed methodology to evaluate adherence showed a sensitivity of 65–71% when the first dose of SMC was directly observed and 71–73% when no doses were observed in a routine programmatic setting. Adherence simulations and measured desethylamodiaquine concentrations in the case‐control children showed complete adherence (all doses taken) in < 20% of children. This result suggests that more efforts are needed urgently to improve the adherence to SMC among children in this area.
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Affiliation(s)
- Junjie Ding
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.,The WorldWide Antimalarial Resistance Network, Oxford, UK.,Children's Hospital of Fudan University, Shanghai, China
| | | | | | | | - Daniel Blessborn
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.,Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Markus Winterberg
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.,Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | | | | | - Joel Tarning
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.,The WorldWide Antimalarial Resistance Network, Oxford, UK.,Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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Bolaji OO, Adehin A, Adeagbo BA. Pharmacogenomics in the Nigerian population: the past, the present and the future. Pharmacogenomics 2019; 20:915-926. [DOI: 10.2217/pgs-2019-0046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The Nigerian population exhibits huge ethnic and genetic diversity, typical of African populations, which can be harnessed for improved drug-response and disease management. Existing data on genes relevant to drug response, so far generated for the population, indeed confirm the prevalence of some clinically significant pharmacogenes. These reports detail prevailing genetic alleles and metabolic phenotypes of vital drug metabolizing monooxygenases, transferases and drug transporters. While the utilization of existing pharmacogenomic data for healthcare delivery remains unpopular, several past and on-going studies suggest that a future shift toward genotype-stratified dosing of drugs and disease management in the population is imminent. This review discusses the present state of pharmacogenomics in Nigeria and the potential benefits of sustained research in this field for the population.
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Affiliation(s)
- Oluseye O Bolaji
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Ayorinde Adehin
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria
- Institute of Biomedical & Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, PR China
| | - Babatunde A Adeagbo
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria
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22
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Distribution of the cytochrome P450 CYP2C8*2 allele in Brazzaville, Republic of Congo. Int J Infect Dis 2019; 85:49-53. [DOI: 10.1016/j.ijid.2019.04.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 04/26/2019] [Accepted: 04/30/2019] [Indexed: 01/03/2023] Open
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23
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Pharmacogenomics in Papua New Guineans: unique profiles and implications for enhancing drug efficacy while improving drug safety. Pharmacogenet Genomics 2019; 28:153-164. [PMID: 29768302 DOI: 10.1097/fpc.0000000000000335] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Papua New Guinea (PNG) can be roughly divided into highland, coastal and island peoples with significant mitochondrial DNA differentiation reflecting early and recent distinct migrations from Africa and East Asia, respectively. Infectious diseases such as tuberculosis, malaria and HIV severely impact on the health of its peoples for which drug therapy is the major treatment and pharmacogenetics has clinical relevance for many of these drugs. Although there is generally little information about known single nucleotide polymorphisms in the population, in some instances, their frequencies have been shown to be higher than anywhere worldwide. For example, CYP2B6*6 is over 50%, and CYP2C19*2 and *3 are over 40 and 25%, respectively. Conversely, CYP2A6*9, 2B6*2, *3, *4 and *18, and 2C8*3 appear to be much lower than in Whites. CYP2D6 known variants are unclear, and for phase II enzymes, only UGT2B7 and UGT1A9 data are available, with variant frequencies either slightly lower than or similar to Whites. Although almost all PNG people tested are rapid acetylators, but which variant(s) define this phenotype is not known. For HLA-B*13:01, HLA-B*35:05 and HLA-C*04:01, the frequencies show some regioselectivity, but the clinical implications with respect to adverse drug reactions are not known. There are minimal phenotype data for the CYPs and nothing is known about drug transporter or receptor genetics. Determination of genetic variants that are rare in Whites or Asians but common in PNG people is a topic of both scientific and clinical importance, and further research needs to be carried out. Optimizing the safety and efficacy of infectious disease drug therapy through pharmacogenetic studies that have translation potential is a priority.
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24
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Albassam AA, Frye RF. Effect of pterostilbene on in vitro drug metabolizing enzyme activity. Saudi Pharm J 2019; 27:406-412. [PMID: 30976185 PMCID: PMC6438784 DOI: 10.1016/j.jsps.2019.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 01/05/2019] [Indexed: 01/14/2023] Open
Abstract
Pterostilbene is a natural polyphenol compound found in small berries that is related to resveratrol, but has better bioavailability and a longer half-life. The purpose of this study was to assess the potential inhibitory effect of pterostilbene on in vitro drug metabolism. The effect of pterostilbene on cytochrome P450 (CYP) and UDP-glucuronosyltransferase (UGT) enzyme activities were studied using the enzyme-selective substrates amodiaquine (CYP2C8), midazolam (CYP3A4), estradiol (UGT1A1), serotonin (UGT1A6) and mycophenolic acid (UGT1A8/9/10). The IC50 value was used to express the strength of inhibition. Further, a volume per dose index (VDI) was used to estimate the potential for in vivo interactions. Pterostilbene significantly inhibited CYP2C8 and UGT1A6 activities. The IC50 (mean ± SE) values for CYP2C8 and UGT1A6 inhibition were 3.0 ± 0.4 µM and 15.1 ± 2.8 µM, respectively; the VDI exceeded the predefined threshold of 5 L/dose for both CYP2C8 and UGT1A6, suggesting a potential for interaction in vivo. Pterostilbene did not inhibit the metabolism of the other enzyme-selective substrates. The results of this study indicate that pterostilbene inhibits CYP2C8 and UTG1A6 activity in vitro and may inhibit metabolism by these enzymes in vivo. Clinical studies are warranted to evaluate the in vivo relevance of these interactions.
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Key Words
- Amodiaquine
- CYP, cytochrome P450
- CYP2C8
- DEAQ, desethylamodiaquine
- Enzyme inhibition
- HIM, human intestine microsomes
- HLM, human liver microsomes
- HPLC, high-performance liquid chromatography
- Hydroxypioglitazone
- IC50, concentration of inhibitor that results in 50% inhibition of reaction
- LC-MS/MS, liquid chromatography/tandem mass spectrometry
- M-IV, hydroxypioglitazone
- N-desethylamodiaquine
- Pioglitazone
- Pterostilbene
- RDI, recommended daily intake
- Serotonin
- Serotonin glucuronide
- UDPGA, uridine diphosphate glucuronic acid
- UGT, UDP-glucuronosyltransferase
- UGT1A6
- V/D, volume per dose index
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Affiliation(s)
- Ahmed A. Albassam
- Department of Clinical Pharmacy, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Gainesville, FL, USA
- Corresponding author at: Clinical Pharmacy, College of Pharmacy, Prince Sattam Bin Abdulaziz University, P.O. Box 173, Al-Kharj 11942, Saudi Arabia.
