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Dsouza D, K Sarma GR, Sebastian S, Prakash P. Efavirenz-Induced delayed onset cerebellar ataxia and encephalopathy. Ann Indian Acad Neurol 2022; 25:153-155. [PMID: 35342246 PMCID: PMC8954305 DOI: 10.4103/aian.aian_83_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/12/2021] [Accepted: 03/08/2021] [Indexed: 11/04/2022] Open
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Langaee T, Al-Shaer MH, Gong Y, Lima E, Antwi S, Enimil A, Dompreh A, Yang H, Alghamdi WA, Wiesner L, Peloquin CA, Kwara A. Pharmacogenetic predictors of nevirapine pharmacokinetics in Ghanaian children living with HIV with or without TB coinfection. INFECTION GENETICS AND EVOLUTION 2021; 92:104856. [PMID: 33839311 DOI: 10.1016/j.meegid.2021.104856] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 04/05/2021] [Accepted: 04/06/2021] [Indexed: 11/17/2022]
Abstract
Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor that is used in the treatment of human immunodeficiency virus (HIV) infection in children younger than 3 years old. Identifying genetic predictors of NVP pharmacokinetics (PK) in young children is important because inter-individual variability in NVP concentrations contributes to variable treatment response and the information may be used to individualize dosing decisions. We examined the relationship between genetic variations in relevant drug disposition genes and NVP PK parameters in Ghanaian children living with HIV eligible to initiate NVP-based antiretroviral therapy. Participants received NVP plus zidovudine and lamivudine or abacavir and lamivudine twice daily, and those with tuberculosis (TB) coinfection received concurrent anti-TB therapy with NVP. Pharmacokinetic sampling was performed after at least 4 weeks of antiretroviral therapy. Nevirapine minimum concentration (Cmin), area under the concentration-time curve from time 0 to 12 h (AUC0-12h), and apparent clearance (CL/F) were calculated using non-compartmental analysis using Phoenix v8.0 software. Genotyping for CYP2B6, CYP2A6, CYP3A5, ABCB1, NR1I2, and NR1I3 single nucleotide polymorphism (SNPs) was performed by TaqMan® allelic discrimination method. The median (range) NVP dose received was 10 (7-14) mg/kg. Of the 53 participants, the median (range) Cmin was 3.3 (0.0-14.0) mg/L and AUC0-12h was 56.0 (16.7-202.6) mg.hr/L. Using step-wise regression, CYP2B6 rs3745274 and NR1I2 rs6785049 SNPs were independent as well as joint predictors of NVP AUC0-12h, Cmin, and CL/F. We concluded that genotyping for CYP2B6 rs3745274, and the NR1I2 rs6785049 G > A SNP (which encodes the transcriptional factor, pregnane X receptor), could improve prediction of NVP PK for individualized therapy.
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Affiliation(s)
- Taimour Langaee
- College of Pharmacy, Department of Pharmacotherapy and Translational Research, Center for Pharmacogenomics and Precision Medicine, University of Florida, Gainesville, FL, United States
| | - Mohammad H Al-Shaer
- Department of Pharmacotherapy and Translational Research, University of Florida, Gainesville, FL, United States
| | - Yan Gong
- College of Pharmacy, Department of Pharmacotherapy and Translational Research, Center for Pharmacogenomics and Precision Medicine, University of Florida, Gainesville, FL, United States
| | - Elizabeth Lima
- College of Pharmacy, Department of Pharmacotherapy and Translational Research, Center for Pharmacogenomics and Precision Medicine, University of Florida, Gainesville, FL, United States; Ohio State University, Columbus, OH, United States
| | - Sampson Antwi
- Directorate of Child Health, Komfo Anokye Teaching Hospital, Kumasi, Ghana; Department of Child Health, School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Anthony Enimil
- Directorate of Child Health, Komfo Anokye Teaching Hospital, Kumasi, Ghana; Department of Child Health, School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Albert Dompreh
- Serology Unit, Department of Clinical Microbiology, Komfo Anokye Teaching Hospital, Kumasi, Ghana
| | - Hongmei Yang
- Department of Biostatistics and Computational Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY, United States
| | - Wael A Alghamdi
- Department of Clinical Pharmacy, College of Pharmacy, King Khalid University, Abha, Saudi Arabia
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Charles A Peloquin
- Department of Pharmacotherapy and Translational Research, University of Florida, Gainesville, FL, United States
| | - Awewura Kwara
- Department of Medicine, College of Medicine, University of Florida, Gainesville, FL, United States.
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Haas DW, Podany AT, Bao Y, Swindells S, Chaisson RE, Mwelase N, Supparatpinyo K, Mohapi L, Gupta A, Benson CA, Baker P, Fletcher CV. Pharmacogenetic interactions of rifapentine plus isoniazid with efavirenz or nevirapine. Pharmacogenet Genomics 2021; 31:17-27. [PMID: 32815870 PMCID: PMC7655626 DOI: 10.1097/fpc.0000000000000417] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVES The effect of rifapentine plus isoniazid on efavirenz pharmacokinetics was characterized in AIDS Clinical Trials Group protocol A5279 (NCT01404312). The present analyses characterize pharmacogenetic interactions between these drugs, and with nevirapine. METHODS A subset of HIV-positive individuals receiving efavirenz- or nevirapine-containing antiretroviral therapy in A5279 underwent pharmacokinetic evaluations at baseline, and again weeks 2 and 4 after initiating daily rifapentine plus isoniazid. Associations with polymorphisms relevant to efavirenz, nevirapine, isoniazid, and rifapentine pharmacokinetics were assessed. RESULTS Of 128 participants, 101 were evaluable for associations with rifapentine and its active 25-desacetyl metabolite, 87 with efavirenz, and 38 with nevirapine. In multivariable analyses, NAT2 slow acetylators had greater week 4 plasma concentrations of rifapentine (P = 2.6 × 10) and 25-desacetyl rifapentine (P = 7.0 × 10) among all participants, and in efavirenz and nevirapine subgroups. NAT2 slow acetylators also had greater plasma efavirenz and nevirapine concentration increases from baseline to week 4, and greater decreases from baseline in clearance. CYP2B6 poor metabolizers had greater efavirenz concentrations at all weeks and greater nevirapine concentrations at baseline. None of 47 additional polymorphisms in 11 genes were significantly associated with pharmacokinetics. CONCLUSIONS Among HIV-positive individuals receiving efavirenz or nevirapine, and who then initiated rifapentine plus isoniazid in A5279, NAT2 slow acetylators had greater rifapentine and 25-desacetyl rifapentine concentrations, and greater increases from baseline in plasma efavirenz and nevirapine concentrations. These associations are likely mediated by greater isoniazid exposure in NAT2 slow acetylators.
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Affiliation(s)
- David W Haas
- Department of Medicine, Vanderbilt University School of Medicine
| | - Anthony T Podany
- Department of Pharmacy Practice and Science, Antiviral Pharmacology Laboratory, UNMC Center for Drug Discovery, University of Nebraska Medical Center, Omaha
| | - Yajing Bao
- Statistical and Data Analysis Center, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Susan Swindells
- Infectious Diseases, Internal Medicine, University of Nebraska Medical Center, Omaha
| | - Richard E Chaisson
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Noluthando Mwelase
- Helen Joseph Hospital, University of Witwatersrand University, Johannesburg, South Africa
| | - Khuanchai Supparatpinyo
- Department of Medicine, Research Institute for Health Sciences and Faculty of Medicine, Chiang Mai University, Thailand
| | - Lerato Mohapi
- Perinatal HIV Research Unit, University of the Witwatersrand and Chris Hani Baragwanath Hospital, Soweto, South Africa
| | - Amita Gupta
- Department of Medicine, Center for Clinical Global Health Education, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Constance A Benson
- Departments of Medicine and Global Public Health, Antiviral Research Center, University of California, San Diego
| | - Paxton Baker
- Vanderbilt Technologies for Advanced Genomics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Courtney V Fletcher
- Department of Pharmacy Practice and Science, Antiviral Pharmacology Laboratory, UNMC Center for Drug Discovery, University of Nebraska Medical Center, Omaha; for the AIDS Clinical Trials Group A5279 Study Team
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Tuberculosis research conducted over the years at the ICMR-National Institute for Research in Tuberculosis (ICMR-NIRT). Indian J Tuberc 2020; 67:S7-S15. [PMID: 33308675 DOI: 10.1016/j.ijtb.2020.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review article highlights some of the key research conducted at the ICMR-National Institute for Research in Tuberculosis (ICMR-NIRT) over the years since its inception in 1956 till the present. The research carried out in the field of tuberculosis at ICMR-NIRT has been a joint effort between the ICMR, NIRT, the TB control program in India with assistance from World Health Organization (WHO) and the National Institutes of Health (NIH), USA. The research carried out at ICMR-NIRT has helped to formulate the national guidelines for the control and the management of tuberculosis in India. The major highlights of the research carried out at ICMR-NIRT are provided in this manuscript.
