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Chotsiri P, Mahamar A, Diawara H, Fasinu PS, Diarra K, Sanogo K, Bousema T, Walker LA, Brown JM, Dicko A, Gosling R, Chen I, Tarning J. Population pharmacokinetics of primaquine and its metabolites in African males. Malar J 2024; 23:159. [PMID: 38773528 PMCID: PMC11106956 DOI: 10.1186/s12936-024-04979-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 05/09/2024] [Indexed: 05/24/2024] Open
Abstract
BACKGROUND Primaquine (PQ) is the prototype 8-aminoquinoline drug, a class which targets gametocytes and hypnozoites. The World Health Organization (WHO) recommends adding a single low dose of primaquine to the standard artemisinin-based combination therapy (ACT) in order to block malaria transmission in regions with low malaria transmission. However, the haemolytic toxicity is a major adverse outcome of primaquine in glucose-6-phosphate dehydrogenase (G6PD)-deficient subjects. This study aimed to characterize the pharmacokinetic properties of primaquine and its major metabolites in G6PD-deficient subjects. METHODS A single low-dose of primaquine (0.4-0.5 mg/kg) was administered in twenty-eight African males. Venous and capillary plasma were sampled up to 24 h after the drug administration. Haemoglobin levels were observed up to 28 days after drug administration. Only PQ, carboxy-primaquine (CPQ), and primaquine carbamoyl-glucuronide (PQCG) were present in plasma samples and measured using liquid chromatography mass spectrometry. Drug and metabolites' pharmacokinetic properties were investigated using nonlinear mixed-effects modelling. RESULTS Population pharmacokinetic properties of PQ, CPQ, and PQCG can be described by one-compartment disposition kinetics with a transit-absorption model. Body weight was implemented as an allometric function on the clearance and volume parameters for all compounds. None of the covariates significantly affected the pharmacokinetic parameters. No significant correlations were detected between the exposures of the measured compounds and the change in haemoglobin or methaemoglobin levels. There was no significant haemoglobin drop in the G6PD-deficient patients after administration of a single low dose of PQ. CONCLUSIONS A single low-dose of PQ was haematologically safe in this population of G6PD-normal and G6PD-deficient African males without malaria. Trial registration NCT02535767.
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Affiliation(s)
- Palang Chotsiri
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand
| | - Almahamoudou Mahamar
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Halimatou Diawara
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Pius S Fasinu
- Department of Pharmacology & Toxicology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Kalifa Diarra
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Koualy Sanogo
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Larry A Walker
- National Center for Natural Products Research, The University of Mississippi, University, MS, USA
| | - Joelle M Brown
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA
| | - Alassane Dicko
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Roly Gosling
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
- Malaria Elimination Initiative, University of California, San Francisco, CA, USA
| | - Ingrid Chen
- Malaria Elimination Initiative, University of California, San Francisco, CA, USA
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford University, Oxford, UK.
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Fasinu PS, Wilborn TW. Pharmacology education in the medical curriculum: Challenges and opportunities for improvement. Pharmacol Res Perspect 2024; 12:e1178. [PMID: 38361337 PMCID: PMC10869893 DOI: 10.1002/prp2.1178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/19/2024] [Accepted: 01/26/2024] [Indexed: 02/17/2024] Open
Abstract
The knowledge and application of pharmacology is essential for safe prescribing and administration of drugs. In this narrative review, the challenges to pharmacology education in the medical curricula were broadly identified to include issues around content and pedagogies. The increasing number of approved drugs and drug targets, expanding field of pharmacology and the often-changing treatment guidelines and board-defined competencies can make pharmacology education in the medical curriculum daunting. There has been a consensus around the deployment of innovative medical curricula with emphasis on vertical and horizontal integration. This strategy, effective as it has been, presents new challenges to pharmacology education. As a discipline often perceived by students to be hard-to-learn, the future of pharmacology education must include heavy reliance on active learning strategies. The continuing utilization of problem-based, team-based and case-based learning can be complemented with personalized learning which aims to identify the learning gaps in individual students. Technology-inspired student engagement can foster pharmacology learning and retention. Early exposure to pharmacology from premedical preparation through an enduring across-the-level integration can be an effective way to enhance pharmacology learning in the medical curricula.
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Affiliation(s)
- Pius S. Fasinu
- Department of Pharmacology & Toxicology, Heersink School of MedicineThe University of Alabama at BirminghamBirminghamAlabamaUSA
| | - Teresa W. Wilborn
- Department of Pharmacology & Toxicology, Heersink School of MedicineThe University of Alabama at BirminghamBirminghamAlabamaUSA
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Oueijan RI, Hill OR, Ahiawodzi PD, Fasinu PS, Thompson DK. Rare Heterogeneous Adverse Events Associated with mRNA-Based COVID-19 Vaccines: A Systematic Review. Medicines 2022; 9:medicines9080043. [PMID: 36005648 PMCID: PMC9416135 DOI: 10.3390/medicines9080043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/28/2022] [Accepted: 08/08/2022] [Indexed: 11/17/2022]
Abstract
Background: Since the successful development, approval, and administration of vaccines against SARS-CoV-2, the causative agent of COVID-19, there have been reports in the published literature, passive surveillance systems, and other pharmacovigilance platforms of a broad spectrum of adverse events following COVID-19 vaccination. A comprehensive review of the more serious adverse events associated with the Pfizer-BioNTech and Moderna mRNA vaccines is warranted, given the massive number of vaccine doses administered worldwide and the novel mechanism of action of these mRNA vaccines in the healthcare industry. Methods: A systematic review of the literature was conducted to identify relevant studies that have reported mRNA COVID-19 vaccine-related adverse events. Results: Serious and severe adverse events following mRNA COVID-19 vaccinations are rare. While a definitive causal relationship was not established in most cases, important adverse events associated with post-vaccination included rare and non-fatal myocarditis and pericarditis in younger vaccine recipients, thrombocytopenia, neurological effects such as seizures and orofacial events, skin reactions, and allergic hypersensitivities. Conclusions: As a relatively new set of vaccines already administered to billions of people, COVID-19 mRNA-based vaccines are generally safe and efficacious. Further studies on long-term adverse events and other unpredictable reactions in close proximity to mRNA vaccination are required.
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Affiliation(s)
- Rana I. Oueijan
- School of Pharmacy, College of Pharmacy and Health Sciences, Campbell University, Buies Creek, NC 27501, USA
| | - Olivia R. Hill
- School of Pharmacy, College of Pharmacy and Health Sciences, Campbell University, Buies Creek, NC 27501, USA
| | - Peter D. Ahiawodzi
- Department of Public Health, College of Pharmacy and Health Sciences, Campbell University, Buies Creek, NC 27501, USA
| | - Pius S. Fasinu
- Department of Pharmacology & Toxicology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Dorothea K. Thompson
- Department of Pharmaceutical and Clinical Sciences, College of Pharmacy and Health Sciences, Campbell University, Buies Creek, NC 27501, USA
- Correspondence: ; Tel.: +1-910-893-7463
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Le TT, McGrath SR, Fasinu PS. Herb-drug Interactions in Neuropsychiatric Pharmacotherapy - A Review of Clinically Relevant Findings. Curr Neuropharmacol 2022; 20:1736-1751. [PMID: 34370637 PMCID: PMC9881059 DOI: 10.2174/1570159x19666210809100357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/23/2021] [Accepted: 08/04/2021] [Indexed: 11/22/2022] Open
Abstract
The management of neuropsychiatric disorders relies heavily on pharmacotherapy. The use of herbal products as complimentary medicine, often concomitantly, is common among patients taking prescription neuropsychiatric drugs. Herb-drug interaction, a clinical consequence of this practice, may jeopardize the success of pharmacotherapy in neuropsychiatry. Besides the wellknown ability of phytochemicals to inhibit and/or induce drug-metabolizing enzymes and transport proteins, several phytoconstituents are capable of exerting pharmacological effects on the central nervous system. This study reviewed the relevant literature and identified 13 commonly used herbal products - celery, echinacea, ginkgo, ginseng, hydroxycut, kava, kratom, moringa, piperine, rhodiola, St. John's wort, terminalia/commiphora ayurvedic mixture and valerian - which have shown clinically relevant interactions with prescription drugs used in the management of neuropsychiatric disorders. The consequent pharmacokinetic and pharmacodynamic interactions with orthodox medications often result in deleterious clinical consequences. This underscores the importance of caution in herb-drug co-medication.