| | - Reginald F. Frye
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Gainesville, FL, USA
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25
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Ademisoye AA, Soyinka JO, Olawoye SO, Igbinoba SI, Olowookere SA, Ademisoye AT, Onyeji CO. Induction of Amodiaquine Metabolism by Rifampicin Following Concurrent Administration in Healthy Volunteers. JOURNAL OF EXPLORATORY RESEARCH IN PHARMACOLOGY 2018; 3:71-77. [DOI: 10.14218/jerp.2017.00024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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26
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A Review of Pharmacogenetics of Antimalarials and Associated Clinical Implications. Eur J Drug Metab Pharmacokinet 2018; 42:745-756. [PMID: 28070879 DOI: 10.1007/s13318-016-0399-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Genetic variability in drug-metabolizing enzymes and drug transporters is known to influence the pharmacokinetics of many drugs. Antimalarial drugs are a class of agents known to utilize metabolic and elimination pathways prone to genetic variation. This paper aims to review the genetic variants affecting antimalarial medications and discuss their clinical implications. Data were identified for the genes coding for the cytochrome P450 (CYP) enzymes: CYP2C8, CYP2C19, CYP2A6, CYP2D6, CYP2B6, and the P-glycoprotein drug transporter. Adverse effects of amodiaquine were more common in patients with decreased CYP2C8 metabolism. CYP2C19 variants influenced the metabolism of proguanil but no differences in efficacy outcomes were observed. Ultra-metabolizers of CYP2A6 showed increased incidence of adverse effects of artesunate (prodrug for active metabolite, dihydroartemisinin). In the presence of efavirenz, mutations in CYP2B6 influenced the number of patients achieving day-7 lumefantrine concentrations above accepted therapeutic cut-offs. Lumefantrine concentrations were also influenced by ABCB1 variants in the presence of nevirapine. The most critical pharmacogenetic consideration identified was the association of glucose-6-phosphate dehydrogenase deficiency with development of hemolytic anemia and decreased hemoglobin levels in patients treated with primaquine or a combination of chlorproguanil-dapsone-artesunate. These findings demonstrate a need for close monitoring of patients originating from populations where genetic variation in metabolizing enzymes is prevalent, so as to ensure that optimal clinical outcomes are achieved. Future studies should determine which populations are at greatest risk of potential treatment failures and/or adverse effects, which drugs are most susceptible to genetic variation in metabolizing enzymes, and the impact of genetic influence on the efficacy and safety of first-line treatment regimens.
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Quang NN, Chavchich M, Anh CX, Birrell GW, van Breda K, Travers T, Rowcliffe K, Edstein MD. Comparison of the Pharmacokinetics and Ex Vivo Antimalarial Activities of Artesunate-Amodiaquine and Artemisinin-Piperaquine in Healthy Volunteers for Preselection Malaria Therapy. Am J Trop Med Hyg 2018; 99:65-72. [PMID: 29741150 DOI: 10.4269/ajtmh.17-0434] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The pharmacokinetics (PK) and ex vivo activity (pharmacodynamics [PD]) of two artemisinin combination therapies (ACTs) (artemisinin-piperaquine [ARN-PPQ] [Artequick®] and artesunate-amodiaquine [ARS-AQ] [Coarsucam™]) in healthy Vietnamese volunteers were compared following 3-day courses of the ACTs for the preselection of the drugs for falciparum malaria therapy. For PK analysis, serial plasma samples were collected from two separate groups of 22 volunteers after ACT administration. Of these volunteers, ex vivo activity was assessed in plasma samples from seven volunteers who received both ACTs. The area under the concentration-time curve (AUC0-∞) was 3.6-fold higher for dihydroartemisinin (active metabolite of ARS) than that for ARN, whereas the AUC0-∞ of desethylamodiaquine (active metabolite of AQ) was 2.0-fold lower than that of PPQ. Based on the 50% inhibitory dilution values of the volunteers' plasma samples collected from 0.25 to 3 hours after the last dose, the ex vivo activity of ARS-AQ was 2.9- to 16.2-fold more potent than that of ARN-PPQ against the drug-sensitive D6 Plasmodium falciparum line. In addition, at 1.5, 4.0, and 24 hours after the last dose, the ex vivo activity of ARS-AQ was 20.8-, 3.5-, and 8.5-fold more potent than that of ARN-PPQ against the ARN-sensitive MRA1239 line. By contrast, at 1.5 hours, the ex vivo activity of ARS-AQ was 5.4-fold more active than that of ARN-PPQ but had similar activities at 4 and 24 hours against the ARN-resistant MRA1240 line. The PK-PD data suggest that ARS-AQ possesses superior antimalarial activity than that of ARN-PPQ and would be the preferred ACT for further in vivo efficacy testing in multidrug-resistant falciparum malaria areas.
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Affiliation(s)
- Nguyen Ngoc Quang
- Institute for Clinical Infectious Diseases, Central Military Hospital 108, Hanoi, Vietnam
| | - Marina Chavchich
- Department of Drug Evaluation, Australian Army Malaria Institute, Brisbane, Australia
| | - Chu Xuan Anh
- Institute for Clinical Infectious Diseases, Central Military Hospital 108, Hanoi, Vietnam
| | - Geoffrey W Birrell
- Department of Drug Evaluation, Australian Army Malaria Institute, Brisbane, Australia
| | - Karin van Breda
- Department of Drug Evaluation, Australian Army Malaria Institute, Brisbane, Australia
| | - Thomas Travers
- Department of Drug Evaluation, Australian Army Malaria Institute, Brisbane, Australia
| | - Kerryn Rowcliffe
- Department of Drug Evaluation, Australian Army Malaria Institute, Brisbane, Australia
| | - Michael D Edstein
- Department of Drug Evaluation, Australian Army Malaria Institute, Brisbane, Australia
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28
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Polasek TM, Tucker GT, Sorich MJ, Wiese MD, Mohan T, Rostami‐Hodjegan A, Korprasertthaworn P, Perera V, Rowland A. Prediction of olanzapine exposure in individual patients using physiologically based pharmacokinetic modelling and simulation. Br J Clin Pharmacol 2018; 84:462-476. [PMID: 29194718 PMCID: PMC5809347 DOI: 10.1111/bcp.13480] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 11/21/2017] [Accepted: 11/22/2017] [Indexed: 12/15/2022] Open
Abstract
AIM The aim of the present study was to predict olanzapine (OLZ) exposure in individual patients using physiologically based pharmacokinetic modelling and simulation (PBPK M&S). METHODS A 'bottom-up' PBPK model for OLZ was constructed in Simcyp® (V14.1) and validated against pharmacokinetic studies and data from therapeutic drug monitoring (TDM). The physiological, demographic and genetic attributes of the 'healthy volunteer population' file in Simcyp® were then individualized to create 'virtual twins' of 14 patients. The predicted systemic exposure of OLZ in virtual twins was compared with measured concentration in corresponding patients. Predicted exposures were used to calculate a hypothetical decrease in exposure variability after OLZ dose adjustment. RESULTS The pharmacokinetic parameters of OLZ from single-dose studies were accurately predicted in healthy Caucasians [mean-fold errors (MFEs) ranged from 0.68 to 1.14], healthy Chinese (MFEs 0.82 to 1.18) and geriatric Caucasians (MFEs 0.55 to 1.30). Cumulative frequency plots of trough OLZ concentration were comparable between the virtual population and patients in a TDM database. After creating virtual twins in Simcyp®, the R2 values for predicted vs. observed trough OLZ concentrations were 0.833 for the full cohort of 14 patients and 0.884 for the 7 patients who had additional cytochrome P450 2C8 genotyping. The variability in OLZ exposure following hypothetical dose adjustment guided by PBPK M&S was twofold lower compared with a fixed-dose regimen - coefficient of variation values were 0.18 and 0.37, respectively. CONCLUSIONS Olanzapine exposure in individual patients was predicted using PBPK M&S. Repurposing of available PBPK M&S platforms is an option for model-informed precision dosing and requires further study to examine clinical potential.