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Tan M, Bowers M, Thuma P, Grigorenko EL. The Pharmacogenetics of Efavirenz Metabolism in Children: The Potential Genetic and Medical Contributions to Child Development in the Context of Long-Term ARV Treatment. New Dir Child Adolesc Dev 2020; 2020:107-133. [PMID: 32657046 DOI: 10.1002/cad.20353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Efavirenz (EFV) is a well-known, effective anti-retroviral drug long used in first-line treatment for children and adults with HIV and HIV/AIDS. Due to its narrow window of effective concentrations, between 1 and 4 μg/mL, and neurological side effects at supratherapeutic levels, several investigations into the pharmacokinetics of the drug and its genetic underpinnings have been carried out, primarily with adult samples. A number of studies, however, have examined the genetic influences on the metabolism of EFV in children. Their primary goal has been to shed light on issues of appropriate pediatric dosing, as well as the manifestation of neurotoxic effects of EFV in some children. Although EFV is currently being phased out of use for the treatment of both adults and children, we share this line of research to highlight an important aspect of medical treatment that is relevant to understanding the development of children diagnosed with HIV.
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Singh H, Lata S, Dhole TN, Gangakhedkar RR. Occurrence of CYP2B6 516G>T polymorphism in patients with ARV-associated hepatotoxicity. Mol Genet Genomic Med 2019; 7:e00598. [PMID: 30864294 PMCID: PMC6465650 DOI: 10.1002/mgg3.598] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 11/14/2018] [Accepted: 01/10/2019] [Indexed: 01/11/2023] Open
Abstract
Background Hepatic enzyme cytochrome P450 2B6 (CYP2B6) plays a role in the metabolism of efavirenz drugs. CYP2B6 516G>T variation showed an implication for HIV treatment. Methods CYP2B6 516G>T polymorphism was genotyped in a total 165 HIV patients that include 34 with and 131 without hepatotoxicity and 155 healthy individuals by the PCR‐RFLP. Results In patients with hepatotoxicity, the prevalence of CYP2B6 516TT genotype was higher as compared to healthy individuals (35.3% vs. 30.5%, OR = 1.74). Patients with hepatotoxicity using tobacco had a higher prevalence of genotypes CYP2B6 516GT, 516TT, 516GT+TT as compared to healthy individuals (28.57% vs. 25.93%; 57.14% vs. 29.63%; 85.71% vs. 55.56%). Likewise, hepatotoxicity in patients consuming alcohol showed higher distributions of CYP2B6 516GT, 516TT, 516GT+TT genotypes (57% vs. 25.93%; 42.86% vs. 33.33%; 71.43% vs. 59.26%). Nevirapine users with hepatotoxicity overrepresented genotypes CYP2B6 TT and 516GT+TT as compared to efavirenz users (47.83% vs. 45.45%, OR = 6.88, 65.22% vs. 54.55%, OR = 1.56). Similarly, in nevirapine +alcohol users with hepatotoxicity, the frequency of CYP2B6 516GT, 516GT+TT genotypes was higher than with nevirapine +alcohol nonusers (40.0% vs. 11.11%, OR = 8.00, 80.0% vs. 27.78%, OR = 4.00). In HIV patients, nevirapine users had higher frequency of CYP2B6 516GT, 516GT+TT genotypes as compared to efavirenz users (42.02% vs. 25.00%, OR = 2.53; 72.27% vs. 58.33%, OR = 1.86). Likewise, in HIV patients, genotypes CYP2B6 516GT, 516GT+TT were predominant with nevirapine +alcohol users as compared to nevirapine +alcohol nonusers (57.89% vs. 34.57%, OR = 2.46; 78.95% vs. 69.14%, OR = 1.67). In multivariate logistic regression, taking nevirapine had a protection for severity of ARV‐associated hepatotoxicity (OR = 0.23, p = 0.005). Conclusions No significant association was detected between CYP2B6 516G>T polymorphism and susceptibility to ARV‐associated hepatotoxicity.
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Affiliation(s)
- HariOm Singh
- Department of Molecular Biology, National AIDS Research Institute, Pune, India
| | - Sonam Lata
- Department of Molecular Biology, National AIDS Research Institute, Pune, India
| | - T N Dhole
- Department of Microbiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
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Singh H, Lata S, Gangakhedkar RR. Prevalence of CYP2D6*4 1934G/A polymorphism in Western Indian HIV patients. APMIS 2018; 126:842-851. [PMID: 30357957 DOI: 10.1111/apm.12893] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 06/18/2018] [Indexed: 01/11/2023]
Abstract
Hepatic CYP2D6 enzyme metabolizes antiretroviral drugs (ARVs) including nevirapine. Polymorphism in CYP2D6 gene affects drug metabolism and displays distinctive phenotypes in the population. Hence, we investigated the prevalence of CYP2D6*4 1934G/A polymorphism in a total of 165 HIV patients that include 34 with and 131 without hepatotoxicity and 160 unrelated healthy controls by the PCR-RFLP method. The prevalence of CYP2D6*4 1934AA genotype was higher in total HIV patients as compared to healthy controls (1.81% vs 0.6%, OR = 2.86). Similarly, CYP2D6*4 1934AA genotype was much more prevalent in HIV patients without hepatotoxicity as compared to healthy controls (2.3% vs 0.6%, OR = 2.87). Likewise, CYP2D6*4 1934AA genotype was predominant in advanced HIV disease stage as compared to healthy controls (3.8% vs 0.6%, OR = 6.15). CYP2D6*4 1934GA genotype was distributed higher in HIV patients taking tobacco and nevirapine as compared to non-users (23.3% vs 19.3%, OR = 1.21, 21.0% vs 16.7%, OR = 1.2). Likewise, CYP2D6*4 1934GA genotype was overrepresented in patients with hepatotoxicity taking alcohol + nevirapine as compared to alcohol non-users + nevirapine users (20.00% vs 16.67%, OR = 1.25). Thus, there was no significant difference in genotype or allele frequencies of CYP2D6*4 1934G/A polymorphism between the patients with hepatotoxicity and those without or healthy controls.
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Affiliation(s)
- HariOm Singh
- Department of Molecular Biology, National AIDS Research Institute, Pune, India
| | - Sonam Lata
- Department of Molecular Biology, National AIDS Research Institute, Pune, India
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Dalwadi DA, Ozuna L, Harvey BH, Viljoen M, Schetz JA. Adverse Neuropsychiatric Events and Recreational Use of Efavirenz and Other HIV-1 Antiretroviral Drugs. Pharmacol Rev 2018; 70:684-711. [DOI: 10.1124/pr.117.013706] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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Gopalan BP, Mehta K, D'souza RR, Rajnala N, A. K. HK, Ramachandran G, Shet A. Sub-therapeutic nevirapine concentration during antiretroviral treatment initiation among children living with HIV: Implications for therapeutic drug monitoring. PLoS One 2017; 12:e0183080. [PMID: 28827836 PMCID: PMC5565187 DOI: 10.1371/journal.pone.0183080] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 07/29/2017] [Indexed: 12/04/2022] Open
Abstract
Nevirapine, a component of antiretroviral therapy (ART) in resource-limited settings, known for auto-induction of metabolism, is initiated at half therapeutic dose until day 14 (‘lead-in period’), and subsequently escalated to full dose. However, studies have shown that this dosing strategy based on adult studies may not be appropriate in children, given that younger children have higher drug clearance rates. In this prospective cohort study, we studied trough plasma nevirapine levels by high performance liquid chromatography (HPLC) at days 7, 14 (lead-in period) and 28 (full dose period) after ART initiation amongst HIV-1 infected children initiating nevirapine-based ART in southern India. Among the 20 children (50% male, median age 9 years) included in the study, sub-therapeutic trough plasma nevirapine concentration (<4μg/ml) was seen in 65% (13/20) of children during the lead-in period within two weeks of ART initiation and among 10% of children at 4 weeks during full-dose nevirapine. Adherence was documented as ≥95% in all children by both caregiver self-report and pill count. Median nevirapine concentrations achieved at week 1 was 4.8 μg/ml, significantly lower than 8 μg/ml, the concentration achieved at week 4 (p = 0.034). Virological failure at one year of ART was observed in six children, and was not associated with median nevirapine concentration achieved during week 1, 2 or 4. We conclude that the dose escalation strategy currently practiced among young children living with HIV-1 resulted in significant subtherapeutic nevirapine concentration (≤4μg/ml) during the lead-in period. We call for a closer look at pediatric-focused dosing strategies for nevirapine initiation in young children. Further studies to establish age-appropriate threshold nevirapine concentration are warranted in young children to corroborate the role of therapeutic drug monitoring in predicting virological outcome.
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Affiliation(s)
- Bindu Parachalil Gopalan
- Division of Infectious Diseases, St. John’s Research Institute, St. John’s National Academy of Health Sciences, Bangalore, Karnataka, India
- The Institute Of Trans-Disciplinary Health Sciences and Technology (TDU), Bangalore, Karnataka, India
| | - Kayur Mehta
- Department of Pediatrics, St. John's Medical College Hospital, Bangalore, Karnataka, India
| | - Reena R. D'souza
- Division of Infectious Diseases, St. John’s Research Institute, St. John’s National Academy of Health Sciences, Bangalore, Karnataka, India
| | - Niharika Rajnala
- Division of Infectious Diseases, St. John’s Research Institute, St. John’s National Academy of Health Sciences, Bangalore, Karnataka, India
| | - Hemanth Kumar A. K.