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Affiliation(s)
- Tram T. Le
- School of Pharmacy, College of Pharmacy and Health Sciences, Campbell University, Buies Creek, NC, 27501, USA;
| | - Sarah R. McGrath
- School of Pharmacy, College of Pharmacy and Health Sciences, Campbell University, Buies Creek, NC, 27501, USA;
| | - Pius S. Fasinu
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA,Address correspondence to this author at the Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA; Tel/Fax: +1 205 934 4565; E-mail:
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5
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Khan W, Wang YH, Chaurasiya ND, Nanayakkara NPD, Herath HMB, Harrison KA, Dale G, Stanford DA, Dahl EP, McChesney JD, Gul W, ElSohly MA, Khan SI, Fasinu PS, Khan IA, Tekwani BL, Walker LA. Comparative single dose pharmacokinetics and metabolism of racemic primaquine and its enantiomers in human volunteers. Drug Metab Pharmacokinet 2022; 45:100463. [PMID: 35709685 PMCID: PMC9789533 DOI: 10.1016/j.dmpk.2022.100463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/14/2022] [Accepted: 04/25/2022] [Indexed: 12/26/2022]
Abstract
Primaquine (PQ) is a racemic drug used in treatment of malaria for six decades. Recent studies suggest that the two enantiomers of PQ are differentially metabolized in animals, and this results in different pharmacological and toxicological profiles. The current study characterizes the pharmacokinetic (PK) properties, metabolism and tolerability of the individual enantiomers of PQ in healthy human volunteers with normal glucose-6-phosphate dehydrogenase (G6PD) activity. Two cohorts (at two dose levels), each with 18 subjects, participated in three study arms in a crossover fashion: a single dose of the (-)-R enantiomer (RPQ), a single dose of the (+)-S enantiomer (SPQ), and a single dose of racemic PQ (RSPQ). PQ and its key metabolites carboxyprimaquine (cPQ) and PQ-N-carbamoyl glucuronide (PQ-N-CG) were analyzed. Clear differences were observed in PK and metabolism of the two enantiomers. Relative PQ exposure was higher with SPQ as compared to RPQ. PQ maximum plasma concentration (Cmax) and area under the plasma concentration-time curve were higher for SPQ, while the apparent volume of distribution and total body clearance were higher for RPQ. Metabolism of the two enantiomers showed dramatic differences: plasma PQ-N-CG was derived solely from SPQ, while RPQ was much more efficiently converted to cPQ than was SPQ. Cmax of cPQ and PQ-N-CG were 10 and 2 times higher, respectively, than the parent drugs. The study demonstrates that the PK properties of PQ enantiomers show clear differences, and metabolism is highly enantioselective. Such differences in metabolism suggest potentially distinct toxicity profiles in multi-dose regimens, especially in G6PD-deficient subjects.
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Affiliation(s)
- Washim Khan
- National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA
| | - Yan-Hong Wang
- National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA
| | - Narayan D. Chaurasiya
- Department of Infectious Diseases, Division of Drug Discovery, Southern Research Institute, Birmingham, AL, 35205, USA
| | - NP Dhammika Nanayakkara
- National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA
| | - HM Bandara Herath
- National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA
| | - Kerri A. Harrison
- National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA
| | - Gray Dale
- National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA
| | - Donald A. Stanford
- National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA
| | - Eric P. Dahl
- National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA
| | | | - Waseem Gul
- ElSohly Laboratories, Inc., Oxford, MS, 38655, USA
| | - Mahmoud A. ElSohly
- National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA,Pharmaceutics and Drug Delivery, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA,ElSohly Laboratories, Inc., Oxford, MS, 38655, USA
| | - Shabana I. Khan
- National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA
| | - Pius S. Fasinu
- Department of Pharmacology & Toxicology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Ikhlas A. Khan
- National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA,Departments of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | - Babu L. Tekwani
- Department of Infectious Diseases, Division of Drug Discovery, Southern Research Institute, Birmingham, AL, 35205, USA,Corresponding author. (B.L. Tekwani)
| | - Larry A. Walker
- National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA,Corresponding author. (L.A. Walker)
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Fasinu PS, Okoye FBC, Abiodun OO, Kamdem RST, Ogbole OO. Editorial: Fungal Bioactive Metabolites of Pharmacological Relevance. Front Pharmacol 2022; 13:912068. [PMID: 35754512 PMCID: PMC9213805 DOI: 10.3389/fphar.2022.912068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 05/10/2022] [Indexed: 11/22/2022] Open
Affiliation(s)
- Pius S Fasinu
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Festus B C Okoye
- Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University Awka, Awka, Nigeria
| | - Oyindamola O Abiodun
- Department of Pharmacology and Therapeutics, University of Ibadan, Ibadan, Nigeria
| | - Ramsay S T Kamdem
- Institut für Organische and Analytische Chemie, Universität Bremen, Bremen, Germany
| | - Omonike O Ogbole
- Department of Pharmacognosy, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria
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Fasinu PS, Chaurasiya ND, Dhammika Nanayakkara NP, Wang Y, Bandara Herath HMT, Avula B, McChesney JD, Jollow D, Walker LA, Tekwani BL. Comparative pharmacokinetics and tissue distribution of primaquine enantiomers in mice. Malar J 2022; 21:33. [PMID: 35123453 PMCID: PMC8817607 DOI: 10.1186/s12936-022-04054-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 01/18/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Primaquine (PQ) has been used for the radical cure of relapsing Plasmodium vivax malaria for more than 60 years. PQ is also recommended for prophylaxis and prevention of transmission of Plasmodium falciparum. However, clinical utility of PQ has been limited due to toxicity in individuals with genetic deficiencies in glucose 6-phosphate dehydrogenase (G6PD). PQ is currently approved for clinical use as a racemic mixture. Recent studies in animals as well as humans have established differential pharmacological and toxicological properties of the two enantiomers of PQ. This has been attributed to differential metabolism and pharmacokinetics of individual PQ enantiomers. The aim of the current study is to evaluate the comparative pharmacokinetics (PK), tissue distribution and metabolic profiles of the individual enantiomers in mice.
Methods
Two groups of 21 male Albino ND4 Swiss mice were dosed orally with 45 mg/kg of S-(+)-PQ and R-(−)PQ respectively. Each of the enantiomers was comprised of a 50:50 mixture of 12C- and 13C- stable isotope labelled species (at 6 carbons on the benzene ring of the quinoline core). Three mice were euthanized from each group at different time points (at 0, 0.5, 1, 2, 4, 8, 24 h) and blood was collected by terminal cardiac bleed. Liver, spleen, lungs, kidneys and brain were removed, extracted and analysed using UPLC/MS. The metabolites were profiled by tandem mass (MS/MS) fragmentation profile and fragments with 12C–13C twin peaks. Non-compartmental analysis was performed using the Phoenix WinNonLin PK software module.
Results
The plasma AUC0-last (µg h/mL) (1.6 vs. 0.6), T1/2 (h) (1.9 vs. 0.45), and Tmax (h) (1 vs. 0.5) were greater for SPQ as compared to RPQ. Generally, the concentration of SPQ was higher in all tissues. At Tmax, (0.5–1 h in all tissues), the level of SPQ was 3 times that of RPQ in the liver. Measured Cmax of SPQ and RPQ in the liver were about 100 and 40 times the Cmax values in plasma, respectively. Similar observations were recorded in other tissues where the concentration of SPQ was higher compared to RPQ (2× in the spleen, 6× in the kidneys, and 49× in the lungs) than in the plasma. CPQ, the major metabolite, was preferentially generated from RPQ, with higher levels in all tissues (> 10× in the liver, and 3.5× in the plasma) than from SPQ. The PQ-o-quinone was preferentially formed from the SPQ (> 4× compared to RPQ), with higher concentrations in the liver.
Conclusion
These studies show that in mice, PQ enantiomers are differentially biodistributed and metabolized, which may contribute to differential pharmacologic and toxicity profiles of PQ enantiomers. The findings on higher levels of PQ-o-quinone in liver and RBCs compared to plasma and preferential generation of this metabolite from SPQ are consistent with the higher anti-malarial efficacy of SPQ observed in the mouse causal prophylaxis test, and higher haemolytic toxicity in the humanized mouse model of G6PD deficiency. Potential relevance of these findings to clinical use of racemic PQ and other 8-aminoquinolines vis-à-vis need for further clinical evaluation of individual enantiomers are discussed.
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Jefferson A, Smith A, Fasinu PS, Thompson DK. Sexually Transmitted Neisseria gonorrhoeae Infections-Update on Drug Treatment and Vaccine Development. Medicines (Basel) 2021; 8:medicines8020011. [PMID: 33562607 PMCID: PMC7914478 DOI: 10.3390/medicines8020011] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/17/2021] [Accepted: 02/03/2021] [Indexed: 12/15/2022]
Abstract
Background: Sexually transmitted gonorrhea, caused by the Gram-negative diplococcus Neisseria gonorrhoeae, continues to be a serious global health challenge despite efforts to eradicate it. Multidrug resistance among clinical N. gonorrhoeae isolates has limited treatment options, and attempts to develop vaccines have not been successful. Methods: A search of published literature was conducted, and information extracted to provide an update on the status of therapeutics and vaccine development for gonorrheal infection. Results: Recommended pharmacological treatment for gonorrhea has changed multiple times due to increasing acquisition of resistance to existing antibiotics by N. gonorrhoeae. Only broad-spectrum cephalosporin-based combination therapies are currently recommended for treatment of uncomplicated urogenital and anorectal gonococcal infections. With the reported emergence of ceftriaxone resistance, successful strategies addressing the global burden of gonorrhea must include vaccination. Century-old efforts at developing an effective vaccine against gonorrhea, leading to only four clinical trials, have not yielded any successful vaccine. Conclusions: While it is important to continue to explore new drugs for the treatment of gonorrhea, the historical trend of resistance acquisition suggests that any long-term strategy should include vaccine development. Advanced technologies in proteomics and in silico approaches to vaccine target identification may provide templates for future success.