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Affiliation(s)
- Thomas M. Polasek
- Department of Clinical PharmacologyFlinders UniversityAdelaideSAAustralia
- d3 MedicineA Certara CompanyMelbourneVICAustralia
| | - Geoffrey T. Tucker
- Medicine and Biomedical Sciences (Emeritus)University of SheffieldSheffieldUK
| | - Michael J. Sorich
- Department of Clinical PharmacologyFlinders UniversityAdelaideSAAustralia
- Flinders Centre for Innovation in CancerFlinders UniversityAdelaideSAAustralia
| | - Michael D. Wiese
- School of Pharmacy and Medical SciencesUniversity of South AustraliaAdelaideSAAustralia
| | - Titus Mohan
- Department of PsychiatryFlinders Medical CentreAdelaideSAAustralia
| | - Amin Rostami‐Hodjegan
- Certara, Blades Enterprise CentreSheffieldUK
- Centre for Applied Pharmacokinetic ResearchUniversity of ManchesterManchesterUK
| | | | - Vidya Perera
- Clinical Pharmacology and Pharmacometrics, Early Clinical and Translational ResearchBristol Myers SquibbPrincetonNJUSA
| | - Andrew Rowland
- Department of Clinical PharmacologyFlinders UniversityAdelaideSAAustralia
- Flinders Centre for Innovation in CancerFlinders UniversityAdelaideSAAustralia
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Artesunate/Amodiaquine-Induced Acute Extrapyramidal Reactions in Children and Younger Adults: Case Series Assessment. Drug Saf 2017; 39:763-8. [PMID: 27206726 DOI: 10.1007/s40264-016-0429-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Several studies conducted in African countries reported the artesunate and amodiaquine (AS/AQ) tablet as a safe and well-tolerated anti-malarial drug in children and younger adults. The aim of this case series assessment was to assess the causal relationship between the AS/AQ tablet and extrapyramidal reactions in children and younger adults and to investigate the factor(s) predisposing to the adverse drug reactions. METHODS The causal relationship of all the cases was first assessed individually using the Naranjo Probability Scale and then subjected to a case series assessment using Austin Bradford-Hill criteria. RESULTS A total of 43 acute extrapyramidal reactions associated with the AS/AQ tablet were reported between 2012 and 16 November, 2015 to the Eritrean Pharmacovigilance Centre. The causality was found to be probable or highly probable for 33 (76.7 %) of the cases and the rest (10; 23.3 %) of the cases had a possible causal association. The extrapyramidal reactions had more or less similar clinical features in most of the cases and were characterized by abnormal involuntary contractions of muscles. The median age and body weight of the cases were 15 years and 40 kg, respectively, and 70 % of them were males. 90.7% of the reactions manifested in children and younger adults (aged <26 years). In most of the cases, reactions manifested in the third day from the start of treatment and 88.3 % of cases were hospitalized. CONCLUSION The causal relationship between the AS/AQ tablet and extrapyramidal reactions in children and younger adults was found to be apparent and possibly owing to dose accumulation or an overdose of amodiaquine.
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Edema O, Adehin A, Adeagbo BA, Olugbade TA. Simultaneous determination of amodiaquine and pioglitazone on dried blood spots (DBS) by HPLC–DAD and its usefulness in pharmacokinetic studies. J LIQ CHROMATOGR R T 2017. [DOI: 10.1080/10826076.2017.1399416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Opeyemi Edema
- Department of Pharmaceutical Chemistry, Faculty of Pharmay, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Ayorinde Adehin
- Department of Pharmaceutical Chemistry, Faculty of Pharmay, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Babatunde Ayodeji Adeagbo
- Department of Pharmaceutical Chemistry, Faculty of Pharmay, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Tiwalade Adewale Olugbade
- Department of Pharmaceutical Chemistry, Faculty of Pharmay, Obafemi Awolowo University, Ile-Ife, Nigeria
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Haraya K, Kato M, Chiba K, Sugiyama Y. Prediction of inter-individual variability on the pharmacokinetics of CYP2C8 substrates in human. Drug Metab Pharmacokinet 2017; 32:277-285. [PMID: 29174535 DOI: 10.1016/j.dmpk.2017.09.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 07/06/2017] [Accepted: 09/06/2017] [Indexed: 01/10/2023]
Abstract
Inter-individual variability in pharmacokinetics can lead to unexpected side effects and treatment failure, and is therefore an important factor in drug development. CYP2C8 is a major drug-metabolizing enzyme known to be involved in the metabolism of over 100 drugs. In this study, we predicted the inter-individual variability in AUC/Dose of CYP2C8 substrates in healthy volunteers using the Monte Carlo simulation. Inter-individual variability in the hepatic intrinsic clearance of CYP2C8 substrates (CLint,h,2C8) was estimated from the inter-individual variability in pharmacokinetics of pioglitazone, which is a major CYP2C8 substrate. The coefficient of variation (CV) of CLint,h,2C8 was estimated to be 40%. Using this value, the CVs of AUC/Dose of other major CYP2C8 substrates, rosiglitazone and amodiaquine, were predicted to validate the estimated CV of CLint,h,2C8. As a result, the reported CVs of both substrates were within the 2.5-97.5 percentile range of the predicted CVs. Furthermore, the CVs of AUC/Dose of the CYP2C8 substrates loperamide and chloroquine, which are affected by renal clearance, were also successfully predicted. Combining this value with previously reported CVs of other CYPs, we were able to successfully predict the inter-individual variability in pharmacokinetics of various drugs in clinical.
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Affiliation(s)
- Kenta Haraya
- Chugai Pharmabody Research Pte. Ltd., Singapore.