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, Tamil Nadu, India
| | - Geetha Ramachandran
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, Tamil Nadu, India
| | - Anita Shet
- Division of Infectious Diseases, St. John’s Research Institute, St. John’s National Academy of Health Sciences, Bangalore, Karnataka, India
- * E-mail:
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Apostolova N, Blas-Garcia A, Galindo MJ, Esplugues JV. Efavirenz: What is known about the cellular mechanisms responsible for its adverse effects. Eur J Pharmacol 2017; 812:163-173. [PMID: 28690189 DOI: 10.1016/j.ejphar.2017.07.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 07/04/2017] [Accepted: 07/05/2017] [Indexed: 02/08/2023]
Abstract
The HIV infection remains an important health problem worldwide. However, due to the efficacy of combined antiretroviral therapy (cART), it has ceased to be a mortal condition, becoming a chronic disease instead. Efavirenz, the most prescribed non-nucleoside analogue reverse transcriptase inhibitor (NNRTI), has been a key component of cART since its commercialization in 1998. Though still a drug of choice in many countries, its primacy has been challenged by the arrival of newer antiretroviral agents with better toxicity profiles and treatment adherence. The major side effects related to EFV have been widely described in clinical studies, however the mechanisms that participate in their pathogenesis remain largely ununderstood. This review provides an insight into the cellular and molecular mechanisms responsible for the development of the most significant undesired effects induced by efavirenz, both short- and long-term, revealed by in vitro and in vivo experimental pharmacological research. Growing evidence implicates the drug in energy metabolism, mitochondrial function, and other cellular processes involved in stress responses including oxidative stress, inflammation and autophagy.
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Affiliation(s)
- Nadezda Apostolova
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia-Centro de Investigación Biomédica en Red-Enfermedades Hepáticas y Digestivas (CIBERehd), Valencia, Spain.
| | - Ana Blas-Garcia
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia-Centro de Investigación Biomédica en Red-Enfermedades Hepáticas y Digestivas (CIBERehd), Valencia, Spain
| | - Maria J Galindo
- Unidad de Enfermedades Infecciosas - Medicina Interna, Hospital Clínico Universitario de Valencia, Spain
| | - Juan V Esplugues
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia-Centro de Investigación Biomédica en Red-Enfermedades Hepáticas y Digestivas (CIBERehd), Valencia, Spain; FISABIO-Hospital Universitario Dr. Peset, Valencia, Spain
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Queiroz MAF, Laurentino RV, da Silva Graça Amoras E, Araújo MSMD, Gomes STM, Lima SS, Vallinoto ACR, de Oliveira Guimarães Ishak M, Ishak R, Machado LFA. The CYP2B6 G516T polymorphism influences CD4 + T-cell counts in HIV-positive patients receiving antiretroviral therapy in an ethnically diverse region of the Amazon. Int J Infect Dis 2016; 55:4-10. [PMID: 27940179 DOI: 10.1016/j.ijid.2016.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 11/30/2016] [Accepted: 12/02/2016] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES Cytochrome P450 (CYP) enzyme polymorphisms seem to significantly influence the variability of the responses to certain antiretroviral drugs and their toxicity levels. The objective of this study was to evaluate the influence of the CYP2B6 G516T polymorphism on hepatic, renal, immunological, and viral marker changes in HIV-1-positive patients receiving treatment in an ethnically diverse region of the Amazon. METHODS CYP2B6 G516T genotyping was performed by real-time PCR (RT-PCR) in samples from 185 patients. Urea, creatinine, aspartate aminotransferase (AST), alanine aminotransferase (ALT), CD4+/CD8+ T-cell counts, and HIV-1 plasma viral load were measured. RESULTS The polymorphic CYP2B6 G516T allele frequency was 0.36, which is different from the frequencies in other ethnic groups. The polymorphic genotype was associated with changes in the urea and ALT levels, although the median values were within the normal range. The TT genotype was also associated with significantly lower CD4+ T-cell counts in patients using efavirenz. CONCLUSIONS The CYP2B6 G516T polymorphism seems to affect the response to efavirenz treatment by reducing CD4+ T-cell counts in patients with a high degree of miscegenation who use this antiretroviral agent.
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Affiliation(s)
- Maria Alice Freitas Queiroz
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | - Rogério Valois Laurentino
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | - Ednelza da Silva Graça Amoras
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | | | - Samara Tatielle Monteiro Gomes
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | - Sandra Souza Lima
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | - Antonio Carlos Rosário Vallinoto
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | - Marluísa de Oliveira Guimarães Ishak
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | - Ricardo Ishak
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | - Luiz Fernando Almeida Machado
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil.
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Hui KH, Lee SS, Lam TN. Dose Optimization of Efavirenz Based on Individual CYP2B6 Polymorphisms in Chinese Patients Positive for HIV. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2016; 5:182-91. [PMID: 27299708 PMCID: PMC4846779 DOI: 10.1002/psp4.12067] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 01/29/2016] [Indexed: 02/05/2023]
Abstract
The purpose of this study was to investigate the impact of CYP2B6‐G516T polymorphisms on the pharmacokinetics (PKs) of efavirenz among the Chinese population and to propose doses for different genotypic populations that optimize therapeutic outcomes. Nonlinear mixed‐effect modeling was applied to describe PKs of efavirenz in Chinese patients with human immunodeficiency virus (HIV). Probabilities of successful treatment at different doses were obtained by simulations using the developed model to identify the optimal doses. The model was based on data from 163 individuals. Efavirenz clearance was found to be significantly influenced by CYP2B6‐G516T polymorphisms and body weight. The typical values of oral clearance were 10.2 L/h, 7.33 L/h, and 2.38 L/h and simulation results suggested that the optimal daily oral doses are 550 mg, 350 mg, and 100 mg for the GG, GT, and TT populations, respectively. The effect of CYP2B6‐G516T polymorphisms on efavirenz clearance was successfully quantified. Pharmacogenetics‐based dose individualization of efavirenz may optimize patient outcomes by promoting efficacy while minimizing central nervous system (CNS) side effects.
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Affiliation(s)
- K H Hui
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - S S Lee
- Stanley Ho Centre for Emerging Infectious Diseases, Shatin, New Territories, Hong Kong.,Department of Microbiology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - T N Lam
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
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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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Rufini S, Ciccacci C, Politi C, Giardina E, Novelli G, Borgiani P. Stevens-Johnson syndrome and toxic epidermal necrolysis: an update on pharmacogenetics studies in drug-induced severe skin reaction. Pharmacogenomics 2015; 16:1989-2002. [PMID: 26555663 DOI: 10.2217/pgs.15.128] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Stevens-Johnson syndrome and toxic epidermal necrolysis are severe, life-threatening drug reactions involving skin and membranes mucous, which are associated with significant morbidity and mortality and triggered, especially by drug exposure. Different studies have demonstrated that drug response is a multifactorial character and that the interindividual variability in this response depends on both environmental and genetic factors. The last ones have a relevant significance. In fact, the identification of new specific genetic markers involved in the response to drugs, will be of great utility to establish a more personalized therapeutic approach and to prevent the appearance of these adverse reactions. In this review, we summarize recent progresses in the Pharmacogenetics studies related to Stevens-Johnson syndrome/toxic epidermal necrolysis reporting the major genetic factors identified in the last years as associated with the disease and highlighting the use of some of these genomic variants in the clinical practice.
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Affiliation(s)
- Sara Rufini
- Department of Biomedicine & Prevention, Genetics Unit, University of Rome "Tor Vergata", Italy
| | - Cinzia Ciccacci
- Department of Biomedicine & Prevention, Genetics Unit, University of Rome "Tor Vergata", Italy
| | - Cristina Politi
- Department of Biomedicine & Prevention, Genetics Unit, University of Rome "Tor Vergata", Italy
| | - Emiliano Giardina
- Department of Biomedicine & Prevention, Genetics Unit, University of Rome "Tor Vergata", Italy.,Laboratory of Molecular Genetics UILDM, Fondazione Santa Lucia, Rome, Italy
| | - Giuseppe Novelli
- Department of Biomedicine & Prevention, Genetics Unit, University of Rome "Tor Vergata", Italy
| | - Paola Borgiani
- Department of Biomedicine & Prevention, Genetics Unit, University of Rome "Tor Vergata", Italy
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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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Apostolova N, Funes HA, Blas-Garcia A, Galindo MJ, Alvarez A, Esplugues JV. Efavirenz and the CNS: what we already know and questions that need to be answered. J Antimicrob Chemother 2015. [PMID: 26203180 DOI: 10.1093/jac/dkv183] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The NNRTI efavirenz has long been one of the most frequently employed antiretroviral drugs in the multidrug regimens used to treat HIV infection, in accordance with its well-demonstrated antiretroviral efficacy and favourable pharmacokinetics. However, growing concern about its adverse effects has sometimes led to efavirenz being replaced by other drugs in the initial treatment selection or to switching of therapy to efavirenz-free regimens in experienced patients. Neurological and neuropsychiatric reactions are the manifestations most frequently experienced by efavirenz-treated patients and range from transitory effects, such as nightmares, dizziness, insomnia, nervousness and lack of concentration, to more severe symptoms including depression, suicidal ideation or even psychosis. In addition, efavirenz has recently been associated with mild/moderate neurocognitive impairment, which is of specific relevance given that half of the patients receiving ART eventually suffer some form of HIV-associated neurocognitive disorder. The mechanisms responsible for efavirenz-induced neurotoxicity are unclear, although growing evidence points to disturbances in brain mitochondrial function and bioenergetics. This review offers a comprehensive overview of the current evidence on the interaction that efavirenz displays with the CNS, including the penetration and concentration of the drug in the brain. We discuss the prevalence, types and specificities of its side effects and recently uncovered cellular mechanisms that may be involved in their development.
