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Leung JG. Ethnopsychopharmacology: Clinical and scientific writing pearls. Ment Health Clin 2023; 13:276-288. [PMID: 38058595 PMCID: PMC10696167 DOI: 10.9740/mhc.2023.12.276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 09/26/2023] [Indexed: 12/08/2023] Open
Abstract
The concept of ethnopsychopharmacology aims to predict or explain the pharmacologic response to psychiatric medications based on the influence of biologic and nonbiologic factors. Interactions involving these factors are complex and influence patient outcomes in health care. Pharmacists and other clinicians working in patient care environments, research, or medical education should engage in lifelong learning to enhance ethnopsychopharmacologic knowledge gaps, which ultimately may improve and individualize care across diverse populations. Through two cases, this paper provides pearls on how biogeographical ancestry and cytochrome P450 status may influence pharmacotherapy selection, dosing, or response. A third scenario highlights a publication, like many other published works, with deficiencies in how data on ancestry, race, and ethnicity are collected or reported. Current recommendations on the use of inclusive language in scientific writing are reviewed, with attention to specific examples.
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Marwa KJ, Kapesa A, Kamugisha E, Swedberg G. The Influence of Cytochrome P450 Polymorphisms on Pharmacokinetic Profiles and Treatment Outcomes Among Malaria Patients in Sub-Saharan Africa: A Systematic Review. Pharmgenomics Pers Med 2023; 16:449-461. [PMID: 37223718 PMCID: PMC10202199 DOI: 10.2147/pgpm.s379945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 04/24/2023] [Indexed: 05/25/2023] Open
Abstract
Background Sub-Saharan Africa (SSA) population is genetically diverse and heterogenous thus variability in drug response among individuals is predicted to be high. Cytochrome P450 (CYP450) polymorphisms is a major source of variability in drug response. This systematic review presents the influence of CYP450 single nucleotide polymorphisms (SNPs), particularly CYP3A4*1B, CYP2B6*6 and CYP3A5*3 on antimalarial drug plasma concentrations, efficacy and safety in SSA populations. Methods Searching for relevant studies was done through Google Scholar, Cochrane Central Register of controlled trials (CENTRAL), PubMed, Medline, LILACS, and EMBASE online data bases. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were used. Two independent reviewers extracted data from the studies. Results Thirteen studies reporting the influence of CYP450 SNPs on plasma concentrations, efficacy and safety were included in the final data synthesis. CYP3A4*1B, CYP3A5*5, CYP2B6*6 and CYP2C8*2 did not affect antimalarial drug plasma concentration significantly. There was no difference in treatment outcomes between malaria patients with variant alleles and those with wild type alleles. Conclusion This review reports lack of influence of CYP3A4*1B, CYP3A5*3, CYP2C8*3 and CYP2B6*6 SNPs on PK profiles, efficacy and safety in SSA among P. falciparum malaria patients.
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Affiliation(s)
- Karol J Marwa
- Department of Pharmacology, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Anthony Kapesa
- Department of Community Medicine, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Erasmus Kamugisha
- Department of Biochemistry, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Göte Swedberg
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
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Chamboko CR, Veldman W, Tata RB, Schoeberl B, Tastan Bishop Ö. Human Cytochrome P450 1, 2, 3 Families as Pharmacogenes with Emphases on Their Antimalarial and Antituberculosis Drugs and Prevalent African Alleles. Int J Mol Sci 2023; 24:ijms24043383. [PMID: 36834793 PMCID: PMC9961538 DOI: 10.3390/ijms24043383] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/30/2023] [Accepted: 02/06/2023] [Indexed: 02/10/2023] Open
Abstract
Precision medicine gives individuals tailored medical treatment, with the genotype determining the therapeutic strategy, the appropriate dosage, and the likelihood of benefit or toxicity. Cytochrome P450 (CYP) enzyme families 1, 2, and 3 play a pivotal role in eliminating most drugs. Factors that affect CYP function and expression have a major impact on treatment outcomes. Therefore, polymorphisms of these enzymes result in alleles with diverse enzymatic activity and drug metabolism phenotypes. Africa has the highest CYP genetic diversity and also the highest burden of malaria and tuberculosis, and this review presents current general information on CYP enzymes together with variation data concerning antimalarial and antituberculosis drugs, while focusing on the first three CYP families. Afrocentric alleles such as CYP2A6*17, CYP2A6*23, CYP2A6*25, CYP2A6*28, CYP2B6*6, CYP2B6*18, CYP2C8*2, CYP2C9*5, CYP2C9*8, CYP2C9*9, CYP2C19*9, CYP2C19*13, CYP2C19*15, CYP2D6*2, CYP2D6*17, CYP2D6*29, and CYP3A4*15 are implicated in diverse metabolic phenotypes of different antimalarials such as artesunate, mefloquine, quinine, primaquine, and chloroquine. Moreover, CYP3A4, CYP1A1, CYP2C8, CYP2C18, CYP2C19, CYP2J2, and CYP1B1 are implicated in the metabolism of some second-line antituberculosis drugs such as bedaquiline and linezolid. Drug-drug interactions, induction/inhibition, and enzyme polymorphisms that influence the metabolism of antituberculosis, antimalarial, and other drugs, are explored. Moreover, a mapping of Afrocentric missense mutations to CYP structures and a documentation of their known effects provided structural insights, as understanding the mechanism of action of these enzymes and how the different alleles influence enzyme function is invaluable to the advancement of precision medicine.