| | | | - Koji Chiba
- Laboratory of Clinical Pharmacology, Yokohama University of Pharmacy, Yokohama, Japan; Sugiyama Laboratory, RIKEN Innovation Center, Research Cluster for Innovation, RIKEN, Yokohama, Japan
| | - Yuichi Sugiyama
- Sugiyama Laboratory, RIKEN Innovation Center, Research Cluster for Innovation, RIKEN, Yokohama, Japan
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Albassam AA, Frye RF, Markowitz JS. The effect of milk thistle (Silybum marianum) and its main flavonolignans on CYP2C8 enzyme activity in human liver microsomes. Chem Biol Interact 2017; 271:24-29. [PMID: 28457856 DOI: 10.1016/j.cbi.2017.04.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/27/2017] [Indexed: 01/04/2023]
Abstract
Milk thistle is a widely-consumed botanical used for an array of purported health benefits. The primary extract of milk thistle is termed silymarin, a complex mixture that contains a number of structurally-related flavonolignans, the flavonoid, taxifolin, and a number of other constituents. The major flavonolignans present in most extracts are silybin A, silybin B, isosilybin A and isosilybin B, silydianin, silychristin and isosilychristin. Silymarin itself has been reported to inhibit CYP2C8 activity in vitro, but the effect of the individual flavonolignans on this enzyme has not been studied. To investigate the effects of milk thistle extract and its main flavonolignans (silybin A, silybin B, isosilybin A and isosilybin B) on CYP2C8 activity at relevant concentrations, the effect of milk thistle extract and the flavonolignans on CYP2C8 enzyme activity was studied in vitro using human liver microsomes (HLM) incorporating an enzyme-selective substrate for CYP2C8, amodiaquine. Metabolite formation was analyzed using liquid chromatography-tandem mass spectrometry (LC/MS-MS). The concentration causing 50% inhibition of enzyme activity (IC50) was used to express the degree of inhibition. Isosilibinin, a mixture of the diastereoisomers isosilybin A and isosilybin B, was found to be the most potent inhibitor, followed by isosilybin B with IC50 values (mean ± SE) of 1.64 ± 0.66 μg/mL and 2.67 ± 1.18 μg/mL, respectively. The rank order of observed inhibitory potency after isosilibinin was silibinin > isosilybin A > silybin A > milk thistle extract > and silybin B. These in vitro results suggest a potentially significant inhibitory effect of isosilibinin and isosilybin B on CYP2C8 activity. However, the observed IC50 values are unlikely to be achieved in humans supplemented with orally administered milk thistle extracts due to the poor bioavailability of flavonolignans documented with most commercially available formulations.
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Affiliation(s)
- Ahmed A Albassam
- Department of Pharmacotherapy and Translational Research, University of Florida College of Pharmacy, Gainesville, FL, USA; Department of Clinical Pharmacy, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia.
| | - Reginald F Frye
- Department of Pharmacotherapy and Translational Research, University of Florida College of Pharmacy, Gainesville, FL, USA
| | - John S Markowitz
- Department of Pharmacotherapy and Translational Research, University of Florida College of Pharmacy, Gainesville, FL, USA
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Peterson A, Xia Z, Chen G, Lazarus P. In vitro metabolism of exemestane by hepatic cytochrome P450s: impact of nonsynonymous polymorphisms on formation of the active metabolite 17 β-dihydroexemestane. Pharmacol Res Perspect 2017; 5:e00314. [PMID: 28603633 PMCID: PMC5464343 DOI: 10.1002/prp2.314] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 03/24/2017] [Indexed: 11/29/2022] Open
Abstract
Exemestane (EXE) is an endocrine therapy commonly used by postmenopausal women with hormone‐responsive breast cancer due to its potency in inhibiting aromatase‐catalyzed estrogen synthesis. Preliminary in vitro studies sought to identify phase I EXE metabolites and hepatic cytochrome P450s (CYP450s) that participate in EXE biotransformation. Phase I metabolites were identified by incubating EXE with HEK293‐overexpressed CYP450s. CYP450s 1A2, 2C8, 2C9, 2C19, 2D6, 3A4, and 3A5 produce 17β‐dihydroexemestane (17β‐DHE), an active major metabolite, as well as two inactive metabolites. 17β‐DHE formation in pooled human liver microsomes subjected to isoform‐specific CYP450 inhibition was also monitored using tandem mass spectrometry. 17β‐DHE production in human liver microsomes was unaffected by isoform‐specific inhibition of CYP450s 2A6, 2B6, and 2E1 but decreased 12–39% following inhibition of drug‐metabolizing enzymes from CYP450 subfamilies 1A, 2C, 2D, and 3A. These results suggest that redundancy exists in the EXE metabolic pathway with multiple hepatic CYP450s catalyzing 17β‐DHE formation in vitro. To further expand the knowledge of phase I EXE metabolism, the impact of CYP450 genetic variation on 17β‐DHE formation was assessed via enzyme kinetic parameters. Affinity for EXE substrate and enzyme catalytic velocity were calculated for hepatic wild‐type CYP450s and their common nonsynonymous variants by monitoring the reduction of EXE to 17β‐DHE. Several functional polymorphisms in xenobiotic‐metabolizing CYP450s 1A2, 2C8, 2C9, and 2D6 resulted in deviant enzymatic activity relative to wild‐type enzyme. Thus, it is possible that functional polymorphisms in EXE‐metabolizing CYP450s contribute to inter‐individual variability in patient outcomes by mediating overall exposure to the drug and its active metabolite, 17β‐DHE.
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Affiliation(s)
- Amity Peterson
- Department of Pharmaceutical Sciences Washington State University Spokane Washington
| | - Zuping Xia
- Department of Pharmaceutical Sciences Washington State University Spokane Washington
| | - Gang Chen
- Department of Pharmaceutical Sciences Washington State University Spokane Washington
| | - Philip Lazarus
- Department of Pharmaceutical Sciences Washington State University Spokane Washington
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Seden K, Gibbons S, Marzolini C, Schapiro JM, Burger DM, Back DJ, Khoo SH. Development of an evidence evaluation and synthesis system for drug-drug interactions, and its application to a systematic review of HIV and malaria co-infection. PLoS One 2017; 12:e0173509. [PMID: 28334018 PMCID: PMC5363796 DOI: 10.1371/journal.pone.0173509] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 02/21/2017] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND In all settings, there are challenges associated with safely treating patients with multimorbidity and polypharmacy. The need to characterise, understand and limit harms resulting from medication use is therefore increasingly important. Drug-drug interactions (DDIs) are prevalent in patients taking antiretrovirals (ARVs) and if unmanaged, may pose considerable risk to treatment outcome. One of the biggest challenges in preventing DDIs is the substantial gap between theory and clinical practice. There are no robust methods published for formally assessing quality of evidence relating to DDIs, despite the diverse sources of information. We defined a transparent, structured process for developing evidence quality summaries in order to guide therapeutic decision making. This was applied to a systematic review of DDI data with considerable public health significance: HIV and malaria. METHODS AND FINDINGS This was a systematic review of DDI data between antiretrovirals and drugs used in prophylaxis and treatment of malaria. The data comprised all original research in humans that evaluated pharmacokinetic data and/or related adverse events when antiretroviral agents were combined with antimalarial agents, including healthy volunteers, patients with HIV and/or malaria, observational studies, and case reports. The data synthesis included 36 articles and conference presentations published via PubMed and conference websites/abstract books between 1987-August 2016. There is significant risk of DDIs between HIV protease inhibitors, or NNRTIs and artemesinin-containing antimalarial regimens. For many antiretrovirals, DDI studies with antimalarials were lacking, and the majority were of moderate to very low quality. Quality of evidence and strength of recommendation categories were defined and developed specifically for recommendations concerning DDIs. CONCLUSIONS There is significant potential for DDIs between antiretrovirals and antimalarials. The application of quality of evidence and strength of recommendation criteria to DDI data is feasible, and allows the assessment of DDIs to be robust, consistent, transparent and evidence-based.