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Affiliation(s)
- Nadezda Apostolova
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain Facultad de Ciencias de la Salud, Universitat Jaume I, Castellón de la Plana, Spain CIBERehd (Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas), Valencia, Spain
| | - Haryes A Funes
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain
| | - Ana Blas-Garcia
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain CIBERehd (Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas), Valencia, Spain FISABIO-Hospital Universitario Dr Peset, Valencia, Spain
| | - Maria J Galindo
- Unidad de Enfermedades Infecciosas-Medicina Interna, Hospital Clínico Universitario de Valencia, Valencia, Spain
| | - Angeles Alvarez
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain CIBERehd (Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas), Valencia, Spain
| | - Juan V Esplugues
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain CIBERehd (Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas), Valencia, Spain FISABIO-Hospital Universitario Dr Peset, Valencia, Spain
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Weber A, Szalai R, Sipeky C, Magyari L, Melegh M, Jaromi L, Matyas P, Duga B, Kovesdi E, Hadzsiev K, Melegh B. Increased prevalence of functional minor allele variants of drug metabolizing CYP2B6 and CYP2D6 genes in Roma population samples. Pharmacol Rep 2015; 67:460-4. [DOI: 10.1016/j.pharep.2014.11.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 11/04/2014] [Accepted: 11/13/2014] [Indexed: 01/11/2023]
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18
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Carr DF, Chaponda M, Cornejo Castro EM, Jorgensen AL, Khoo S, Van Oosterhout JJ, Dandara C, Kampira E, Ssali F, Munderi P, Lalloo DG, Heyderman RS, Pirmohamed M. CYP2B6 c.983T>C polymorphism is associated with nevirapine hypersensitivity in Malawian and Ugandan HIV populations. J Antimicrob Chemother 2014; 69:3329-34. [PMID: 25147095 PMCID: PMC4228781 DOI: 10.1093/jac/dku315] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Background Nevirapine, an NNRTI used in HIV treatment, can cause hypersensitivity reactions in 6%–10% of patients. In the most serious cases (1.3%) this can manifest as Stevens–Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN). Methods DNA samples were obtained and analysed from a total of 209 adult patients with nevirapine hypersensitivity (57 from a prospective cohort and 152 routine clinic patients) and compared with 463 control patients on nevirapine without any hypersensitivity. The case group included 70 patients with SJS/TEN. All individuals were genotyped for two SNPs in the CYP2B6 gene [c.516G>T (CYP2B6*9) and c.983T>C (CYP2B6*18)] using the TaqMan real-time genotyping platform. The replication cohort comprised 29 controls and 55 nevirapine hypersensitive patients, including 8 SJS/TEN cases. Results An association between the CYP2B6 c.983T>C polymorphism and nevirapine-induced SJS/TEN was observed. In the SJS/TEN group, 30% of individuals possessed at least one c.983T>C versus 16% in the tolerant group [P = 0.006; OR (95% CI) 2.24 (1.27–3.94)]. This association was not significant in the replication cohort [P = 0.075; OR (95% CI) 4.33 (0.80–23.57)]. Combined analysis resulted in an OR of 2.52 (95% CI 1.48–4.20; P = 0.0005) for the association of c.983T>C with SJS/TEN. No association was observed for c.983T>C with other hypersensitivity phenotypes and for CYP2B6 c.516G>T with any hypersensitivity phenotypes. Conclusions Our data show an association between the c.983T>C polymorphism and nevirapine-induced SJS/TEN. CYP2B6 c.983T>C has a frequency of 5%–10% in a variety of African populations, but is not observed in Caucasians, thus representing an ethnic-specific predisposing factor.
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Affiliation(s)
- Daniel F Carr
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK
| | - Mas Chaponda
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi
| | - Elena M Cornejo Castro
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK
| | | | - Saye Khoo
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK
| | - Joep J Van Oosterhout
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi Dignitas International, Zomba, Malawi
| | - Collet Dandara
- Division of Human Genetics, University of Cape Town, Cape Town, South Africa
| | - Elizabeth Kampira
- Division of Human Genetics, University of Cape Town, Cape Town, South Africa Department of Pathology, College of Medicine, Blantyre, Malawi
| | | | - Paula Munderi
- UVRI/MRC Uganda Research Unit on AIDS, Entebbe, Uganda
| | | | - Robert S Heyderman
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Malawi Liverpool School of Tropical Medicine, Liverpool, UK
| | - Munir Pirmohamed
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK
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Reynolds J, Heysell SK. Understanding pharmacokinetics to improve tuberculosis treatment outcome. Expert Opin Drug Metab Toxicol 2014; 10:813-23. [PMID: 24597717 DOI: 10.1517/17425255.2014.895813] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Tuberculosis (TB) remains the leading cause of death from a curable infectious disease; drug-resistant TB threatens to dismantle all prior gains in global control. Suboptimal circulating anti-TB drug concentrations can lead to lack of cure and acquired drug resistance. AREAS COVERED This review will introduce pharmacokinetic parameters for key anti-TB drugs, as well as the indications and limitations of measuring these parameters in clinical practice. Current and novel methodologies for delivering anti-TB pharmacokinetic-pharmacodynamic data are highlighted and gaps in operational research described. EXPERT OPINION Individual pharmacokinetic variability is commonplace, underappreciated and difficult to predict without therapeutic drug monitoring (TDM). Pharmacokinetic thresholds associated with poor TB treatment outcome in drug-susceptible TB have recently been described and may now guide the application of TDM, but require validation in a variety of settings and comorbidities. Dried blood spots for TDM and prepackaged multidrug plates for minimum inhibitory concentration testing will overcome barriers of accessibility and represent areas for innovation. Operationalizing pharmacokinetics has the potential to improve TB outcomes in the most difficult-to-treat forms of the disease such as multidrug resistance. Clinical studies in these areas are eagerly anticipated and we expect will better define the rational introduction of novel therapeutics.
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Affiliation(s)
- Jonathan Reynolds
- University of Virginia, School of Medicine , PO Box 801340, Charlottesville, VA 22908-1340 , USA
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20
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Lawn SD, Meintjes G, McIlleron H, Harries AD, Wood R. Management of HIV-associated tuberculosis in resource-limited settings: a state-of-the-art review. BMC Med 2013; 11:253. [PMID: 24295487 PMCID: PMC4220801 DOI: 10.1186/1741-7015-11-253] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 11/07/2013] [Indexed: 01/08/2023] Open
Abstract
The HIV-associated tuberculosis (TB) epidemic remains a huge challenge to public health in resource-limited settings. Reducing the nearly 0.5 million deaths that result each year has been identified as a key priority. Major progress has been made over the past 10 years in defining appropriate strategies and policy guidelines for early diagnosis and effective case management. Ascertainment of cases has been improved through a twofold strategy of provider-initiated HIV testing and counseling in TB patients and intensified TB case finding among those living with HIV. Outcomes of rifampicin-based TB treatment are greatly enhanced by concurrent co-trimoxazole prophylaxis and antiretroviral therapy (ART). ART reduces mortality across a spectrum of CD4 counts and randomized controlled trials have defined the optimum time to start ART. Good outcomes can be achieved when combining TB treatment with first-line ART, but use with second-line ART remains challenging due to pharmacokinetic drug interactions and cotoxicity. We review the frequency and spectrum of adverse drug reactions and immune reconstitution inflammatory syndrome (IRIS) resulting from combined treatment, and highlight the challenges of managing HIV-associated drug-resistant TB.