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Affiliation(s)
- Amber Jefferson
- School of Pharmacy, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC 27506, USA; (A.J.); (A.S.)
| | - Amanda Smith
- School of Pharmacy, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC 27506, USA; (A.J.); (A.S.)
| | - Pius S. Fasinu
- Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC 27506, USA;
| | - Dorothea K. Thompson
- Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC 27506, USA;
- Correspondence: ; Tel.: +1-910-893-7463
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Khan W, Wang YH, Nanayakkara NPD, Herath HMTB, Catchings Z, Khan S, Fasinu PS, ElSohly MA, McChesney JD, Khan IA, Chaurasiya ND, Tekwani BL, Walker LA. Quantitative determination of primaquine-5,6-ortho-quinone and carboxyprimaquine-5,6-ortho-quinone in human erythrocytes by UHPLC-MS/MS. J Chromatogr B Analyt Technol Biomed Life Sci 2020; 1163:122510. [PMID: 33387859 DOI: 10.1016/j.jchromb.2020.122510] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 12/08/2020] [Accepted: 12/15/2020] [Indexed: 01/28/2023]
Abstract
The antimalarial drug primaquine (PQ) causes methemoglobinemia and hemolysis in individuals with a genetic deficiency of glucose 6-phosphate dehydrogenase. Reactive oxygen species (ROS) generated by redox cycling of the metabolite primaquine-5,6-orthoquinone (POQ) in erythrocytes has been attributed to be responsible for the toxicity of PQ. Carboxyprimaquine (CPQ), the major human plasma metabolite of PQ, can also form the analogous carboxyprimaquine-5,6-orthoquinone (CPOQ) metabolite, which can also generate ROS in erythrocytes by redox cycling, thus contributing to the hematotoxicity of this drug. In order to study these pathways and characterize such effects in vivo, methods are needed for characterization and quantification of POQ and CPOQ in human erythrocytes. The purpose of this work was to develop a validated method for the quantitative determination of CPOQ and POQ metabolites in human erythrocytes, suitable for clinical studies of PQ metabolism. Several liquid-liquid extraction methods using different organic solvents had been investigated. The solvent mixture of water-methanol-acetonitrile (9:9:5, v/v) was shown to yield the best results for the two analytes. Chromatographic analysis of POQ and CPOQ in human erythrocytes was achieved on a high strength silica (HSS) column and gradient elution (water and acetonitrile, both containing 0.1% formic acid) by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). Quantitative estimation of POQ and CPOQ was executed by monitoring ion pairs of m/z 260.23 > 175.03 and m/z 275.19 > 175.04, respectively. The method, which was validated for precision, accuracy, selectivity, and linearity, was successfully applied for the quantitative determination of POQ and CPOQ, the key metabolites of PQ in human erythrocytes in PQ clinical study.
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Affiliation(s)
- Washim Khan
- National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA
| | - Yan-Hong Wang
- National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA.
| | - N P Dhammika Nanayakkara
- National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA
| | - H M T Bandara Herath
- National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA
| | - Zachara Catchings
- National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA
| | - Shabana Khan
- National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA
| | - Pius S Fasinu
- Department of Pharmaceutical Sciences, Campbell University, Buies Creek, NC 27506, USA
| | - Mahmoud A ElSohly
- National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA; ElSohly Laboratories, Inc., Oxford, MS 38655, USA
| | | | - Ikhlas A Khan
- National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA; Department of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, University, MS 38677, USA
| | - Narayan D Chaurasiya
- Department of Infectious Diseases, Division of Drug Discovery, Southern Research Institute, Birmingham, AL 35205, USA
| | - Babu L Tekwani
- Department of Infectious Diseases, Division of Drug Discovery, Southern Research Institute, Birmingham, AL 35205, USA
| | - Larry A Walker
- National Center for Natural Products Research, The University of Mississippi, University, MS 38677, USA.
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Harwell V, Fasinu PS. Pitolisant and Other Histamine-3 Receptor Antagonists-An Update on Therapeutic Potentials and Clinical Prospects. Medicines (Basel) 2020; 7:medicines7090055. [PMID: 32882898 PMCID: PMC7554886 DOI: 10.3390/medicines7090055] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/27/2020] [Accepted: 08/27/2020] [Indexed: 12/13/2022]
Abstract
Background: Besides its well-known role as a peripheral chemical mediator of immune, vascular, and cellular responses, histamine plays major roles in the central nervous system, particularly in the mediation of arousal and cognition-enhancement. These central effects are mediated by the histamine-3 auto receptors, the modulation of which is thought to be beneficial for the treatment of disorders that impair cognition or manifest with excessive daytime sleepiness. Methods: A database search of PubMed, Google Scholar, and clinicaltrials.gov was performed in June 2020. Full-text articles were screened and reviewed to provide an update on pitolisant and other histamine-3 receptor antagonists. Results: A new class of drugs—histamine-3 receptor antagonists—has emerged with the approval of pitolisant for the treatment of narcolepsy with or without cataplexy. At the recommended dose, pitolisant is well tolerated and effective. It has also been evaluated for potential therapeutic benefit in Parkinson disease, epilepsy, attention deficit hyperactivity disorder, Alzheimer’s disease, and dementia. Limited studies have shown pitolisant to lack abuse potential which will be a major advantage over existing drug options for narcolepsy. Several histamine-3 receptor antagonists are currently in development for a variety of clinical indications. Conclusions: Although limited clinical studies have been conducted on this new class of drugs, the reviewed literature showed promising results for future additions to the clinical indications of pitolisant, and the expansion of the list of approved drugs in this class for a variety of indications.
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Abstract
One of the most consequential risks associated with the concomitant use of herbal products and chemotherapeutic agents is herb-drug interactions. The risk is higher in patients with chronic conditions taking multiple medications. Herb-drug interaction is particularly undesirable in cancer management because of the precipitous dose-effect relationship and toxicity of chemotherapeutic agents. The most common mechanism of herb-drug interaction is the herbal-mediated inhibition and/or induction of drug-metabolizing enzymes (DME) and/or transport proteins leading to the alteration in the pharmacokinetic disposition of the victim drug. Most mechanistic research has focused on laboratory-based studies, determining the effects of herbal products on DMEs and extrapolating findings to predict clinical relevance; however, not all DME/transporter protein inhibition/induction results in clinical herb-drug interaction. This study reviews relevant literature and identified six herbal products namely echinacea, garlic, ginseng, grapefruit juice, milk thistle, and St John's wort, which have shown interactions with chemotherapeutic agents in humans. This focus on clinically significant herb-drug interaction, should be of interest to the public including practitioners, researchers, and consumers of cancer chemotherapy.
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Affiliation(s)
- Pius S Fasinu
- Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC, United States
| | - Gloria K Rapp
- Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC, United States
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12
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Kustos SA, Fasinu PS. Direct-Acting Oral Anticoagulants and Their Reversal Agents-An Update. Medicines (Basel) 2019; 6:medicines6040103. [PMID: 31618893 PMCID: PMC6963825 DOI: 10.3390/medicines6040103] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 10/10/2019] [Accepted: 10/14/2019] [Indexed: 12/13/2022]
Abstract
Background: Over the last ten years, a new class of drugs, known as the direct-acting oral anticoagulants (DOACs), have emerged at the forefront of anticoagulation therapy. Like the older generation anticoagulants, DOACs require specific reversal agents in cases of life-threatening bleeding or the need for high-risk surgery. Methods: Published literature was searched, and information extracted to provide an update on DOACS and their reversal agents. Results: The DOACs include the direct thrombin inhibitor—dabigatran, and the factor Xa inhibitors—rivaroxaban, apixaban, edoxaban, and betrixaban. These DOACs all have a rapid onset of action and each has a predictable therapeutic response requiring no monitoring, unlike the older anticoagulants, such as warfarin. Two reversal agents have been approved within the last five years: idarucizumab for the reversal of dabigatran, and andexanet alfa for the reversal of rivaroxaban and apixaban. Additionally, ciraparantag, a potential “universal” reversal agent, is currently under clinical development. Conclusions: A new generation of anticoagulants, the DOACs, and their reversal agents, are gaining prominence in clinical practice, having demonstrated superior efficacy and safety profiles. They are poised to replace traditional anticoagulants including warfarin.
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Affiliation(s)
- Stephanie A Kustos
- Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC 27506, USA.
| | - Pius S Fasinu
- Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC 27506, USA.
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13
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Sá JM, Kaslow SR, Moraes Barros RR, Brazeau NF, Parobek CM, Tao D, Salzman RE, Gibson TJ, Velmurugan S, Krause MA, Melendez-Muniz V, Kite WA, Han PK, Eastman RT, Kim A, Kessler EG, Abebe Y, James ER, Chakravarty S, Orr-Gonzalez S, Lambert LE, Engels T, Thomas ML, Fasinu PS, Serre D, Gwadz RW, Walker L, DeConti DK, Mu J, Bailey JA, Sim BKL, Hoffman SL, Fay MP, Dinglasan RR, Juliano JJ, Wellems TE. Plasmodium vivax chloroquine resistance links to pvcrt transcription in a genetic cross. Nat Commun 2019; 10:4300. [PMID: 31541097 PMCID: PMC6754410 DOI: 10.1038/s41467-019-12256-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 08/26/2019] [Indexed: 12/30/2022] Open
Abstract
Mainstay treatment for Plasmodium vivax malaria has long relied on chloroquine (CQ) against blood-stage parasites plus primaquine against dormant liver-stage forms (hypnozoites), however drug resistance confronts this regimen and threatens malaria control programs. Understanding the basis of P. vivax chloroquine resistance (CQR) will inform drug discovery and malaria control. Here we investigate the genetics of P. vivax CQR by a cross of parasites differing in drug response. Gametocytogenesis, mosquito infection, and progeny production are performed with mixed parasite populations in nonhuman primates, as methods for P. vivax cloning and in vitro cultivation remain unavailable. Linkage mapping of progeny surviving >15 mg/kg CQ identifies a 76 kb region in chromosome 1 including pvcrt, an ortholog of the Plasmodium falciparum CQR transporter gene. Transcriptional analysis supports upregulated pvcrt expression as a mechanism of CQR.