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Affiliation(s)
- Kay Seden
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Sara Gibbons
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Catia Marzolini
- Division of Infectious Diseases and Hospital Epidemiology, Departments of Medicine and Clinical Research, University Hospital of Basel, Basel, Switzerland
| | | | - David M. Burger
- Department of Pharmacy & Radboud Institute of Health Sciences (RIHS), Radboud University Medical Centre, Nijmegen, the Netherlands
| | - David J. Back
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Saye H. Khoo
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
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African Genetic Diversity: Implications for Cytochrome P450-mediated Drug Metabolism and Drug Development. EBioMedicine 2017; 17:67-74. [PMID: 28237373 PMCID: PMC5360579 DOI: 10.1016/j.ebiom.2017.02.017] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 02/17/2017] [Accepted: 02/17/2017] [Indexed: 12/17/2022] Open
Abstract
Genetic diversity is greater in Africa than in other continental populations. Genetic variability in genes encoding drug metabolizing enzymes may contribute to the high numbers of adverse drug reactions reported in Africa. We reviewed publications (1995-April 2016) reporting frequencies of known cytochrome P450 (CYP) variants in African populations. Using principal components analysis (PCA) we identified CYP alleles of potential clinical relevance with a marked difference in distribution in Africa, compared with Asian and Caucasian populations. These were CYP2B6*6, CYP2C8*2, CYP2D6*3, CYP2D6*17, CYP2D6*29, CYP3A5*6, and CYP3A5*7. We show clearly that there is greater diversity in CYP distribution in Africa than in other continental populations and identify a need for optimization of drug therapy and drug development there. Further pharmacogenetic studies are required to confirm the CYP distributions we identified using PCA, to discover uniquely African alleles and to identify populations at a potentially increased risk of drug-induced adverse events or drug inefficacy.
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36
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Pharmacogenomic implications of the evolutionary history of infectious diseases in Africa. THE PHARMACOGENOMICS JOURNAL 2016; 17:112-120. [PMID: 27779243 PMCID: PMC5380847 DOI: 10.1038/tpj.2016.78] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 07/06/2016] [Accepted: 07/19/2016] [Indexed: 12/20/2022]
Abstract
As the common birthplace of all human populations, modern humans have lived longer on the African continent than in any other geographical region of the world. This long history, along with the evolutionary need to adapt to environmental challenges such as exposure to infectious agents, has led to greater genetic variation in Africans. The vast genetic variation in Africans also extends to genes involved in the absorption, distribution, metabolism and excretion of pharmaceuticals. Ongoing cataloging of these clinically relevant variants reveals huge allele-frequency differences within and between African populations. Here, we examine Africa's large burden of infectious disease, discuss key examples of known genetic variation modulating disease risk, and provide examples of clinically relevant variants critical for establishing dosing guidelines. We propose that a more systematic characterization of the genetic diversity of African ancestry populations is required if the current benefits of precision medicine are to be extended to these populations.
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Sortica VA, Lindenau JD, Cunha MG, Ohnishi MDO, Ventura AMR, Ribeiro-Dos-Santos ÂK, Santos SE, Guimarães LS, Hutz MH. The effect of SNPs in CYP450 in chloroquine/primaquine Plasmodium vivax malaria treatment. Pharmacogenomics 2016; 17:1903-1911. [PMID: 27767381 PMCID: PMC7099632 DOI: 10.2217/pgs-2016-0131] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Background: Chloroquine/primaquine is the current therapy to eliminate Plasmodium vivax infection in the Amazon region. Aims: This study investigates CYP1A2, CYP2C8, CYP2C9, CYP3A4 and CYP3A5 genetic polymorphisms influence on cloroquine/primaquine treatment. Patients & methods: Generalized estimating equations analyses were performed to determine the genetic influence in parasitemia and/or gametocytemia clearance over treatment time in 164 patients. Results: An effect of CYP2C8 low-activity alleles on treatment was observed (p = 0.01). From baseline to first day of treatment, wild-type individuals achieved greater reduction of gametocytes than low-activity allele carriers. CYP2C9 and CYP3A5 genes showed a trend for gametocytemia and parasitemia clearance rates. Conclusion: Future studies should be performed to access the extent of CYP2C8, CYP2C9 and CYP3A5 gene polymorphisms influence on cloroquine/primaquine treatment.
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Affiliation(s)
- Vinicius A Sortica
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Juliana D Lindenau
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Maristela G Cunha
- Laboratório de Microbiologia e Imunologia, Universidade Federal do Pará, Belém, PA, Brazil
| | - Maria DO Ohnishi
- Programa de Ensaios Clínicos em Malária, Instituto Evandro Chagas, Sistema de Vigilância Sanitária, Ministério da Saúde, Ananindeua, PA, Brazil
| | - Ana Maria R Ventura
- Programa de Ensaios Clínicos em Malária, Instituto Evandro Chagas, Sistema de Vigilância Sanitária, Ministério da Saúde, Ananindeua, PA, Brazil
| | | | - Sidney Eb Santos
- Laboratório de Genética Humana e Médica, Universidade Federal do Pará, Belém, PA, Brazil
| | - Luciano Sp Guimarães
- Unidade de Bioestatística, Grupo de Pesquisa e Pós Graduação, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Mara H Hutz
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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NDiaye JL, Cissé B, Ba EH, Gomis JF, Ndour CT, Molez JF, Fall FB, Sokhna C, Faye B, Kouevijdin E, Niane FK, Cairns M, Trape JF, Rogier C, Gaye O, Greenwood BM, Milligan PJM. Safety of Seasonal Malaria Chemoprevention (SMC) with Sulfadoxine-Pyrimethamine plus Amodiaquine when Delivered to Children under 10 Years of Age by District Health Services in Senegal: Results from a Stepped-Wedge Cluster Randomized Trial. PLoS One 2016; 11:e0162563. [PMID: 27764102 PMCID: PMC5072628 DOI: 10.1371/journal.pone.0162563] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 08/08/2016] [Indexed: 11/18/2022] Open
Abstract