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Affiliation(s)
- Stephen D Lawn
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
- The Desmond Tutu HIV Centre, Institute for Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Graeme Meintjes
- Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Clinical Infectious Diseases Research Initiative, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Helen McIlleron
- Division of Clinical Pharmacology, Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Anthony D Harries
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
- International Union against Tuberculosis and Lung Disease (The Union), Paris, France
| | - Robin Wood
- The Desmond Tutu HIV Centre, Institute for Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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Micheli JE, Chinn LW, Shugarts SB, Patel A, Martin JN, Bangsberg DR, Kroetz DL. Measuring the overall genetic component of nevirapine pharmacokinetics and the role of selected polymorphisms: towards addressing the missing heritability in pharmacogenetic phenotypes? Pharmacogenet Genomics 2013; 23:591-6. [PMID: 23982262 PMCID: PMC4048019 DOI: 10.1097/fpc.0b013e32836533a5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Nevirapine is an important component of highly active antiretroviral therapy used in the treatment of HIV infection. There is a considerable variation in the pharmacokinetics of nevirapine and this variation can impact the efficacy and toxicity of nevirapine. Although some of this variation can be attributed to environmental factors, the degree to which heritability influences nevirapine pharmacokinetics is unknown. This study aims to estimate how much variation in nevirapine pharmacokinetics is due to genetic factors and to investigate the contribution of selected polymorphisms to this variability. METHODS Two doses of immediate-release nevirapine were administered to European (n=11) and African American (n=6) participants recruited from the Research in Access to Care in the Homeless cohort. A repeated drug administration method was then used to determine the relative genetic contribution (r(GC)) to variability in nevirapine AUC(0-6 h). Nevirapine plasma levels were quantified using LC/MS/MS. Patients were also genotyped for selected polymorphisms in candidate genes that may influence nevirapine pharmacokinetics. RESULTS A significant r(GC) for nevirapine AUC(0-6 h) was found in Europeans (P=0.02) and African Americans (P=0.01). A trend toward higher nevirapine AUC(0-6 h) for the CYP2B6 516TT (rs3745274; Q172H) genotype was observed in European Americans (P=0.19). CONCLUSION This study demonstrates that there is a significant genetic component to variability in nevirapine pharmacokinetics. Although genetic variants such as CYP2B6 polymorphisms attributed to some of this variation, these data suggest that there may be additional genetic factors that influence nevirapine pharmacokinetics.
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Affiliation(s)
- Janine E Micheli
- Departments of aBioengineering and Therapeutic Sciences bEpidemiology cMedicine dThe Institute for Human Genetics, University of California, San Francisco, California eRagon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Massachusetts General Hospital Center for Global Health, Harvard Medical School, Boston, Massachusetts, USA
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Echenique IA, Rich JD. EFV/FTC/TDF-associated hepatotoxicity: a case report and review. AIDS Patient Care STDS 2013; 27:493-7. [PMID: 23937548 DOI: 10.1089/apc.2013.0008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The fixed-dose combination efavirenz, emtricitabine, and tenofovir (EFV/FTC/TDF) is a first-line agent for the treatment of HIV. We report the case of a 40-year-old female with a history of HIV acquired through heterosexual contact who initiated EFV/FTC/TDF. Hepatitis B and C serologies were negative, CD4 cell count was 253 cells per cubic millimeter (15.8%), and HIV viral load was 67,373 copies per milliliter. Eight months later she developed transaminitis and severe right upper quadrant pain. Neither illicit drug abuse nor hepatotoxic medication such as acetaminophen was reported. After evaluation including negative acute viral hepatitis studies, EFV/FTC/TDF was discontinued; both her transaminitis and pain resolved. Hepatotoxicity is most often associated with efavirenz. Rarely, fulminant hepatic failure occurs. Efavirenz-related hepatotoxicity is thought to result from a cellular self-digestion process known as autophagy. This is the first report to our knowledge of EFV/FTC/TDF-related hepatotoxicity.
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Affiliation(s)
- Ignacio A. Echenique
- Division of Infectious Diseases, Feinberg School of Medicine of Northwestern University, Chicago, Illinois
| | - Josiah D. Rich
- Division of Infectious Diseases, The Miriam Hospital, Alpert Medical School of Brown University, Providence, Rhode Island
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Effects of rifampin-based antituberculosis therapy on plasma efavirenz concentrations in children vary by CYP2B6 genotype. AIDS 2013; 27:1933-40. [PMID: 24180002 DOI: 10.1097/qad.0b013e328360dbb4] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES An efavirenz-based antiretroviral therapy (ART) regimen is preferred for children more than 3 years of age with tuberculosis. However, rifampin, a key component of antituberculosis therapy, induces CYP2B6. An increased dose of efavirenz is recommended in adults weighing more than 50 kg who require rifampin, but there is scant information in children being treated for tuberculosis. DESIGN Plasma efavirenz concentrations were compared in 40 children during concomitant treatment for tuberculosis and HIV-1, after stopping rifampicin, and in a control group of children without tuberculosis. Associations with antituberculosis treatment, metabolizer genotype (based on CYP2B6 516G→T, 983T→C, and 15582C→T), weight, and time after dose were evaluated. RESULTS Compared to children with extensive metabolizer genotypes, efavirenz concentrations were increased 1.42-fold (95% confidence interval, CI 0.94–2.15) and 2.85-fold (95% CI 1.80–4.52) in children with intermediate and slow metabolizer genotypes, respectively. Concomitant antituberculosis treatment increased efavirenz concentrations 1.49-fold (95% CI 1.10–2.01) in children with slow metabolizer genotypes, but did not affect efavirenz concentrations in extensive or intermediate metabolizer genotypes. After adjustment for dose/kg, each kilogram of weight was associated with a 2.8% (95% CI 0.9–4.7) decrease in efavirenz concentrations. Despite higher milligram per kilogram doses, a higher proportion of children in the lowest weight band (10–13.9 kg) had efavirenz concentrations less than 1.0 mg/l than larger children. CONCLUSION Antituberculosis treatment was not associated with reduced efavirenz concentrations in children, which does not support increased efavirenz doses. Children with slow metabolizer genotype have increased efavirenz concentrations during antituberculosis treatment, likely due to isoniazid inhibiting enzymes involved in accessory metabolic pathways for efavirenz.
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Multiple genetic variants predict steady-state nevirapine clearance in HIV-infected Cambodians. Pharmacogenet Genomics 2013; 22:868-76. [PMID: 23104099 DOI: 10.1097/fpc.0b013e32835a5af2] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE In a previous analysis involving protocol ANRS 12154, interindividual variability in steady-state nevirapine clearance among HIV-infected Cambodians was partially explained by CYP2B6 516G→T (CYP2B6*6). Here, we examine whether additional genetic variants predict nevirapine clearance in this cohort. METHODS Analyses included Phnom Penh ESTHER (Ensemble pour une Solidarité Thérapeutique Hospitalière en Réseau) cohort participants who had consented for genetic testing. All participants were receiving nevirapine plus two nucleoside analogs. The mean individual nevirapine clearance estimates were derived from a population model developed on nevirapine concentrations at 18 and 36 months of therapy. Polymorphisms were assayed in ABCB1, CYP2A6, CYP2B6, CYP2C19, CYP3A4, CYP3A5, and NR1I2. RESULTS Of 198 assayed loci, 130 were polymorphic. Among 129 individuals with evaluable genetic data, nevirapine clearance ranged from 1.06 to 5.00 l/h in 128 individuals and was 7.81 l/h in one individual. In bivariate linear regression, CYP2B6 516G→T (CYP2B6*6) was associated with lower nevirapine clearances (P=3.5×10). In a multivariate linear regression model conditioned on CYP2B6 516G→T, independent associations were identified with CYP2B6 rs7251950, CYP2B6 rs2279343, and CYP3A4 rs2687116. The CYP3A4 association disappeared after censoring the outlier clearance value. A model that included CYP2B6 516G→T (P=1.0×10), rs7251950 (P=4.8×10), and rs2279343 (P=7.1×10) explained 11% of interindividual variability in nevirapine clearance. CONCLUSION Among HIV-infected Cambodians, several CYP2B6 polymorphisms were associated independently with steady-state nevirapine clearance. The prediction of nevirapine clearance was improved by considering several polymorphisms in combination.
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Vardhanabhuti S, Acosta EP, Ribaudo HJ, Severe P, Lalloo U, Kumarasamy N, Taulo F, Kabanda J, Oneko O, Ive P, Sambarey P, Chan ES, Hitti J, Hong F, McMahon D, Haas DW. Clinical and genetic determinants of plasma nevirapine exposure following an intrapartum dose to prevent mother-to-child HIV transmission. J Infect Dis 2013; 208:662-71. [PMID: 23687222 DOI: 10.1093/infdis/jit223] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
OBJECTIVE Nevirapine is metabolized by cytochrome P450 (CYP) 2B6 and CYP3A4. We characterized relationships between clinical parameters, human genetics, pharmacokinetics, and human immunodeficiency virus type 1 (HIV-1) drug resistance mutations in pregnant women following single-dose intrapartum nevirapine. METHODS In AIDS Clinical Trials Group study A5207, women received nevirapine at onset of labor and were randomly assigned to receive lamivudine/zidovudine, emtricitabine/tenofovir, or lopinavir/ritonavir for 7 or 21 days. Plasma nevirapine level was quantified on postpartum day 1 and on weeks 1, 3, and 5. We assayed 214 polymorphisms in CYP2B6 and other genes and evaluated associations with pharmacokinetic parameters, including elimination constant, time to protein-adjusted 50% inhibitory concentration (IC50), and week 5 nevirapine level below the quantification limit. RESULTS Among 301 women with evaluable pharmacokinetic and genotype data, lower body mass index and random assignment to receive lopinavir/ritonavir were associated with more rapid nevirapine elimination. Among those of African ancestry, longer time to IC50 was associated with CYP2B6 983T → C (P = .004) but not with CYP2B6 516G → T (P = .8). Among Indians, slower nevirapine elimination was associated with CYP2B6 516G → T (P = .04). Emergent resistance was infrequent and not associated with pharmacokinetics or CYP2B6 genotype. CONCLUSIONS The effects on plasma drug exposure following single-dose nevirapine may be greater for CYP2B6 983T → C than for 516G → T and are less pronounced than at steady state.