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Affiliation(s)
- Juliana M Sá
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Sarah R Kaslow
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Roberto R Moraes Barros
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Nicholas F Brazeau
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Christian M Parobek
- Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Dingyin Tao
- W Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Rebecca E Salzman
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Tyler J Gibson
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | | | - Michael A Krause
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Viviana Melendez-Muniz
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Whitney A Kite
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Paul K Han
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Richard T Eastman
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Adam Kim
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Evan G Kessler
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | | | | | | | - Sachy Orr-Gonzalez
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Lynn E Lambert
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Theresa Engels
- Division of Veterinary Resources, Office of Research Services, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Marvin L Thomas
- Division of Veterinary Resources, Office of Research Services, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Pius S Fasinu
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Campbell University, Buies Creek, NC, 27506, USA
| | - David Serre
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Robert W Gwadz
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Larry Walker
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Campbell University, Buies Creek, NC, 27506, USA
| | - Derrick K DeConti
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA, 01655, USA
| | - Jianbing Mu
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Jeffrey A Bailey
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Campbell University, Buies Creek, NC, 27506, USA
- Division of Transfusion Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, 01655, USA
| | | | | | - Michael P Fay
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Rhoel R Dinglasan
- W Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
- Emerging Pathogens Institute, Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Jonathan J Juliano
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA
- Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Division of Infectious Diseases, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Thomas E Wellems
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
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14
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Fasinu PS, Nanayakkara NPD, Wang YH, Chaurasiya ND, Herath HMB, McChesney JD, Avula B, Khan I, Tekwani BL, Walker LA. Formation primaquine-5,6-orthoquinone, the putative active and toxic metabolite of primaquine via direct oxidation in human erythrocytes. Malar J 2019; 18:30. [PMID: 30700282 PMCID: PMC6352325 DOI: 10.1186/s12936-019-2658-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Accepted: 01/17/2019] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND The activity and haemolytic toxicity associated with primaquine has been linked to its reactive metabolites. The reactive metabolites are thought to be primarily formed through the action of cytochrome P450-mediated pathways. Human erythrocytes generally are not considered a significant contributor to drug biotransformation. As erythrocytes are the target of primaquine toxicity, the ability of erythrocytes to mediate the formation of reactive oxidative primaquine metabolites in the absence of hepatic enzymes, was evaluated. METHODS Primaquine and its enantiomers were incubated separately with human red blood cells and haemoglobin. Post-incubation analysis was performed with UPLC-MS/MS to identify products of biotransformation. RESULTS The major metabolite detected was identified as primaquine-5,6-orthoquinone, reflecting the pathway yielding putative active and haematotoxic metabolites of primaquine, which was formed by oxidative demethylation of 5-hydroxyprimaquine. Incubation of primaquine with haemoglobin in a cell-free system yielded similar results. It appears that the observed biotransformation is due to non-enzymatic processes, perhaps due to reactive oxygen species (ROS) present in erythrocytes or in the haemoglobin incubates. CONCLUSION This study presents new evidence that primaquine-5,6-orthoquinone, the metabolite of primaquine reflecting the oxidative biotransformation pathway, is generated in erythrocytes, probably by non-enzymatic means, and may not require transport from the liver or other tissues.
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Affiliation(s)
- Pius S Fasinu
- The National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA. .,Department of Pharmaceutical Sciences, Campbell University, Buies Creek, NC, 27501, USA.
| | - N P Dhammika Nanayakkara
- The National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA
| | - Yan-Hong Wang
- The National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA
| | - Narayan D Chaurasiya
- The National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA
| | - H M Bandara Herath
- The National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA
| | | | - Bharathi Avula
- The National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA
| | - Ikhlas Khan
- The National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA.,Department of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | - Babu L Tekwani
- The National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA.,Department of Infectious Diseases, Southern Research Institute, Birmingham, AL, USA
| | - Larry A Walker
- The National Center for Natural Products Research, The University of Mississippi, University, MS, 38677, USA. .,Department of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA.
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15
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Bello MO, Zaki AA, Aloko S, Fasinu PS, Bello EO, Ajao UL, Oguntoye OS. The genus Vitex: An overview of iridoids as chemotaxonomic marker. Beni-Suef University Journal of Basic and Applied Sciences 2018. [DOI: 10.1016/j.bjbas.2017.07.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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16
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Fasinu PS, Manda VK, Dale OR, Egiebor NO, Walker LA, Khan SI. Modulation of Cytochrome P450, P-glycoprotein and Pregnane X Receptor by Selected Antimalarial Herbs-Implication for Herb-Drug Interaction. Molecules 2017; 22:molecules22122049. [PMID: 29168799 PMCID: PMC6150001 DOI: 10.3390/molecules22122049] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 11/20/2017] [Indexed: 11/17/2022] Open
Abstract
Seven medicinal plants popularly used for treating malaria in West Africa were selected to assess herb-drug interaction potential through a series of in vitro methods. Fluorescent cytochrome P450 (CYP) assays were conducted using the recombinant CYP enzymes for CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6 and CYP3A4 to assess the effect of the methanolic extracts on the metabolic activity of CYPs. Secondly, the inhibitory effect of the extracts was evaluated on P-glycoproteins (P-gp) using calcein-AM, a fluorescent substrate, in MDCK-II and hMDR1-MDCK-II cells. The inhibition of P-gp activity was determined as a reflection of increase in calcein-AM uptake. Additionally, the enzyme induction potential of the extracts was assessed through the modulation of PXR activity in HepG2 cells transiently transfected with pSG5-PXR and PCR5 plasmid DNA. Significant inhibition of CYP activity (IC50 < 10 µg/mL) was observed with the following herbs: A. muricata [CYP2C9, 3A4 and CYP2D6]; M. indica [CYP2C9]; M. charantia [CYP2C9 and CYP2C19]; P. amarus [CYP2C19, CYP2C9 and CYP3A4]; T. diversifolia [CYP2C19 and CYP3A4]. Extracts of four herbs (P. amarus, M. charantia, T. diversifolia and A. muricata) exhibited significant inhibition of P-gp with IC50 values (µg/mL) of 17 ± 1, 16 ± 0.4, 26 ± 1, and 24 ± 1, respectively. In addition, four herbs (A. mexicana, M. charantia, P. amarus and T. diversifolia) showed a >two-fold increase in induction in PXR activity. These findings suggest that these herbs may be capable of eliciting herb-drug interactions if consumed in high quantities with concomitant use of conventional therapies.
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Affiliation(s)
- Pius S Fasinu
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Campbell University, Buies Creek, NC 27506, USA.
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA.
| | - Vamshi K Manda
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA.
| | - Olivia R Dale
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA.
| | - Nosa O Egiebor
- Department of Environmental Resources Engineering, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA.
| | - Larry A Walker
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA.
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA.
| | - Shabana I Khan
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA.
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA.
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17
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Abstract
States and the federal government are under growing pressure to legalize the use of cannabis products for medical purposes in the United States. Sixteen states have legalized (or decriminalized possession of) products high in cannabidiol (CBD) and with restricted ∆(9) -tetrahydrocannabinol (∆(9) -THC) content. In most of these states, the intent is for use in refractory epileptic seizures in children, but in a few states, the indications are broader. This review provides an overview of the pharmacology and toxicology of CBD; summarizes some of the regulatory, safety, and cultural issues relevant to the further exploitation of its antiepileptic or other pharmacologic activities; and assesses the current status and prospects for clinical development of CBD and CBD-rich preparations for medical use in the United States. Unlike Δ(9) -THC, CBD elicits its pharmacologic effects without exerting any significant intrinsic activity on the cannabinoid receptors, whose activation results in the psychotropic effects characteristic of Δ(9) -THC, and CBD possesses several pharmacologic activities that give it a high potential for therapeutic use. CBD exhibits neuroprotective, antiepileptic, anxiolytic, antipsychotic, and antiinflammatory properties. In combination with Δ(9) -THC, CBD has received regulatory approvals in several European countries and is currently under study in trials registered by the U.S. Food and Drug Administration in the United States. A number of states have passed legislation to allow for the use of CBD-rich, limited Δ(9) -THC-content preparations of cannabis for certain pathologic conditions. CBD is currently being studied in several clinical trials and is at different stages of clinical development for various medical indications. Judging from clinical findings reported so far, CBD and CBD-enriched preparations have great potential utility, but uncertainties regarding sourcing, long-term safety, abuse potential, and regulatory dilemmas remain.
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Affiliation(s)
- Pius S Fasinu
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS
| | - Sarah Phillips
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS
| | - Mahmoud A ElSohly
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS.,Department of Pharmaceutics and Drug Delivery, School of Pharmacy, The University of Mississippi, University, MS
| | - Larry A Walker
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS.,Department of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, University, MS
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18
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Adejumo OE, Kotila TR, Falusi AG, Silva BO, Nwogu JN, Fasinu PS, Babalola CP. Phenotyping and genotyping of CYP2C19 using comparative metabolism of proguanil in sickle-cell disease patients and healthy controls in Nigeria. Pharmacol Res Perspect 2016; 4:e00252. [PMID: 27713823 PMCID: PMC5045938 DOI: 10.1002/prp2.252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/04/2016] [Accepted: 07/11/2016] [Indexed: 01/22/2023] Open
Abstract
Polymorphic expression of metabolic enzymes have been identified as one of the key factors responsible for the interindividual/ethnic/racial variability in drug metabolism and effect. In Nigeria, there is a disproportionately high incidence of sickle-cell disease (SCD), a condition characterized by painful crisis frequently triggered by malaria. Proguanil, a substrate of the polymorphic CYP2C19, is a chemoprophylactic antimalarial drug widely used among SCD patients in Nigeria. This study aimed to conduct a comparative CYP2C19 phenotyping among SCD patients and healthy controls and to compare the results with those previously reported. One hundred seventy-seven unrelated subjects comprising 131 SCD patients and 46 non-SCD volunteers were phenotyped. This was carried out by collecting pooled urine samples over 8 h following PG administration. Proguanil and its major CYP2C19-dependent metabolites were measured by high-performance liquid chromatography. Metabolic ratios (MRs) were computed and employed in classifying subjects into poor or extensive metabolizers. Among SCD group, 130 (99.2%) were extensive metabolizers (EMs) and 1 (0.8%) was poor metabolizer (PM) of PG, while 95.7 and 4.3% non-SCDs were EMs and PMs, respectively. MRs ranged from 0.02 to 8.70 for SCD EMs and from 0.22 to 8.33 for non-SCD EMs . Two non-SCDs with MRs of 18.18 and 25.76 and the SCD with MR of 16.77 regarded as PMs had earlier been genotyped as CYP2C19*2/*2. Poor metabolizers of proguanil in SCD patients are reported for the first time. Regardless of clinical significance, a difference in metabolic disposition of proguanil and CYP2C19 by SCDs and non-SCDs was established.