Background It is recommended that children aged 3 months to five years of age living in areas of seasonal transmission in the sub-Sahel should receive Seasonal Malaria Chemoprevention (SMC) with sulfadoxine-pyrimethamine plus amodiaquine (SPAQ) during the malaria transmission season. The purpose of this study was to evaluate the safety of SMC with SPAQ in children when delivered by community health workers in three districts in Senegal where SMC was introduced over three years, in children from 3 months of age to five years of age in the first year, then in children up to 10 years of age. Methods A surveillance system was established to record all deaths and all malaria cases diagnosed at health facilities and a pharmacovigilance system was established to detect adverse drug reactions. Health posts were randomized to introduce SMC in a stepped wedge design. SMC with SPAQ was administered once per month from September to November, by nine health-posts in 2008, by 27 in 2009 and by 45 in 2010. Results After three years, 780,000 documented courses of SMC had been administered. High coverage was achieved. No serious adverse events attributable to the intervention were detected, despite a high level of surveillance. Conclusions SMC is being implemented in countries of the sub-Sahel for children under 5 years of age, but in some areas the age distribution of cases of malaria may justify extending this age limit, as has been done in Senegal. Our results show that SMC is well tolerated in children under five and in older children. However, pharmacovigilance should be maintained where SMC is implemented and provision for strengthening national pharmacovigilance systems should be included in plans for SMC implementation. Trial Registration ClinicalTrials.gov NCT 00712374
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Affiliation(s)
- J. L. NDiaye
- Department of Parasitology, University Cheikh Anta Diop, Dakar, Senegal
| | - B. Cissé
- Department of Parasitology, University Cheikh Anta Diop, Dakar, Senegal
- Institut Pasteur, Antananarivo, Madagascar
| | - E. H. Ba
- Institut de Recherche pour le Développement, Dakar, Sénégal
| | - J. F. Gomis
- Institut de Recherche pour le Développement, Dakar, Sénégal
| | - C. T. Ndour
- Department of Parasitology, University Cheikh Anta Diop, Dakar, Senegal
| | - J. F. Molez
- Institut de Recherche pour le Développement, Dakar, Sénégal
| | - F. B. Fall
- National Malaria Control Program, Ministry of Health and Prevention, Dakar, Senegal
| | - C. Sokhna
- Institut de Recherche pour le Développement, Dakar, Sénégal
| | - B. Faye
- Department of Parasitology, University Cheikh Anta Diop, Dakar, Senegal
| | - E. Kouevijdin
- Institut de Recherche pour le Développement, Dakar, Sénégal
| | - F. K. Niane
- Department of Parasitology, University Cheikh Anta Diop, Dakar, Senegal
| | - M. Cairns
- London School of Hygiene &Tropical Medicine, London, United Kingdom
| | - J. F. Trape
- Institut de Recherche pour le Développement, Dakar, Sénégal
| | - C. Rogier
- Institut Pasteur, Antananarivo, Madagascar
| | - O. Gaye
- Department of Parasitology, University Cheikh Anta Diop, Dakar, Senegal
| | - B. M. Greenwood
- London School of Hygiene &Tropical Medicine, London, United Kingdom
| | - P. J. M. Milligan
- London School of Hygiene &Tropical Medicine, London, United Kingdom
- * E-mail:
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Backman JT, Filppula AM, Niemi M, Neuvonen PJ. Role of Cytochrome P450 2C8 in Drug Metabolism and Interactions. Pharmacol Rev 2016; 68:168-241. [PMID: 26721703 DOI: 10.1124/pr.115.011411] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
During the last 10-15 years, cytochrome P450 (CYP) 2C8 has emerged as an important drug-metabolizing enzyme. CYP2C8 is highly expressed in human liver and is known to metabolize more than 100 drugs. CYP2C8 substrate drugs include amodiaquine, cerivastatin, dasabuvir, enzalutamide, imatinib, loperamide, montelukast, paclitaxel, pioglitazone, repaglinide, and rosiglitazone, and the number is increasing. Similarly, many drugs have been identified as CYP2C8 inhibitors or inducers. In vivo, already a small dose of gemfibrozil, i.e., 10% of its therapeutic dose, is a strong, irreversible inhibitor of CYP2C8. Interestingly, recent findings indicate that the acyl-β-glucuronides of gemfibrozil and clopidogrel cause metabolism-dependent inactivation of CYP2C8, leading to a strong potential for drug interactions. Also several other glucuronide metabolites interact with CYP2C8 as substrates or inhibitors, suggesting that an interplay between CYP2C8 and glucuronides is common. Lack of fully selective and safe probe substrates, inhibitors, and inducers challenges execution and interpretation of drug-drug interaction studies in humans. Apart from drug-drug interactions, some CYP2C8 genetic variants are associated with altered CYP2C8 activity and exhibit significant interethnic frequency differences. Herein, we review the current knowledge on substrates, inhibitors, inducers, and pharmacogenetics of CYP2C8, as well as its role in clinically relevant drug interactions. In addition, implications for selection of CYP2C8 marker and perpetrator drugs to investigate CYP2C8-mediated drug metabolism and interactions in preclinical and clinical studies are discussed.
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Affiliation(s)
- Janne T Backman
- Department of Clinical Pharmacology, University of Helsinki (J.T.B., A.M.F., M.N., P.J.N.), and Helsinki University Hospital, Helsinki, Finland (J.T.B., M.N., P.J.N.)
| | - Anne M Filppula
- Department of Clinical Pharmacology, University of Helsinki (J.T.B., A.M.F., M.N., P.J.N.), and Helsinki University Hospital, Helsinki, Finland (J.T.B., M.N., P.J.N.)
| | - Mikko Niemi
- Department of Clinical Pharmacology, University of Helsinki (J.T.B., A.M.F., M.N., P.J.N.), and Helsinki University Hospital, Helsinki, Finland (J.T.B., M.N., P.J.N.)
| | - Pertti J Neuvonen
- Department of Clinical Pharmacology, University of Helsinki (J.T.B., A.M.F., M.N., P.J.N.), and Helsinki University Hospital, Helsinki, Finland (J.T.B., M.N., P.J.N.)
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Humphreys EH, Shah AR, Rutherford GW. Artemisinin-based combination therapy for uncomplicated P. falciparummalaria in children with HIV. Hippokratia 2016. [DOI: 10.1002/14651858.cd008556.pub2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Eliza H Humphreys
- University of California, San Francisco; Global Health Sciences; 50 Beale Street Suite 1200 San Francisco California USA 94105
| | - Anita R Shah
- Boston Children's Hospital; Boston Massachusetts USA
| | - George W Rutherford
- University of California, San Francisco; Global Health Sciences; 50 Beale Street Suite 1200 San Francisco California USA 94105
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Motshoge T, Tawe L, Muthoga CW, Allotey J, Romano R, Quaye I, Paganotti GM. Cytochrome P450 2C8*2 allele in Botswana: Human genetic diversity and public health implications. Acta Trop 2016; 157:54-8. [PMID: 26836270 DOI: 10.1016/j.actatropica.2016.01.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 01/18/2016] [Accepted: 01/27/2016] [Indexed: 11/26/2022]
Abstract
Human cytochrome P450 2C8 is a highly polymorphic gene and shows variation according to ethnicity. The CYP2C8*2 is a slow drug metabolism allele and shows 10-24% frequency in Black populations. The objective of this study was to assess the prevalence of CYP2C8*2 allele in Botswana among the San (or Bushmen) and the Bantu ethnic groups. For that purpose we recruited 544 children of the two ethnicities in three districts of Botswana from primary schools, collected blood samples, extracted DNA and genotyped them through PCR-based restriction fragment length polymorphism analysis. The results demonstrated that in the San the prevalence of the CYP2C8*2 allele is significantly higher than among the Bantu-related ethnic groups (17.5% and 8.5% for San and Bantu, respectively; P=0.00002). These findings support the evidence of a different genetic background of the San with respect to Bantu-related populations, and highlight a possible higher risk of longer drug clearance or poor level of activation of pro-drugs among the San group.