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Affiliation(s)
- Saran Vardhanabhuti
- Statistical Data Analysis Center, Harvard School of Public Health, Boston, Massachusetts, USA
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Li J, Menard V, Benish RL, Jurevic RJ, Guillemette C, Stoneking M, Zimmerman PA, Mehlotra RK. Worldwide variation in human drug-metabolism enzyme genes CYP2B6 and UGT2B7: implications for HIV/AIDS treatment. Pharmacogenomics 2012; 13:555-70. [PMID: 22462748 PMCID: PMC3390746 DOI: 10.2217/pgs.11.160] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
AIM Hepatic enzymes, CYP2B6 and UGT2B7 play a major role in the metabolism of the widely used antiretroviral drugs efavirenz, nevirapine and zidovudine. In the present study, we provide a view of UGT2B7 haplotype structure, and quantify the genetic diversity and differentiation at both CYP2B6 and UGT2B7 genes on a worldwide scale. MATERIALS & METHODS We genotyped one intronic and three promoter SNPs, and together with three nonsynonymous SNPs, inferred UGT2B7 alleles in north American (n = 326), west African (n = 133) and Papua New Guinean (n = 142) populations. We also included genotype data for five CYP2B6 and six UGT2B7 SNPs from an additional 12 worldwide populations (n = 629) analyzed in the 1000 Genomes Project. RESULTS We observed significant differences in certain SNP and allele frequencies of CYP2B6 and UGT2B7 among worldwide populations. Diversity values were higher for UGT2B7 than for CYP2B6, although there was more diversity between populations for CYP2B6. For both genes, most of the genetic variation was observed among individuals within populations, with the Papua New Guinean population showing the highest pairwise differentiation values for CYP2B6, and the Asian and European populations showing higher pairwise differentiation values for UGT2B7. CONCLUSION These new genetic distinctions provide additional insights for investigating differences in antiretroviral pharmacokinetics and therapy outcomes among ethnically and geographically diverse populations.
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Affiliation(s)
- Jing Li
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Vincent Menard
- Pharmacogenomics Laboratory, CHUQ Research Center & Faculty of Pharmacy, Laval University, QC, Canada
| | - Rebekah L Benish
- Center for Global Health & Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Richard J Jurevic
- Department of Biological Sciences, Case Western Reserve University School of Dental Medicine, Cleveland, OH, USA
| | - Chantal Guillemette
- Pharmacogenomics Laboratory, CHUQ Research Center & Faculty of Pharmacy, Laval University, QC, Canada
| | - Mark Stoneking
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Peter A Zimmerman
- Center for Global Health & Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Rajeev K Mehlotra
- Center for Global Health & Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
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McGraw J, Waller D. Cytochrome P450 variations in different ethnic populations. Expert Opin Drug Metab Toxicol 2012; 8:371-82. [PMID: 22288606 DOI: 10.1517/17425255.2012.657626] [Citation(s) in RCA: 183] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Variability of drug response is an important consideration in clinical medicine. A major determinant of drug response variability is hepatic cytochrome P450 oxidase (CYP450)-mediated drug metabolism. Advances in genetics permits genotyping large numbers of patients to identify single nucleotide polymorphisms (SNPs) which may result in variant CYP450 enzyme expression and/or activity. New SNPs with functional impacts are constantly being identified which further explain variability in CYP450 phenotype. AREAS COVERED The racial/ethnic distribution of selected CYP450 (CYP1A2, P2C8/9/19, 2D6 and 3A4/5) SNPs are reviewed with an emphasis on the agreement between genotype and phenotype. The reader will gain insight into the SNP distribution by racial/ethnic group and the corresponding relationship between important, highly prevalent, SNPs and their impact on metabolic phenotype. EXPERT OPINION Racial/ethnic differences in metabolic phenotype can be explained by differences in SNP distribution. However, overlap in substrate specificity, linkage disequilibrium and previously unidentified SNPs have made phenotypic characterization difficult for CYP3A4/5 and 2C8/9. Studies utilizing newly identified, highly prevalent, racially stratified SNPs and their impact on CYP isoform-specific metabolism will provide new answers.
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Affiliation(s)
- Joseph McGraw
- Concordia University Wisconsin, School of Pharmacy, 12800 N. Lakeshore Drive, Mequon, WI 53022, USA.
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28
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Pavlos R, Phillips EJ. Individualization of antiretroviral therapy. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2011; 5:1-17. [PMID: 23226059 PMCID: PMC3513193 DOI: 10.2147/pgpm.s15303] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Indexed: 12/22/2022]
Abstract
Antiretroviral therapy (ART) has evolved considerably over the last three decades. From the early days of monotherapy with high toxicities and pill burdens, through to larger pill burdens and more potent combination therapies, and finally, from 2005 and beyond where we now have the choice of low pill burdens and once-daily therapies. More convenient and less toxic regimens are also becoming available, even in resource-poor settings. An understanding of the individual variation in response to ART, both efficacy and toxicity, has evolved over this time. The strong association of the major histocompatibility class I allele HLA-B*5701 and abacavir hypersensitivity, and its translation and use in routine HIV clinical practice as a predictive marker with 100% negative predictive value, has been a success story and a notable example of the challenges and triumphs in bringing pharmacogenetics to the clinic. In real clinical practice, however, it is going to be the exception rather than the rule that individual biomarkers will definitively guide patient therapy. The need for individualized approaches to ART has been further increased by the importance of non-AIDS comorbidities in HIV clinical practice. In the future, the ideal utilization of the individualized approach to ART will likely consist of a combined approach using a combination of knowledge of drug, virus, and host (pharmacogenetic and pharmacoecologic [factors in the individual’s environment that may be dynamic over time]) information to guide the truly personalized prescription. This review will focus on our knowledge of the pharmacogenetics of the efficacy and toxicity of currently available antiretroviral agents and the current and potential utility of such information and approaches in present and future HIV clinical care.
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Affiliation(s)
- Rebecca Pavlos
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Western Australia, Australia
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Brown KC, Hosseinipour MC, Hoskins JM, Thirumaran RK, Tien HC, Weigel R, Tauzie J, Shumba I, Lamba JK, Schuetz EG, McLeod HL, Kashuba ADM, Corbett AH. Exploration of CYP450 and drug transporter genotypes and correlations with nevirapine exposure in Malawians. Pharmacogenomics 2011; 13:113-21. [PMID: 22111602 DOI: 10.2217/pgs.11.132] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
AIM Genetic polymorphisms have the potential to influence drug metabolism and vary among ethnic groups. This study evaluated the correlation of genetic polymorphisms with nevirapine pharmacokinetics exposure in Malawians. MATERIALS & METHODS CYP450 2B6, 2D6, 3A4 and 3A5, ABCB1 and constitutive androstane receptor and pregnane X receptor, were analyzed for polymorphisms in 26 subjects. RESULTS Allele frequencies (variant) were: CYP2B6 514G>T (0.31) CYP2D6*4 (0.02); CYP2D6*17 (0.35); CYP3A4*1B (0.77); CYP3A5*3 (0.25); ABCB1 2677G>T (0.0), ABCB1 3435C>T (0.21), NR1I3 13711152T>C (0.02), NR1I2 44477T>C (0.10), NR1I2 63396C>T (0.33), NR1I2 6-bp indel (del: 0.17). CYP2B6 516G>T (non-wild-type/wild-type) correlated with nevirapine pharmacokinetic parameters; geometric mean ratios (95% CI): 1.75 (1.27-2.40) for area under the concentration time curve (AUC)(0-12 h), 1.58 (1.03-2.42) for C(0), and 0.53 (0.31-0.91) for clearance. In a multivariable model, nevirapine AUC increased by 1.5% per year of age (p < 0.0001), CYP2B6 516 T allele increased AUC by 92% (p < 0.0001), and CYP3A5*3 decreased AUC by 31% (p = 0.0027). CONCLUSION Allele frequencies were similar to other sub-Saharan African populations. The T allele for CYP2B6 516 was significantly associated with nevirapine exposure.