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Affiliation(s)
- Olufunmilayo E Adejumo
- Department of Pharmaceutical and Medicinal Chemistry Faculty of Pharmacy Olabisi Onabanjo University Sagamu Nigeria; Department of Pharmaceutical Chemistry Faculty of Pharmacy University of Ibadan Ibadan Nigeria
| | - Taiwo R Kotila
- Department of Haematology College of Medicine University of Ibadan Ibadan Nigeria
| | - Adeyinka G Falusi
- Genetic and Bioethics Unit Institute of Advanced Medical Research and Training (IMRAT) College of Medicine University of Ibadan Ibadan Nigeria
| | - Boladale O Silva
- Department of Pharmaceutics and Pharmaceutical Technology Faculty of Pharmacy University of Lagos Lagos Nigeria
| | - Jacinta N Nwogu
- Department of Pharmaceutical Chemistry Faculty of Pharmacy University of Ibadan Ibadan Nigeria
| | - Pius S Fasinu
- Department of Pharmaceutical and Medicinal Chemistry Faculty of Pharmacy Olabisi Onabanjo University Sagamu Nigeria; National Center for Natural Product Research School of Pharmacy University of Mississippi Oxford Mississippi United States
| | - Chinedum P Babalola
- Department of Pharmaceutical Chemistry Faculty of Pharmacy University of Ibadan Ibadan Nigeria; Genetic and Bioethics Unit Institute of Advanced Medical Research and Training (IMRAT) College of Medicine University of Ibadan Ibadan Nigeria
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19
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Fasinu PS, Gurley BJ, Walker LA. Clinically Relevant Pharmacokinetic Herb-drug Interactions in Antiretroviral Therapy. Curr Drug Metab 2016; 17:52-64. [PMID: 26526838 DOI: 10.2174/1389200216666151103115053] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 09/30/2015] [Accepted: 10/30/2015] [Indexed: 11/22/2022]
Abstract
For healthcare professionals, the volume of literature available on herb-drug interactions often makes it difficult to separate experimental/potential interactions from those deemed clinically relevant. There is a need for concise and conclusive information to guide pharmacotherapy in HIV/AIDS. In this review, the bases for potential interaction of medicinal herbs with specific antiretroviral drugs are presented, and several botanicals are discussed for which clinically relevant interactions in humans are established. Such studies have provided, in most cases, sufficient ground to warrant the avoidance of concurrent administration of antiretroviral (ARVs) drugs with St John's wort (Hypericum perforatum), black pepper (Piper species) and grapefruit juice. Other botanicals that require caution in the use with antiretrovirals include African potato (Hypoxis hemerocallidea), ginkgo (Ginkgo biloba), ginseng (Panax species), garlic (Allium sativum), goldenseal (Hydrastis canadensis) and kava kava (Piper methysticum). The knowledge of clinically significant herb-drug interaction will be important in order to avoid herb-induced risk of sub-therapeutic exposure to ARVs (which can lead to viral resistance) or the precipitation of toxicity (which may lead to poor compliance and/or discontinuation of antiretroviral therapy).
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Affiliation(s)
- Pius S Fasinu
- National Center for Natural products Research, School of Pharmacy, University of Mississippi, University MS 38677, USA.
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20
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Fasinu PS, Tekwani BL, Avula B, Chaurasiya ND, Nanayakkara NPD, Wang YH, Khan IA, Walker LA. Pathway-specific inhibition of primaquine metabolism by chloroquine/quinine. Malar J 2016; 15:466. [PMID: 27618912 PMCID: PMC5020452 DOI: 10.1186/s12936-016-1509-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 08/27/2016] [Indexed: 12/29/2022] Open
Abstract
Background There has been some evidence to suggest that the addition of chloroquine (CQ) or quinine (QN) to 8-aminoquinoline (8-AQ) treatment regimens may increase the therapeutic efficacy of the 8-AQ and simultaneously mitigate against its haemolytic toxicity. However, both CQ and QN are considered effective, although perhaps moderate inhibitors of CYP2D6, an enzyme now regarded as necessary for primaquine (PQ) pharmacologic activity. An understanding of the influence of CQ and QN on the metabolism of PQ may shed light on the potential mechanisms of the beneficial interaction. Methods Differential metabolism of PQ enantiomers by recombinant human CYP2D6, monoamine oxidase A (MAO), and cryopreserved human hepatocytes in the presence/absence of CQ and QN. Results Both CQ and QN significantly inhibited the activity of CYP2D6. PQ depletion by MAO and human hepatocytes was not affected significantly by the presence of CQ and QN. CYP2D6-mediated hydroxylation was largely suppressed by both CQ and QN. The formation of the primary deaminated metabolites, including carboxyprimaquine (CPQ) and cyclized side chain derivative from the aldehyde (m/z 241), was not sensitive to the presence of CQ and QN. However, the appearance of the glucuronides of CPQ and PQ alcohol were significantly suppressed. CQ and QN also inhibited the appearance of the m/z 257 metabolite with a similar pattern, suggesting that it may be derived from the CPQ conjugate. The apparent quinone-imine of CPQ (m/z 289) was only partially suppressed by both QN and CQ, but with a differential pattern of inhibition for the two drugs. The m/z 274 (quinone-imine of a ring-hydroxylated PQ metabolite) and m/z 422 (an apparent glucose conjugate of PQ) metabolites in hepatocytes were strongly suppressed by both QN and CQ, perhaps a reflection of the 2D6 inhibition by these drugs. The formation of the carbamoyl glucuronide of PQ (m/z 480) was not affected by CQ/QN. Conclusion The metabolite-specific interactions in the current studies seem at variance with earlier reports of the dependence of PQ on CYP2D6 metabolism, and enhanced PQ anti-malarial activity/reduced toxicity in the presence of CQ/QN. These results suggest a complex picture in which CQ/QN may shift metabolite pathway balances towards a profile that retains efficacy, while reducing the formation or availability of toxic metabolites to erythrocytes. Alternatively, these drugs may alter transport or distribution of PQ metabolites in a fashion that reduces toxicity while maintaining efficacy against the parasite.
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Affiliation(s)
- Pius S Fasinu
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA.
| | - Babu L Tekwani
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA.,Departments of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | - Bharathi Avula
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | - Narayan D Chaurasiya
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | - N P Dhammika Nanayakkara
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | - Yan-Hong Wang
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | - Ikhlas A Khan
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA.,Departments of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | - Larry A Walker
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA.,Departments of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
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Adejumo OE, Fasinu PS, Odion JE, Silva BO, Fajemirokun TO. High Cadmium Levels in Cured Meat Products Marketed in Nigeria - Implications for Public Health. Asian Pac J Cancer Prev 2016; 17:1933-6. [PMID: 27221878 DOI: 10.7314/apjcp.2016.17.4.1933] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Heavy metals are known to disrupt important physiological processes in living cells, and have been responsible for various pathological conditions with possible contributions to cancer development. Food contamination have been identified as one of the ways humans are exposed to heavy metals. In developing countries like Nigeria, the regulatory framework for enforcing compliance with globally acceptable exposure to deleterious contaminants is poor. In the current study, thirteen samples of cured meat products of diverse origin marketed in South-west Nigeria were evaluated for lead, cadmium, chromium and nickel contents using the atomic absorption spectroscopy technique. All the samples analysed contained cadmium between 0.35 and 1.20 ppm, levels considered higher than acceptable limits in consumable products. Lead, chromium and nickel were not detected in any of the samples. As known cumulative poisons, there is the need for stringent regulatory control of these heavy metals in cured meat products imported into or produced indigenously in the country in order to minimize the risks to public health.
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Affiliation(s)
- Olufunmilayo E Adejumo
- Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmacy, Olabisi Onabanjo University, Sagamu, Nigeria E-mail :
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Fasinu PS, Avula B, Tekwani BL, Nanayakkara NPD, Wang YH, Bandara Herath HMT, McChesney JD, Reichard GA, Marcsisin SR, Elsohly MA, Khan SI, Khan IA, Walker LA. Differential kinetic profiles and metabolism of primaquine enantiomers by human hepatocytes. Malar J 2016; 15:224. [PMID: 27093859 PMCID: PMC4837544 DOI: 10.1186/s12936-016-1270-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 04/01/2016] [Indexed: 01/02/2023] Open
Abstract
Background The clinical utility of primaquine (PQ), used as a racemic mixture of two enantiomers, is limited due to metabolism-linked hemolytic toxicity in individuals with genetic deficiency in glucose-6-phosphate dehydrogenase. The current study investigated differential metabolism of PQ enantiomers in light of the suggestions that toxicity and efficacy might be largely enantioselective. Methods Stable isotope 13C-labelled primaquine and its two enantiomers (+)-PQ, (−)-PQ were separately incubated with cryopreserved human hepatocytes. Time-tracked substrate depletion and metabolite production were monitored via UHPLC–MS/MS. Results The initial half-life of 217 and 65 min; elimination rate constants (λ) of 0.19 and 0.64 h−1; intrinsic clearance (Clint) of 2.55 and 8.49 (µL/min)/million cells, which when up-scaled yielded Clint of 6.49 and 21.6 (mL/min)/kg body mass was obtained respectively for (+)- and (−)-PQ. The extrapolation of in vitro intrinsic clearance to in vivo human hepatic blood clearance, performed using the well-stirred liver model, showed that the rate of hepatic clearance of (+)-PQ was only 45 % that of (−)-PQ. Two major primary routes of metabolism were observed—oxidative deamination of the terminal amine and hydroxylations on the quinoline moiety of PQ. The major deaminated metabolite, carboxyprimaquine (CPQ) was preferentially generated from the (−)-PQ. Other deaminated metabolites including PQ terminal alcohol (m/z 261), a cyclized side chain derivative from the aldehyde (m/z 241), cyclized carboxylic acid derivative (m/z 257), a quinone-imine product of hydroxylated CPQ (m/z 289), CPQ glucuronide (m/z 451) and the glucuronide of PQ alcohol (m/z 437) were all preferentially generated from the (−)-PQ. The major quinoline oxidation product (m/z 274) was preferentially generated from (+)-PQ. In addition to the products of the two metabolic pathways, two other major metabolites were observed: a prominent glycosylated conjugate of PQ on the terminal amine (m/z 422), peaking by 30 min and preferentially generated by (+)-PQ; and the carbamoyl glucuronide of PQ (m/z 480) exclusively generated from (+)-PQ. Conclusion Metabolism of PQ showed enantioselectivity. These findings may provide important information in establishing clinical differences in PQ enantiomers.