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In Vivo Efficacy of Artesunate/Sulphadoxine-Pyrimethamine versus Artesunate/Amodiaquine in the Treatment of Uncomplicated P. falciparium Malaria in Children around the Slope of Mount Cameroon: A Randomized Controlled Trial. Biomedicines 2016; 4:biomedicines4010005. [PMID: 28536372 PMCID: PMC5344242 DOI: 10.3390/biomedicines4010005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 01/31/2016] [Accepted: 02/04/2016] [Indexed: 11/21/2022] Open
Abstract
Background: The development and spread of antimalarial drug resistant parasites contributes to the global impact of the disease. In vivo efficacy assessments of treatments for Plasmodium falciparum malaria are essential for ensuring effective case management. Artemisinin-based combinations have been adopted as the first-line treatment for uncomplicated P. falciparum malaria in Cameroon since 2004. Methods: A total of 177 children aged six-months to 10 years with uncomplicated mono-infected falciparum malaria were randomized (1:1) to receive artesunate/sulphadoxine-pyrimethamine (AS/SP) or artesunate/amodiaquine (AS/AQ) pediatric tablets and followed up for 28 days according to the standard World Health Organization in vivo drug efficacy monitoring protocol. The primary and secondary endpoints were PCR uncorrected and corrected cure rates, as measured by adequate clinical and parasitological response (ACPR) on day 28. Results: The PCR corrected cure rate was high, overall (88.1%, 95% CI 83.1–93.1), 85.9% (95% CI 78.2–93.6), and 90.2% (95% CI 83.8–96.6) for AS/SP and AS/AQ, respectively. Twenty-one treatment failures were observed during follow-up, constituting one (4.6%), 14 (8.2%), and six (3.5%) early treatment failure (ETF), late clinical failure (LCF), and late parasitological failure (LPF), respectively. The drugs were well tolerated with no serious adverse events. Conclusions: Both AS/SP and AS/AQ are highly effective and well-tolerated treatments for uncomplicated P. falciparum malaria around the slope of Mount Cameroon.
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Implications of Pharmacogenetics for Antimicrobial Prescribing. Mol Microbiol 2016. [DOI: 10.1128/9781555819071.ch43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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44
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Beumer JH, Pillai VC, Parise RA, Christner SM, Kiesel BF, Rudek MA, Venkataramanan R. Human hepatocyte assessment of imatinib drug-drug interactions - complexities in clinical translation. Br J Clin Pharmacol 2015; 80:1097-108. [PMID: 26178713 DOI: 10.1111/bcp.12723] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 06/24/2015] [Accepted: 07/09/2015] [Indexed: 01/09/2023] Open
Abstract
AIM Inducers and inhibitors of CYP3A, such as ritonavir and efavirenz, may be used as part of the highly active antiretroviral therapy (HAART) to treat HIV patients. HIV patients with chronic myeloid leukemia or gastrointestinal stromal tumour may need imatinib, a CYP3A4 substrate with known exposure response-relationships. Administration of imatinib to patients on ritonavir or efavirenz may result in altered imatinib exposure leading to increased toxicity or failure of therapy, respectively. We used primary human hepatocyte cultures to evaluate the magnitude of interaction between imatinib and ritonavir/efavirenz. METHODS Hepatocytes were pre-treated with vehicle, ritonavir, ketoconazole, efavirenz or rifampicin, and the metabolism of imatinib was characterized over time. Concentrations of imatinib and metabolite were quantitated in combined lysate and medium, using LC-MS. RESULTS The predicted changes in imatinib CLoral (95% CI) with ketoconazole, ritonavir, rifampicin and efavirenz were 4.0-fold (0, 9.2) lower, 2.8-fold (0.04, 5.5) lower, 2.9-fold (2.2, 3.5) higher and 2.0-fold (0.42, 3.5) higher, respectively. These predictions were in good agreement with clinical single dose drug-drug interaction studies, but not with reports of imatinib interactions at steady-state. Alterations in metabolism were similar after acute or chronic imatinib exposure. CONCLUSIONS In vitro human hepatocytes predicted increased clearance of imatinib with inducers and decreased clearance with inhibitors of CYP enzymes. The impact of HAART on imatinib may depend on whether it is being initiated or has already been dosed chronically in patients. Therapeutic drug monitoring may have a role in optimizing imatinib therapy in this patient population.
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Affiliation(s)
- Jan H Beumer
- Department of Pharmaceutical Sciences, School of Pharmacy, Pittsburgh, PA.,Cancer Therapeutics program, University of Pittsburgh Cancer Institute, Pittsburgh, PA
| | | | - Robert A Parise
- Cancer Therapeutics program, University of Pittsburgh Cancer Institute, Pittsburgh, PA
| | - Susan M Christner
- Cancer Therapeutics program, University of Pittsburgh Cancer Institute, Pittsburgh, PA
| | - Brian F Kiesel
- Cancer Therapeutics program, University of Pittsburgh Cancer Institute, Pittsburgh, PA
| | | | - Raman Venkataramanan
- Department of Pharmaceutical Sciences, School of Pharmacy, Pittsburgh, PA.,Cancer Therapeutics program, University of Pittsburgh Cancer Institute, Pittsburgh, PA.,Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA
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Aung AK, Haas DW, Hulgan T, Phillips EJ. Pharmacogenomics of antimicrobial agents. Pharmacogenomics 2015; 15:1903-30. [PMID: 25495412 DOI: 10.2217/pgs.14.147] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Antimicrobial efficacy and toxicity varies between individuals owing to multiple factors. Genetic variants that affect drug-metabolizing enzymes may influence antimicrobial pharmacokinetics and pharmacodynamics, thereby determining efficacy and/or toxicity. In addition, many severe immune-mediated reactions have been associated with HLA class I and class II genes. In the last two decades, understanding of pharmacogenomic factors that influence antimicrobial efficacy and toxicity has rapidly evolved, leading to translational success such as the routine use of HLA-B*57:01 screening to prevent abacavir hypersensitivity reactions. This article examines recent advances in the field of antimicrobial pharmacogenomics that potentially affect treatment efficacy and toxicity, and challenges that exist between pharmacogenomic discovery and translation into clinical use.
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Affiliation(s)
- Ar Kar Aung
- Department of General Medicine & Infectious Diseases, The Alfred Hospital, Melbourne, Victoria, Australia
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Li B, Zhang J, Zhou XZ, Li JY, Yang YJ, Wei XJ, Niu JR, Liu XW, Li JS, Zhang JY. Determination and pharmacokinetic studies of artesunate and its metabolite in sheep plasma by liquid chromatography–tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2015; 997:146-53. [DOI: 10.1016/j.jchromb.2015.05.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 04/29/2015] [Accepted: 05/03/2015] [Indexed: 10/23/2022]
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Tsukada C, Saito T, Maekawa M, Mano N, Oda A, Hirasawa N, Hiratsuka M. Functional characterization of 12 allelic variants of CYP2C8 by assessment of paclitaxel 6α-hydroxylation and amodiaquine N-deethylation. Drug Metab Pharmacokinet 2015; 30:366-73. [PMID: 26427316 DOI: 10.1016/j.dmpk.2015.07.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/14/2015] [Accepted: 07/21/2015] [Indexed: 12/25/2022]
Abstract
Cytochrome P450 2C8 (CYP2C8) is one of the enzymes primarily responsible for the metabolism of many drugs, including paclitaxel and amodiaquine. CYP2C8 genetic variants contribute to interindividual variations in the therapeutic efficacy and toxicity of paclitaxel. Although it is difficult to investigate the enzymatic function of most CYP2C8 variants in vivo, this can be investigated in vitro using recombinant CYP2C8 protein variants. The present study used paclitaxel to evaluate 6α-hydroxylase activity and amodiaquine for the N-deethylase activity of wild-type and 11 CYP2C8 variants resulting in amino acid substitutions in vitro. The wild-type and variant CYP2C8 proteins were heterologously expressed in COS-7 cells. Paclitaxel 6α-hydroxylation and amodiaquine N-deethylation activities were determined by measuring the concentrations of 6α-hydroxypaclitaxel and N-desethylamodiaquine, respectively, and the kinetic parameters were calculated. Compared to the wild-type enzyme (CYP2C8.1), CYP2C8.11 and CYP2C8.14 showed little or no activity with either substrate. In addition, the intrinsic clearance values of CYP2C8.8 and CYP2C8.13 for paclitaxel were 68% and 67% that of CYP2C8.1, respectively. In contrast, the CLint values of CYP2C8.2 and CYP2C8.12 were 1.4 and 1.9 times higher than that of CYP2C8.1. These comprehensive findings could inform for further genotype-phenotype studies on interindividual differences in CYP2C8-mediated drug metabolism.