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Affiliation(s)
- Kevin C Brown
- University of North Carolina at Chapel Hill, Eshelman School of Pharmacy, 3202 Kerr Hall, Chapel Hill, NC 27599-7569, USA
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Viljoen M, Karlsson MO, Meyers TM, Gous H, Dandara C, Rheeders M. Influence of CYP2B6 516G>T polymorphism and interoccasion variability (IOV) on the population pharmacokinetics of efavirenz in HIV-infected South African children. Eur J Clin Pharmacol 2011; 68:339-47. [PMID: 22057858 DOI: 10.1007/s00228-011-1148-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 10/14/2011] [Indexed: 01/11/2023]
Abstract
OBJECTIVE To investigate the influence of CYP2B6 516G>T polymorphism, as a covariate, and of interoccasion variability (IOV) on the oral clearance (CL/F) of efavirenz (EFV) in treatment-naïve black South African children over a period of 24 months post-antiretroviral therapy (ART) initiation. METHODS HIV-infected black children (n = 60, aged 3-16 years), with no prior exposure to ART, eligible to commence ART and attending an outpatient clinic were enrolled into this study. Blood samples were taken at mid-dose interval at 1, 3, 6, 12, 18 and 24 months post-ART initiation. EFV plasma samples were determined with an adapted and validated LC/MS/MS method. Genotyping of the CYP2B6 G516T single nucleotide polymorphism (SNP) was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). NONMEM was used for the population pharmacokinetic modelling. RESULTS EFV concentrations below 1 μg/mL accounted for 18% (116/649), EFV concentrations >4 μg/mL accounted for 29.5% (192/649) and concentrations within the therapeutic range (1-4 μg/mL) represented 52.5% (341/649) of all the samples determined. The covariates age, weight and CYP2B6 G516Tgenotype were included in the final model with population estimates for CL/F determined as 2.46, 4.60 and 7.33 L/h for the T/T, G/T and G/G genotype groups respectively. CONCLUSIONS The inclusion of both age and weight to predict accurate EFV CL values for the respective genotype groups within this paediatric population was required, whereas the addition of gender and body surface area did not improve the predictions. The importance of introducing IOV in a PK model for a longitudinal study with sparsely collected data was again highlighted by this investigation.
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Affiliation(s)
- M Viljoen
- Unit for Drug Research and Development, Division of Pharmacology, School of Pharmacy, North-West University, Potchefstroom, South Africa.
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Apostolova N, Gomez-Sucerquia LJ, Gortat A, Blas-Garcia A, Esplugues JV. Compromising mitochondrial function with the antiretroviral drug efavirenz induces cell survival-promoting autophagy. Hepatology 2011; 54:1009-19. [PMID: 21626526 DOI: 10.1002/hep.24459] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Accepted: 05/12/2011] [Indexed: 12/07/2022]
Abstract
UNLABELLED Hepatotoxicity is a very common side effect associated with the pharmacological treatment of human immunodeficiency virus (HIV) infection and its pathogenesis is poorly understood. Efavirenz (EFV) is the most widely used nonnucleoside reverse transcriptase inhibitor administered for the control of HIV and some of its toxic effects in hepatic cells have been recently shown to display features of mitochondrial dysfunction. Here we studied the activation of autophagy and, in particular, mitophagy, the main mitochondrial turnover mechanism, in human hepatic cells treated with clinically relevant concentrations of this drug. EFV-treated cells had altered mitochondria, characterized by a relative increase in mitochondrial mass and defective morphology. This was followed by induction of autophagy as shown by the presence of autophagic vacuoles and the presence of the specific autophagic marker proteins microtubule-associated protein 1A/1B light chain 3 and Beclin-1. Importantly, whereas moderate levels of EFV activated autophagy, higher concentrations led to blockage in the autophagic flux, a condition that promotes "autophagic stress" and produces severe cellular damage. Finally, pharmacological inhibition of autophagy exacerbated the deleterious effect of EFV on cell survival/proliferation promoting apoptosis, which suggests that autophagy acts as an adaptive mechanism of cell survival. CONCLUSION Clinical concentrations of EFV induce autophagy and, in particular, mitophagy in hepatic cells. Activation of this process promotes cell survival, but exceeding a certain threshold of mitochondrial dysfunction is associated with an autophagic overload or stress. This effect could be involved in the EFV-associated hepatotoxicity and may constitute a new mechanism implicated in the genesis of drug-induced liver damage.
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Affiliation(s)
- Nadezda Apostolova
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain.
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Swaminathan S, Ramachandran G, Agibothu Kupparam HK, Mahalingam V, Soundararajan L, Perumal Kannabiran B, Navaneethapandian PGD, Shah I, Karunaianandham R, Sikhamani R. Factors influencing plasma nevirapine levels: a study in HIV-infected children on generic antiretroviral treatment in India. J Antimicrob Chemother 2011; 66:1354-9. [PMID: 21393201 DOI: 10.1093/jac/dkr075] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Nevirapine is an important component of paediatric combination HIV therapy. Adequate drug exposure is necessary in order to achieve long-lasting viral suppression. OBJECTIVES To study the influence of age, drug dose and formulation type, nutritional status and CYP2B6 516G>T polymorphism on blood concentrations of nevirapine in children treated with generic antiretroviral drugs. METHODS A multicentre study was conducted at four sites in India. HIV-infected children receiving generic nevirapine-based fixed-dose combinations were recruited. Trough and 2 h nevirapine plasma concentrations were determined by HPLC. Characterization of the CYP2B6 gene polymorphism was performed using direct sequencing. Clinical and nutritional status was recorded. Groups were compared using the Mann-Whitney U-test and multivariable logistic regression analysis was performed to identify factors contributing to low drug levels. RESULTS Ninety-four children of median age 78 months were studied; 60% were undernourished or stunted. Stunted children had a significantly lower 2 h nevirapine concentration compared with non-stunted children (P < 0.05); there were no significant differences in trough concentrations between different nutritional groups. Nevirapine levels were significantly higher in children with TT compared with GG and GT CYP2B6 genotypes (P < 0.01). Children ≤ 3 years had a 3.2 (95% confidence interval 1.07-9.45) times higher risk of having sub-therapeutic nevirapine concentrations. CONCLUSIONS Nevirapine blood concentrations are affected by many factors, most notably age ≤ 3 years; a combination of young age, stunting and CYP2B6 GG or GT genotype could potentially result in sub-therapeutic nevirapine concentrations. Dosing recommendations for children should be reviewed in the light of these findings.
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Affiliation(s)
- Soumya Swaminathan
- Tuberculosis Research Centre (Indian Council of Medical Research), Chennai, India.
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CYP2B6 polymorphism and nonnucleoside reverse transcriptase inhibitor plasma concentrations in Chinese HIV-infected patients. Ther Drug Monit 2011; 32:573-8. [PMID: 20625352 DOI: 10.1097/ftd.0b013e3181ea953c] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The purpose of this study was to investigate the frequency of CYP2B6 polymorphisms and their influence on plasma concentrations of efavirenz and nevirapine in HIV-infected Chinese patients. After written informed consent, 159 patients were enrolled at Shanghai Public Health Clinical Center. Genotyping for 516 G>T, 785 A>G, 983 T>C, and 1459 T>C polymorphisms in CYP2B6, together with CYP3A4 -392 A>G, CYP3A5 6986 A>G, and ABCB1 (2677 G>T/A, 3435 C>T), were performed. Plasma efavirenz and nevirapine concentrations of 120 patients at steady state were assessed by high-performance liquid chromatography-mass spectrometry. The minor allele frequency for CYP2B6 516 G>T, 785 A>G, 983 T>C, and 1459 T>C was 0.16, 0.24, 0, and 0, respectively; and 0.07, 0.32, 0.15, and 0.35 for CYP3A4 -392 A>G, CYP3A5 6986 A>G, ABCB1 2677 G>T/A, and ABCB1 3435 C>T, respectively. Univariate analysis indicated associations between 516 G>T (P < 0.01) with efavirenz but not nevirapine plasma concentrations. None of other genetic variants was associated with plasma efavirenz or nevirapine concentrations. Although CYP2B6 516 G>T was associated with high plasma efavirenz concentrations, such an association was not evident with nevirapine in this Chinese patient population. CYP3A4 -392 A>G, CYP3A5 6986 A>G, and ABCB1 (2677 G>T/A, 3435 C>T) had no significant impact on plasma efavirenz or nevirapine concentrations.