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Affiliation(s)
- Pius S Fasinu
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | - Bharathi Avula
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | - Babu L Tekwani
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA.,Department of BioMolecular Sciences School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | - N P Dhammika Nanayakkara
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | - Yan-Hong Wang
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | - H M T Bandara Herath
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | | | - Gregory A Reichard
- Military Malaria Research Program, Experimental Therapeutics Branch, Walter Reed Army Institute of Research, 503 Robert Grant Ave, Silver Spring, MD, 20910, USA
| | - Sean R Marcsisin
- Military Malaria Research Program, Experimental Therapeutics Branch, Walter Reed Army Institute of Research, 503 Robert Grant Ave, Silver Spring, MD, 20910, USA
| | - Mahmoud A Elsohly
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA.,Departments of Pharmaceutical Sciences and Drug Delivery, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA.,ElSohly Laboratories, Inc., 5 Industrial Park Dr, Oxford, MS, 38655, USA
| | - Shabana I Khan
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA.,Department of BioMolecular Sciences School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | - Ikhlas A Khan
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA.,Department of BioMolecular Sciences School of Pharmacy, The University of Mississippi, University, MS, 38677, USA
| | - Larry A Walker
- The National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS, 38677, USA. .,Department of BioMolecular Sciences School of Pharmacy, The University of Mississippi, University, MS, 38677, USA.
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Tekwani BL, Avula B, Sahu R, Chaurasiya ND, Khan SI, Jain S, Fasinu PS, Herath HMTB, Stanford D, Nanayakkara NPD, McChesney JD, Yates TW, ElSohly MA, Khan IA, Walker LA. Enantioselective pharmacokinetics of primaquine in healthy human volunteers. Drug Metab Dispos 2015; 43:571-7. [PMID: 25637634 DOI: 10.1124/dmd.114.061127] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Primaquine (PQ), a racemic drug, is the only treatment available for radical cure of relapsing Plasmodium vivax malaria and blocking transmission of P. falciparum malaria. Recent studies have shown differential pharmacologic and toxicologic profiles of individual PQ enantiomers in rodent, dog, and primate animal models. This study was conducted in six healthy adult human volunteers to determine the plasma pharmacokinetic profile of enantiomers of PQ and carboxyprimaquine (cPQ), the major plasma metabolite. The individuals were orally administered PQ diphosphate, equivalent to 45-mg base, 30 minutes after a normal breakfast. Blood samples were collected at different time intervals, and plasma samples were analyzed for enantiomers of PQ and cPQ. Plasma PQ concentrations were low and variable for both parent enantiomers and peaked around 2-4 hours. Peak (-)-(R)-PQ concentrations ranged from 121 ng/ml to 221 ng/ml, and peak (+)-(S)-PQ concentrations ranged from 168 ng/ml to 299 ng/ml. The cPQ concentrations were much higher and were surprisingly consistent from subject to subject. Essentially all the cPQ detected in plasma was (-)-cPQ. The peak concentrations of (-)-cPQ were observed at 8 hours (range: 1104-1756 ng/ml); however, very high concentrations were sustained through 24 hours. (+)-cPQ was two orders of magnitude lower than (-)-cPQ, and in a few subjects it was detected but only under the limit of quantification. In vitro studies with primary human hepatocytes also suggested more rapid metabolism of (-)-PQ compared with (+)-PQ. The results suggest more rapid metabolism of (-)-PQ to (-) cPQ compared with (+)-PQ. Alternatively, (+)-PQ or (+)-cPQ could be rapidly converted to another metabolite(s) or distributed to tissues. This is the first clinical report on enantioselective pharmacokinetic profiles of PQ and cPQ and supports further clinical evaluation of individual PQ enantiomers.
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Affiliation(s)
- Babu L Tekwani
- National Center for Natural Products Research (B.L.T., B.A., R.S., N.D.C., S.I.K., S.J., P.S.F., H.M.T.B.H., D.S., N.P.D.N., M.A.E., I.A.K., L.A.W.), Departments of BioMolecular Sciences (B.L.T., S.I.K., S.J., I.A.K., L.A.W.) and Pharmaceutics (M.A.E.), School of Pharmacy, and Department of Student Health Services (T.W.Y.), University of Mississippi, University; Ironstone Separations, Inc., Etta (J.D.M.); ElSohly Laboratories, Inc., Oxford (M.A.E.), Mississippi
| | - Bharathi Avula
- National Center for Natural Products Research (B.L.T., B.A., R.S., N.D.C., S.I.K., S.J., P.S.F., H.M.T.B.H., D.S., N.P.D.N., M.A.E., I.A.K., L.A.W.), Departments of BioMolecular Sciences (B.L.T., S.I.K., S.J., I.A.K., L.A.W.) and Pharmaceutics (M.A.E.), School of Pharmacy, and Department of Student Health Services (T.W.Y.), University of Mississippi, University; Ironstone Separations, Inc., Etta (J.D.M.); ElSohly Laboratories, Inc., Oxford (M.A.E.), Mississippi
| | - Rajnish Sahu
- National Center for Natural Products Research (B.L.T., B.A., R.S., N.D.C., S.I.K., S.J., P.S.F., H.M.T.B.H., D.S., N.P.D.N., M.A.E., I.A.K., L.A.W.), Departments of BioMolecular Sciences (B.L.T., S.I.K., S.J., I.A.K., L.A.W.) and Pharmaceutics (M.A.E.), School of Pharmacy, and Department of Student Health Services (T.W.Y.), University of Mississippi, University; Ironstone Separations, Inc., Etta (J.D.M.); ElSohly Laboratories, Inc., Oxford (M.A.E.), Mississippi
| | - Narayan D Chaurasiya
- National Center for Natural Products Research (B.L.T., B.A., R.S., N.D.C., S.I.K., S.J., P.S.F., H.M.T.B.H., D.S., N.P.D.N., M.A.E., I.A.K., L.A.W.), Departments of BioMolecular Sciences (B.L.T., S.I.K., S.J., I.A.K., L.A.W.) and Pharmaceutics (M.A.E.), School of Pharmacy, and Department of Student Health Services (T.W.Y.), University of Mississippi, University; Ironstone Separations, Inc., Etta (J.D.M.); ElSohly Laboratories, Inc., Oxford (M.A.E.), Mississippi
| | - Shabana I Khan
- National Center for Natural Products Research (B.L.T., B.A., R.S., N.D.C., S.I.K., S.J., P.S.F., H.M.T.B.H., D.S., N.P.D.N., M.A.E., I.A.K., L.A.W.), Departments of BioMolecular Sciences (B.L.T., S.I.K., S.J., I.A.K., L.A.W.) and Pharmaceutics (M.A.E.), School of Pharmacy, and Department of Student Health Services (T.W.Y.), University of Mississippi, University; Ironstone Separations, Inc., Etta (J.D.M.); ElSohly Laboratories, Inc., Oxford (M.A.E.), Mississippi
| | - Surendra Jain
- National Center for Natural Products Research (B.L.T., B.A., R.S., N.D.C., S.I.K., S.J., P.S.F., H.M.T.B.H., D.S., N.P.D.N., M.A.E., I.A.K., L.A.W.), Departments of BioMolecular Sciences (B.L.T., S.I.K., S.J., I.A.K., L.A.W.) and Pharmaceutics (M.A.E.), School of Pharmacy, and Department of Student Health Services (T.W.Y.), University of Mississippi, University; Ironstone Separations, Inc., Etta (J.D.M.); ElSohly Laboratories, Inc., Oxford (M.A.E.), Mississippi
| | - Pius S Fasinu
- National Center for Natural Products Research (B.L.T., B.A., R.S., N.D.C., S.I.K., S.J., P.S.F., H.M.T.B.H., D.S., N.P.D.N., M.A.E., I.A.K., L.A.W.), Departments of BioMolecular Sciences (B.L.T., S.I.K., S.J., I.A.K., L.A.W.) and Pharmaceutics (M.A.E.), School of Pharmacy, and Department of Student Health Services (T.W.Y.), University of Mississippi, University; Ironstone Separations, Inc., Etta (J.D.M.); ElSohly Laboratories, Inc., Oxford (M.A.E.), Mississippi
| | - H M T Bandara Herath
- National Center for Natural Products Research (B.L.T., B.A., R.S., N.D.C., S.I.K., S.J., P.S.F., H.M.T.B.H., D.S., N.P.D.N., M.A.E., I.A.K., L.A.W.), Departments of BioMolecular Sciences (B.L.T., S.I.K., S.J., I.A.K., L.A.W.) and Pharmaceutics (M.A.E.), School of Pharmacy, and Department of Student Health Services (T.W.Y.), University of Mississippi, University; Ironstone Separations, Inc., Etta (J.D.M.); ElSohly Laboratories, Inc., Oxford (M.A.E.), Mississippi
| | - Donald Stanford