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Affiliation(s)
- Chiharu Tsukada
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Takahiro Saito
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Masamitsu Maekawa
- Department of Pharmacy, Tohoku University Hospital, Sendai 980-8574, Japan
| | - Nariyasu Mano
- Department of Pharmacy, Tohoku University Hospital, Sendai 980-8574, Japan
| | - Akifumi Oda
- Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa 920-1192, Japan
| | - Noriyasu Hirasawa
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Masahiro Hiratsuka
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan.
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Lee MY, Apellániz-Ruiz M, Johansson I, Vikingsson S, Bergmann TK, Brøsen K, Green H, Rodríguez-Antona C, Ingelman-Sundberg M. Role of cytochrome P450 2C8*3 (CYP2C8*3) in paclitaxel metabolism and paclitaxel-induced neurotoxicity. Pharmacogenomics 2015; 16:929-37. [PMID: 26115084 DOI: 10.2217/pgs.15.46] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AIM The CYP2C8*3 allele has been suggested as a risk factor for paclitaxel-induced neuropathy but the data hitherto published are conflicting. MATERIALS & METHODS In total 435 patients were investigated with respect to maximum neuropathy grade and accumulated paclitaxel dose. The enzymatic properties of CYP2C8.3 variant were analyzed using heterologous mammalian HEK293 cell expression system. RESULTS No significant association between CYP2C8*3 allele and neuropathy was found, although a trend was observed. The paclitaxel and amodiaquine metabolism by CYP2C8.3 were found similar to CYP2C8.1, whereas CYP2C8.3 was more efficient in the metabolism of rosiglitazone. CONCLUSION These results indicate a difference in substrate specificity between CYP2C8.1 and CYP2C8.3; however, the CYP2C8*3 allele has no major impact on paclitaxel metabolism in vitro or of paclitaxel-induced neuropathy in vivo. Original submitted on 6 February 2015; revision submitted on 9 April 2015.
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Affiliation(s)
- Mi-Young Lee
- Section of Pharmacogenetics, Department of Physiology & Pharmacology, Karolinska Institutet, SE 171 77 Stockholm, Sweden
| | - María Apellániz-Ruiz
- Hereditary Endocrine Cancer Group, Human Cancer Genetics Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Inger Johansson
- Section of Pharmacogenetics, Department of Physiology & Pharmacology, Karolinska Institutet, SE 171 77 Stockholm, Sweden
| | - Svante Vikingsson
- Clinical Pharmacology, Division of Drug Research, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Troels K Bergmann
- Research Unit of Clinical Pharmacology, Department of Public Health, University of Southern Denmark, Odense, Denmark
| | - Kim Brøsen
- Research Unit of Clinical Pharmacology, Department of Public Health, University of Southern Denmark, Odense, Denmark
| | - Henrik Green
- Clinical Pharmacology, Division of Drug Research, Faculty of Health Sciences, Linköping University, Linköping, Sweden.,Department of Forensic Genetics & Forensic Toxicology, National Board of Forensic Medicine, Linköping, Sweden
| | - Cristina Rodríguez-Antona
- Hereditary Endocrine Cancer Group, Human Cancer Genetics Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain.,ISCIII Center for Biomedical Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Magnus Ingelman-Sundberg
- Section of Pharmacogenetics, Department of Physiology & Pharmacology, Karolinska Institutet, SE 171 77 Stockholm, Sweden
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Albassam AA, Mohamed MEF, Frye RF. Inhibitory effect of six herbal extracts on CYP2C8 enzyme activity in human liver microsomes. Xenobiotica 2014; 45:406-12. [DOI: 10.3109/00498254.2014.989935] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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50
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Marwa KJ, Schmidt T, Sjögren M, Minzi OMS, Kamugisha E, Swedberg G. Cytochrome P450 single nucleotide polymorphisms in an indigenous Tanzanian population: a concern about the metabolism of artemisinin-based combinations. Malar J 2014; 13:420. [PMID: 25363545 PMCID: PMC4228099 DOI: 10.1186/1475-2875-13-420] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Accepted: 10/25/2014] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Artemisinin-based combinations currently recommended for treatment of uncomplicated Plasmodium falciparum malaria in many countries of sub-Saharan Africa are substrates of CYP enzymes. The cytochrome enzyme system is responsible for metabolism of about 80-90% of clinically used drugs. It is, therefore, important to obtain the pharmacogenetics of the population in the region with respect to these combinations and thereby enable practitioners to predict treatment outcomes. The aim of this study was to detect and determine allelic frequencies of CYP2C8*2, CYP2C8*3, CYP3A4*1B, CYP3A5*3 and CYP2B6*6 variant alleles in a Tanzanian indigenous population. METHODS Genomic DNA extraction from blood obtained from 256 participants who escorted patients at Karume Health Centre in Mwanza Tanzania, was carried out using the Gene JET™ Genomic DNA purification kit (Thermo Scientific). Genotyping for the cytochrome P450 variant alleles was performed using predesigned primers. Amplification was done by PCR while differentiation between alleles was done by restriction fragment length polymorphism (PCR-RFLP) (for CYP2C8*2, CYP2C8*3) and sequencing (for CYP2B6*6, CYP3A5*3 and CYP3A4*1B). RESULTS CYP2C8*2, CYP2C8*3, CYP3A5*3, CYP3A4*1B and CYP2B6*6 variant allelic frequencies were found to be 19,10,16,78 and 36% respectively. CONCLUSION Prevalence of CYP2C8*2, CYP3A5*3, CYP3A4*1B and CYP2B6*6 mutations in a Tanzanian population/subjects are common. The impact of these point mutations on the metabolism of anti-malarial drugs, particularly artemisinin-based combinations, and their potential drug-drug interactions (DDIs) needs to be further evaluated.
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Affiliation(s)
- Karol J Marwa
- Department of Pharmacology, Catholic University of Health and Allied Sciences, Mwanza, Tanzania.
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