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Yuan ZH, Liu Q, Zhang Y, Liu HX, Zhao J, Zhu P. CYP2B6 gene single nucleotide polymorphisms and leukemia susceptibility. Ann Hematol 2010; 90:293-9. [DOI: 10.1007/s00277-010-1085-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Accepted: 09/12/2010] [Indexed: 01/03/2023]
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Uttayamakul S, Likanonsakul S, Manosuthi W, Wichukchinda N, Kalambaheti T, Nakayama EE, Shioda T, Khusmith S. Effects of CYP2B6 G516T polymorphisms on plasma efavirenz and nevirapine levels when co-administered with rifampicin in HIV/TB co-infected Thai adults. AIDS Res Ther 2010; 7:8. [PMID: 20338069 PMCID: PMC2859392 DOI: 10.1186/1742-6405-7-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Accepted: 03/26/2010] [Indexed: 12/18/2022] Open
Abstract
Background Cytochrome P450 2B6 (CYP2B6) metabolizes efavirenz and nevirapine, the major core antiretroviral drugs for HIV in Thailand. Rifampicin, a critical component of tuberculosis (TB) therapy is a potent inducer of CYP enzyme activity. Polymorphisms of CYP2B6 and CYP3A4 are associated with altered activity of hepatic enzyme in the liver and pharmacokinetics resulting in treatment efficacy. This study aimed to investigate whether CYP2B6 or CYP3A4 polymorphisms had effects on plasma efavirenz and nevirapine concentrations when co-administered with rifampicin in HIV/TB co-infected Thai adults. Results We studied 124 rifampicin recipients with concurrent HIV-1/TB coinfection, receiving efavirenz (600 mg/day) (n = 65) or nevirapine (400 mg/day) (n = 59) based antiretroviral therapy (ART). The frequencies of GG, GT and TT genotypes of CYP2B6-G516T were 38.46%, 47.69% and 13.85% in efavirenz group and 44.07%, 52.54% and 3.39% in nevirapine group, respectively. The mean 12-hour post-dose plasma efavirenz concentration in patients with TT genotype at weeks 6 and 12 of ART and 1 month after rifampicin discontinuation (10.97 ± 2.32, 13.62 ± 4.21 and 8.48 ± 1.30 mg/L, respectively) were significantly higher than those with GT (3.43 ± 0.29, 3.35 ± 0.27 and 3.21 ± 0.22 mg/L, respectively) (p < 0.0001) or GG genotypes (2.88 ± 0.33, 2.45 ± 0.26 and 2.08 ± 0.16 mg/L, respectively) (p < 0.0001). Likewise, the mean 12-hour post-dose plasma nevirapine concentration in patients carrying TT genotype at weeks 6 and 12 of ART and 1 month after rifampicin discontinuation (14.09 ± 9.49, 7.94 ± 2.76 and 9.44 ± 0.17 mg/L, respectively) tended to be higher than those carrying GT (5.65 ± 0.54, 5.58 ± 0.48 and 7.03 ± 0.64 mg/L, respectively) or GG genotypes (5.42 ± 0.48, 5.34 ± 0.50 and 6.43 ± 0.64 mg/L, respectively) (p = 0.003, p = 0.409 and p = 0.448, respectively). Compared with the effects of CYP2B6-516TT genotype, we could observe only small effects of rifampicin on plasma efavirenz and nevirapine levels. After 12 weeks of both drug regimens, there was a trend towards higher percentage of patients with CYP2B6-TT genotype who achieved HIV-1 RNA levels <50 copies/mL compared to those with GT or GG genotypes. This is the first report to demonstrate the effects of CYP2B6 G516T polymorphisms on plasma efavirenz and nevirapine concentrations when co-administered with rifampicin in HIV/TB co-infected Thai adults. Conclusions CYP2B6-TT genotype had impact on plasma efavirenz and nevirapine concentrations, while rifampicin co-administration had only small effects.
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Bray J, Sludden J, Griffin MJ, Cole M, Verrill M, Jamieson D, Boddy AV. Influence of pharmacogenetics on response and toxicity in breast cancer patients treated with doxorubicin and cyclophosphamide. Br J Cancer 2010; 102:1003-9. [PMID: 20179710 PMCID: PMC2844036 DOI: 10.1038/sj.bjc.6605587] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background: Doxorubicin and cyclophosphamide (AC) therapy is an effective treatment for early-stage breast cancer. Doxorubicin is a substrate for ABCB1 and SLC22A16 transporters. Cyclophosphamide is a prodrug that requires oxidation to 4-hydroxycyclophosphamide, which yields a cytotoxic alkylating agent. The initial oxidation is catalysed by cytochrome P450 enzymes including CYP2B6, CYP2C9, CYP2C19 and CYP3A5. Polymorphic variants of the genes coding for these enzymes and transporters have been identified, which may influence the systemic pharmacology of the two drugs. It is not known whether this genetic variation has an impact on the efficacy or toxicity of AC therapy. Methods: Germ line DNA samples from 230 patients with breast cancer on AC therapy were genotyped for the following SNPs: ABCB1 C1236T, G2677T/A and C3435T, SLC22A16 A146G, T312C, T755C and T1226C, CYP2B6*2, *8, *9, *3, *4 and *5, CYP2C9*2 and *3, CYP3A5*3 and CYP2C19*2. Clinical data on survival, toxicity, demographics and pathology were collated. Results: A lower incidence of dose delay, indicative of less toxicity, was seen in carriers of the SLC22A16 A146G, T312C, T755C variants. In contrast, a higher incidence of dose delay was seen in carriers of the SLC22A16 1226C, CYP2B6*2 and CYP2B6*5 alleles. The ABCB1 2677A, CYP2B6*2, CYP 2B6*8, CYP 2B6*9, CYP 2B6*4 alleles were associated with a worse outcome. Conclusion: Variant alleles in the ABCB1, SLC22A16 and CYP2B6 genes are associated with response to AC therapy in the treatment of breast cancer.
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Affiliation(s)
- J Bray
- Northern Institute for Cancer Research, Medical School, Newcastle University, Newcastle upon Tyne, UK
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Kwara A, Ramachandran G, Swaminathan S. Dose adjustment of the non-nucleoside reverse transcriptase inhibitors during concurrent rifampicin-containing tuberculosis therapy: one size does not fit all. Expert Opin Drug Metab Toxicol 2010; 6:55-68. [PMID: 19968575 DOI: 10.1517/17425250903393752] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
IMPORTANCE OF THE FIELD HIV/tuberculosis (TB) co-infection is common and associated with high mortality. Simultaneous highly active antiretroviral therapy during TB treatment is associated with substantial survival benefit but drug-drug interactions complicate NNRTI dosing. AREAS COVERED IN THIS REVIEW We reviewed the impact of rifampicin-containing TB therapy on the NNRTIs pharmacokinetics and clinical outcome. PubMed database was searched from 1966 to July 2009 using the terms efavirenz, rifampicin, nevirapine, pharmacokinetics, pharmacogenetics, HIV, TB, CYP2B6, CYP3A4 and metabolism. References from identified articles and abstracts from meetings were also reviewed. WHAT THE READER WILL GAIN A comprehensive review of the literature on this subject including pharmacokinetic and clinical studies. Most studies were small, observational or underpowered to detect the true effect of rifampicin on NNRTI-based therapy. None of the studies were controlled for genetic factors and there were limited data on children. TAKE HOME MESSAGE There were insufficient data to make definitive recommendations about dose adjustment of the NNRTIs during rifampin-containing therapy. Current data suggest that the standard dose of efavirenz or nevirapine is adequate in most HIV/TB co-infected adults. However, more research is needed in pediatric populations as well as to define role of drug-gene interactions.
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Affiliation(s)
- Awewura Kwara
- Warren Alpert Medical School of Brown University and The Miriam Hospital, Providence, Rhode Island 02906, USA.
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Eyer F, Roberts DM, Buckley NA, Eddleston M, Thiermann H, Worek F, Eyer P. Extreme variability in the formation of chlorpyrifos oxon (CPO) in patients poisoned by chlorpyrifos (CPF). Biochem Pharmacol 2009; 78:531-7. [PMID: 19433070 PMCID: PMC2714474 DOI: 10.1016/j.bcp.2009.05.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 04/20/2009] [Accepted: 05/04/2009] [Indexed: 11/20/2022]
Abstract
Chlorpyrifos (CPF) is a pesticide that causes tens of thousands of deaths per year worldwide. Chlorpyrifos oxon (CPO) is the active metabolite of CPF that inhibits acetylcholinesterase. However, this presumed metabolite has escaped detection in human samples by conventional methods (HPLC, GC-MS, LC-MS) until now. A recently developed enzyme-based assay allowed the determination of CPO in the nanomolar range and was successfully employed to detect this metabolite. CPO and CPF were analysed in consecutive plasma samples of 74 patients with intentional CPF poisoning. A wide concentration range of CPO and CPF was observed and the ratio of CPO/CPF varied considerably between individuals and over time. The ratio increased during the course of poisoning from a mean of 0.005 in the first few hours after ingestion up to an apparent steady-state mean of 0.03 between 30 and 72 h. There was a hundred-fold variation in the ratio between samples and the interquartile range (between individuals) indicated over half the samples had a 5-fold or greater variation from the mean. The ratio was independent of the CPF concentration and the pralidoxime regimen. CPO was present in sufficient quantities to explain any observed acetylcholinesterase inhibitory activity. The effectiveness of pralidoxime in reactivating the inhibited acetylcholinesterase is strongly dependent on the CPO concentration. Differences in clinical outcomes and the response to antidotes in patients with acute poisoning may occur due to inter-individual variability in metabolism.
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Affiliation(s)
- Florian Eyer
- Toxicological Department of the 2nd Medical Clinic, Technische Universität München, Ismaninger Str. 22, D-81664 Munich, Germany
| | - Darren M. Roberts
- South Asian Clinical Toxicology Research Collaboration, and Burns, Trauma and Critical Care Research Centre, University of Queensland, Brisbane, Australia
| | - Nicholas A. Buckley
- South Asian Clinical Toxicology Research Collaboration, and Professorial Medical Unit, University of NSW, Sydney, Australia
| | - Michael Eddleston
- Scottish Poisons Information Bureau, Royal Infirmary, and Clinical Pharmacology Unit, University of Edinburgh, UK
| | - Horst Thiermann
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Franz Worek
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Peter Eyer
- Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig Maximilians University, Goethestr. 33, D-80336 Munich, Germany
- Corresponding author. Tel.: +49 89 2180 75722; fax: +49 89 2180 75701.
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