- National Center for Natural Products Research (B.L.T., B.A., R.S., N.D.C., S.I.K., S.J., P.S.F., H.M.T.B.H., D.S., N.P.D.N., M.A.E., I.A.K., L.A.W.), Departments of BioMolecular Sciences (B.L.T., S.I.K., S.J., I.A.K., L.A.W.) and Pharmaceutics (M.A.E.), School of Pharmacy, and Department of Student Health Services (T.W.Y.), University of Mississippi, University; Ironstone Separations, Inc., Etta (J.D.M.); ElSohly Laboratories, Inc., Oxford (M.A.E.), Mississippi
| | - N P Dhammika Nanayakkara
- National Center for Natural Products Research (B.L.T., B.A., R.S., N.D.C., S.I.K., S.J., P.S.F., H.M.T.B.H., D.S., N.P.D.N., M.A.E., I.A.K., L.A.W.), Departments of BioMolecular Sciences (B.L.T., S.I.K., S.J., I.A.K., L.A.W.) and Pharmaceutics (M.A.E.), School of Pharmacy, and Department of Student Health Services (T.W.Y.), University of Mississippi, University; Ironstone Separations, Inc., Etta (J.D.M.); ElSohly Laboratories, Inc., Oxford (M.A.E.), Mississippi
| | - James D McChesney
- National Center for Natural Products Research (B.L.T., B.A., R.S., N.D.C., S.I.K., S.J., P.S.F., H.M.T.B.H., D.S., N.P.D.N., M.A.E., I.A.K., L.A.W.), Departments of BioMolecular Sciences (B.L.T., S.I.K., S.J., I.A.K., L.A.W.) and Pharmaceutics (M.A.E.), School of Pharmacy, and Department of Student Health Services (T.W.Y.), University of Mississippi, University; Ironstone Separations, Inc., Etta (J.D.M.); ElSohly Laboratories, Inc., Oxford (M.A.E.), Mississippi
| | - Travis W Yates
- National Center for Natural Products Research (B.L.T., B.A., R.S., N.D.C., S.I.K., S.J., P.S.F., H.M.T.B.H., D.S., N.P.D.N., M.A.E., I.A.K., L.A.W.), Departments of BioMolecular Sciences (B.L.T., S.I.K., S.J., I.A.K., L.A.W.) and Pharmaceutics (M.A.E.), School of Pharmacy, and Department of Student Health Services (T.W.Y.), University of Mississippi, University; Ironstone Separations, Inc., Etta (J.D.M.); ElSohly Laboratories, Inc., Oxford (M.A.E.), Mississippi
| | - Mahmoud A ElSohly
- National Center for Natural Products Research (B.L.T., B.A., R.S., N.D.C., S.I.K., S.J., P.S.F., H.M.T.B.H., D.S., N.P.D.N., M.A.E., I.A.K., L.A.W.), Departments of BioMolecular Sciences (B.L.T., S.I.K., S.J., I.A.K., L.A.W.) and Pharmaceutics (M.A.E.), School of Pharmacy, and Department of Student Health Services (T.W.Y.), University of Mississippi, University; Ironstone Separations, Inc., Etta (J.D.M.); ElSohly Laboratories, Inc., Oxford (M.A.E.), Mississippi
| | - Ikhlas A Khan
- National Center for Natural Products Research (B.L.T., B.A., R.S., N.D.C., S.I.K., S.J., P.S.F., H.M.T.B.H., D.S., N.P.D.N., M.A.E., I.A.K., L.A.W.), Departments of BioMolecular Sciences (B.L.T., S.I.K., S.J., I.A.K., L.A.W.) and Pharmaceutics (M.A.E.), School of Pharmacy, and Department of Student Health Services (T.W.Y.), University of Mississippi, University; Ironstone Separations, Inc., Etta (J.D.M.); ElSohly Laboratories, Inc., Oxford (M.A.E.), Mississippi
| | - Larry A Walker
- National Center for Natural Products Research (B.L.T., B.A., R.S., N.D.C., S.I.K., S.J., P.S.F., H.M.T.B.H., D.S., N.P.D.N., M.A.E., I.A.K., L.A.W.), Departments of BioMolecular Sciences (B.L.T., S.I.K., S.J., I.A.K., L.A.W.) and Pharmaceutics (M.A.E.), School of Pharmacy, and Department of Student Health Services (T.W.Y.), University of Mississippi, University; Ironstone Separations, Inc., Etta (J.D.M.); ElSohly Laboratories, Inc., Oxford (M.A.E.), Mississippi
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Awortwe C, Fasinu PS, Rosenkranz B. Application of Caco-2 cell line in herb-drug interaction studies: current approaches and challenges. J Pharm Pharm Sci 2014; 17:1-19. [PMID: 24735758 DOI: 10.18433/j30k63] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The Caco-2 model is employed in pre-clinical investigations to predict the likely gastrointestinal permeability of drugs because it expresses cytochrome P450 enzymes, transporters, microvilli and enterocytes of identical characteristics to the human small intestine. The FDA recommends this model as integral component of the Biopharmaceutics Classification System (BCS). Most dedicated laboratories use the Caco-2 cell line to screen new chemical entities through prediction of its solubility, bioavailability and the possibility of drug-drug or herb-drug interactions in the gut lumen. However, challenges in the inherent characteristics of Caco-2 cell and inter-laboratory protocol variations have resulted to generation of irreproducible data. These limitations affect the extrapolation of data from pre-clinical research to clinical studies involving drug-drug and herb-drug interactions. This review addresses some of these caveats and enumerates the plausible current and future approaches to reduce the anomalies associated with Caco-2 cell line investigations focusing on its application in herb-drug interactions.
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Affiliation(s)
- Charles Awortwe
- Division of Clinical Pharmacology, Faculty of Medicine and Health Sciences, University of Stellenbosch, Tygerberg, Cape Town, South Africa
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Fasinu PS, Tekwani BL, Nanayakkara NPD, Avula B, Herath HMTB, Wang YH, Adelli VR, Elsohly MA, Khan SI, Khan IA, Pybus BS, Marcsisin SR, Reichard GA, McChesney JD, Walker LA. Enantioselective metabolism of primaquine by human CYP2D6. Malar J 2014; 13:507. [PMID: 25518709 PMCID: PMC4301821 DOI: 10.1186/1475-2875-13-507] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 12/11/2014] [Indexed: 11/15/2022] Open
Abstract
Background Primaquine, currently the only approved drug for the treatment and radical cure of Plasmodium vivax malaria, is still used as a racemic mixture. Clinical use of primaquine has been limited due to haemolytic toxicity in individuals with genetic deficiency in glucose-6-phosphate dehydrogenase. Earlier studies have linked its therapeutic effects to CYP2D6-generated metabolites. The aim of the current study was to investigate the differential generation of the CYP2D6 metabolites by racemic primaquine and its individual enantiomers. Methods Stable isotope 13C-labelled primaquine and its two enantiomers were incubated with recombinant cytochrome-P450 supersomes containing CYP2D6 under optimized conditions. Metabolite identification and time-point quantitative analysis were performed using LC-MS/MS. UHPLC retention time, twin peaks with a mass difference of 6, MS-MS fragmentation pattern, and relative peak area with respect to parent compound were used for phenotyping and quantitative analysis of metabolites. Results The rate of metabolism of (+)-(S)-primaquine was significantly higher (50% depletion of 20 μM in 120 min) compared to (−)-(R)-primaquine (30% depletion) when incubated with CYP2D6. The estimated Vmax (μmol/min/mg) were 0.75, 0.98 and 0.42, with Km (μM) of 24.2, 33.1 and 21.6 for (±)-primaquine, (+)-primaquine and (−)-primaquine, respectively. Three stable mono-hydroxylated metabolites, namely, 2-, 3- and 4-hydroxyprimaquine (2-OH-PQ, 3-OH-PQ, and 4-OH-PQ), were identified and quantified. 2-OH-PQ was preferentially formed from (+)-primaquine in a ratio of 4:1 compared to (−)-primaquine. The racemic (±)-primaquine showed a pattern similar to the (−)-primaquine; 2-OH-PQ accounted for about 15–17% of total CYP2D6-mediated conversion of (+)-primaquine. In contrast, 4-OH-PQ was preferentially formed with (−)-primaquine (5:1), accounting for 22% of the total (−)-primaquine conversion. 3-OH-PQ was generated from both enantiomers and racemate. 5-hydroxyprimaquine was unstable. Its orthoquinone degradation product (twice as abundant in (+)-primaquine compared to (−)-primaquine) was identified and accounted for 18–20% of the CYP2D6-mediated conversion of (+)-primaquine. Other minor metabolites included dihydroxyprimaquine species, two quinone-imine products of dihydroxylated primaquine, and a primaquine terminal alcohol with variable generation from the individual enantiomers. Conclusion The metabolism of primaquine by human CYP2D6 and the generation of its metabolites display enantio-selectivity regarding formation of hydroxylated product profiles. This may partly explain differential pharmacologic and toxicologic properties of primaquine enantiomers.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Larry A Walker
- The National Center for Natural Products Research, University of Mississippi, University, MS 38677, USA.
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Fasinu PS, Bouic PJ, Rosenkranz B. The inhibitory activity of the extracts of popular medicinal herbs on CYP1A2, 2C9, 2C19 and 3A4 and the implications for herb-drug interaction. Afr J Tradit Complement Altern Med 2014; 11:54-61. [PMID: 25392581 DOI: 10.4314/ajtcam.v11i4.9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Studies have suggested an increasing practice of concurrent herb-drug consumption. One of the major clinical risks of such concomitant herb-drug use is pharmacokinetic herb-drug interaction (HDI). This is brought about by the ability of phytochemicals to inhibit or induce the activity of metabolic enzymes. The aim of this study was to investigate the potential of the crude aqueous extracts of three popular medicinal herbs used in South Africa to inhibit major cytochrome P450 (CYP) enzymes. MATERIALS AND METHODS The extracts of Bowiea volubilis, Spirostachys africana and Tulbaghia violacea were incubated with human liver microsomes (HLM) to monitor the phenacetin O-deethylation, diclofenac 4'-hydroxylation, S-mephenytoin 4'-hydroxylation and testosterone 6β-hydroxylation as respective probe reactions for CYP1A2, CYP2C9, CYP2C19 and CYP3A4. The inhibitory activity, where observed, was profiled against the extract concentration. RESULTS Extracts of Bowiea volubilis inhibited the metabolic activity of CYP1A2 and CYP3A4 with IC50 values of 92.3 ± 5.5 µg/mL and 8.1 ± 0.6 µg/mL respectively. Similar observation with Spirostachys africana showed inhibitory activity against CYP1A2 and CYP3A4 with respective IC50 values of 14.3 ± 0.6 µg/mL and 47.4 ± 2.4 µg/mL. Tulbaghia violacea demonstrated relatively weak inhibitory activity against CYP1A2 (767.4 ± 10.8 µg/mL) and CYP2C9 (921 ± 15.3 µg/mL). CONCLUSION The results suggest the potential for HDI between the herbs and the substrates of the affected enzymes, if sufficient in vivo concentration is attained.
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Affiliation(s)
- Pius S Fasinu
- Division of Pharmacology, Faculty of Medicine and Health Sciences, University of Stellenbosch, Cape Town, South Africa ; National Centre for Natural Product Research, University of Mississippi, Oxford, United States of America
| | - Patrick J Bouic
- Synexa Life Sciences, Montague Gardens, Cape Town, South Africa ; Division of Medical Microbiology, Faculty of Medicine and Health Sciences, University of Stellenbosch, Cape Town, South Africa
| | - Bernd Rosenkranz
- Division of Pharmacology, Faculty of Medicine and Health Sciences, University of Stellenbosch, Cape Town, South Africa
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Abstract
CONTEXT Aqueous decoction of Hypoxis hemerocallidea Fisch. & C.A. Mey. (Hypoxidaceae) (Hypoxis) is widely consumed in Southern Africa by people living with HIV/AIDS, some of whom are on ARV and other medications. OBJECTIVE The aim of this study was to investigate the potential of the crude aqueous extracts of Hypoxis to inhibit major forms of CYP450 and transport proteins. MATERIALS AND METHODS Corms of Hypoxis were water-extracted and incubated (in graded concentrations: 1-100 µg/mL) with human liver microsomes (20 min) to monitor the effects on phenacetin O-deethylation, coumarin 7-hydroxylation, bupropion hydroxylation, paclitaxel 6α-hydroxylation, diclofenac 4'-hydroxylation, S-mephenytoin 4'-hydroxylation, bufuralol 1'-hydroxylation, chlorzoxazone 6-hydroxylation, midazolam 1'-hydroxylation and testosterone 6β-hydroxylation as markers for the metabolic activities of CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1 and 3A4/5, respectively. The generation of metabolites were monitored and quantified with the aid of LC-MS/MS. The potential of the extracts to inhibit human ATP-binding cassette transporter activity was assessed using recombinant MDCKII and LLC-PK1 cells over-expressing human breast cancer resistant protein and human P-glycoprotein , respectively (with Ko143 and cyclosporin A as positive controls). Similar assessment was performed with human organic anion transporting polypeptide (OATP1B1 and OATP1B3) using recombinant HEK293 cells over-expressing OATP1B1 and OATP1B3, respectively (with rifamycin and 10 µM atorvastatin as positive controls). RESULTS Extracts of Hypoxis inhibited the production of the metabolites of the substrates of the following enzymes (as compared to controls) with the indicated IC50 values (µg/mL): CYP1A2 (120.6), CYP2A6 (210.8), CYP2B6 (98.5), CYP2C8 (195.2), CYP2C9 (156) and CYP3A4/5 (185.4). The inhibition of the uptake activity of OATP1B1 and OATP1B3 were also observed with IC50 values of 93.4 and 244.8 μg/mL, respectively. DISCUSSION Extract concentrations higher than the estimated IC50 values are achievable in the gastrointestinal tract when traditional doses of Hypoxis are considered. This may have profound effects on presystemic metabolism of the drug substrates. If absorbed, systemic inhibition of metabolic enzymes/transporters by Hypoxis may be expected. CONCLUSION The result suggests that there is the potential for HDI between Hypoxis and the substrates of the affected enzymes/transporters, if sufficient in vivo concentration of Hypoxis extracts is attained.
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Affiliation(s)
- Pius S Fasinu
- Division of Pharmacology, Faculty of Medicine and Health Sciences, University of Stellenbosch , Cape Town , South Africa
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Njovane XW, Fasinu PS, Rosenkranz B. Comparative evaluation of warfarin utilisation in two primary healthcare clinics in the Cape Town area. Cardiovasc J Afr 2013; 24:19-23. [PMID: 23750346 PMCID: PMC3736381 DOI: 10.5830/cvja-2012-072] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Background Although warfarin remains the anticoagulant drug of choice in a wide range of patients, its narrow therapeutic window makes patients susceptible to a high risk of bleeding complications or failure to prevent clotting. This has necessitated therapeutic monitoring in warfarinised patients. Factors that could be responsible for the fluctuating responses to warfarin vary from pharmacogenetic to concomitant morbidity, diet and medication. In order to assess the quality of management of warfarin treatment in a local primary-care setting, the current study evaluated warfarin utilisation and monitoring records in two hospitals with different patient groups. Methods A retrospective study was undertaken in the specialised warfarin clinics at Wesfleur and Gugulethu hospitals (Western Cape, South Africa) covering all warfarin-related therapy records over a 12-month period. Data extracted from the patients’ folders included age, gender, race, weight, address, concurrent chronic illnesses, treatment and medication, indication for warfarin and INR history. Results A total of 119 patients’ folders were analysed. Attendance at the clinics reflects the demographics and racial distribution of the host location of the hospitals. While all the patients were maintained above the minimum international normalised ratio (INR) value of 2, about 50% had at least one record of INR above the cut-off value of 3.5. However, over a third of the patients (32.2%) had at least one record of INR greater than 3.5 in Gugulethu Hospital, compared to over half (58.3%) in Wesfleur Hospital. In total, atrial fibrillation was the most common indication for warfarinisation while hypertension was the most common concurrent chronic condition in warfarinised patients. All patients who received quinolone antibiotics had INR values above the cut-off point of 3.5 within the same month of the initiation of antibiotic therapy, suggesting drug-induced warfarin potentiation. Other co-medications, including beta-lactam antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs) and anti-ulcer drugs appeare to alter warfarin responses as measured by recorded INR values. Conclusion The study found inter-individual variability in the response to warfarin therapy, which cut across racial classifications. It also confirms the possible influence of concomitant morbidity on patient response to anticoagulant therapy.
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Affiliation(s)
- Xolani W Njovane
- Division of Pharmacology, Faculty of Medicine and Health Sciences, University of Stellenbosch, Cape Town, South Africa
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Fasinu PS, Gutmann H, Schiller H, James AD, Bouic PJ, Rosenkranz B. The Potential of Sutherlandia frutescens for Herb-Drug Interaction. Drug Metab Dispos 2012; 41:488-97. [DOI: 10.1124/dmd.112.049593] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Abstract
Despite the lack of sufficient information on the safety of herbal products, their use as alternative and/or complementary medicine is globally popular. There is also an increasing interest in medicinal herbs as precursor for pharmacological actives. Of serious concern is the concurrent consumption of herbal products and conventional drugs. Herb-drug interaction (HDI) is the single most important clinical consequence of this practice. Using a structured assessment procedure, the evidence of HDI presents with varying degree of clinical significance. While the potential for HDI for a number of herbal products is inferred from non-human studies, certain HDIs are well established through human studies and documented case reports. Various mechanisms of pharmacokinetic HDI have been identified and include the alteration in the gastrointestinal functions with consequent effects on drug absorption; induction and inhibition of metabolic enzymes and transport proteins; and alteration of renal excretion of drugs and their metabolites. Due to the intrinsic pharmacologic properties of phytochemicals, pharmacodynamic HDIs are also known to occur. The effects could be synergistic, additive, and/or antagonistic. Poor reporting on the part of patients and the inability to promptly identify HDI by health providers are identified as major factors limiting the extensive compilation of clinically relevant HDIs. A general overview and the significance of pharmacokinetic and pharmacodynamic HDI are provided, detailing basic mechanism, and nature of evidence available. An increased level of awareness of HDI is necessary among health professionals and drug discovery scientists. With the increasing number of plant-sourced pharmacological actives, the potential for HDI should always be assessed in the non-clinical safety assessment phase of drug development process. More clinically relevant research is also required in this area as current information on HDI is insufficient for clinical applications.
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Affiliation(s)
- Pius S. Fasinu
- Division of Pharmacology, Faculty of Health Sciences, University of StellenboschCape Town, South Africa
| | - Patrick J. Bouic
- Division of Medical Microbiology, Faculty of Health Sciences, University of StellenboschCape Town, South Africa
- Synexa Life Sciences, Montague GardensCape Town, South Africa
| | - Bernd Rosenkranz
- Division of Pharmacology, Faculty of Health Sciences, University of StellenboschCape Town, South Africa
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