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Affiliation(s)
- Chiratidzo R Chamboko
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Makhanda 6139, South Africa
| | - Wayde Veldman
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Makhanda 6139, South Africa
| | - Rolland Bantar Tata
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Makhanda 6139, South Africa
| | - Birgit Schoeberl
- Translational Medicine, Novartis Institutes for BioMedical Research, 220 Massachusetts Ave, Cambridge, MA 02139, USA
| | - Özlem Tastan Bishop
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Makhanda 6139, South Africa
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Shatnawi A, Kamran Z, Al-Share Q. Pharmacogenomics of lipid-lowering agents: the impact on efficacy and safety. Per Med 2022; 20:65-86. [DOI: 10.2217/pme-2022-0041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Hyperlipidemia is a significant risk factor for cardiovascular disease morbidity and mortality. The lipid-lowering drugs are considered the cornerstone of primary and secondary prevention of atherosclerotic cardiovascular disease. Unfortunately, the lack of efficacy and associated adverse effects, ranging from mild-to-moderate to potentially life-threatening, lead to therapy discontinuation. Numerous reports support the role of gene polymorphisms in drugs' pharmacokinetic parameters and their associated adverse reactions. Therefore, this study aims to understand the pharmacogenomics of lipid-lowering drugs and the impact of genetic variants of key genes on the drugs' efficacy and toxicity. Indeed, genetically guided lipid-lowering therapy enhances overall safety, improves drug adherence and achieves long-term therapy.
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Affiliation(s)
- Aymen Shatnawi
- Department of Drug Discovery & Biomedical Sciences, College of Pharmacy, Medical University of South Carolina, 70 President St., Room 402, Charleston, SC 29425, USA
| | - Zourayz Kamran
- Department of Pharmaceutical & Administrative Sciences, University of Charleston School of Pharmacy, 2300 MacCorkle Ave SE, Charleston, WV 25304, USA
| | - Qusai Al-Share
- Department of Clinical Pharmacy, Assistant Professor of Pharmacology & Therapeutics, Faculty of Pharmacy, Jordan University of Science & Technology, P.O. Box 3030, Irbid, 22110, Jordan
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Lumefantrine plasma concentrations in uncontrolled conditions among patients treated with artemether-lumefantrine for uncomplicated plasmodium falciparum malaria in Mwanza, Tanzania. Int J Infect Dis 2022; 123:192-199. [PMID: 36064162 DOI: 10.1016/j.ijid.2022.08.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 08/19/2022] [Accepted: 08/22/2022] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Therapeutic efficacy of artemether-lumefantrine is highly dependent on adequate systemic exposure to the partner drug lumefantrine particularly day 7 lumefantrine plasma concentration. There has been contradicting findings on the role of the cut-off values in predicting treatment outcomes among malaria patients in malaria endemic regions. This study assesses the day 3 and 7 lumefantrine plasma concentrations including related determinant factors and their influence on treatment outcomes among treated Tanzanian children and adults in uncontrolled conditions (real life condition). METHODS Data was nested from an efficacy study employing the WHO protocol, 2015 for monitoring antimalarial drug efficacy. Lumefantrine plasma concentration was measured by high performance liquid chromatography with ultraviolet (HPLC-UV). RESULTS Lumefantrine plasma concentrations below 175ng/ml and 200ng/ml on day 3 and 7 did not affect adequate clinical and parasitological response (ACPR) and recurrence of infection (p = 0.428 and 0.239 respectively). Age and baseline parasitemia were not associated to day 3 median lumefantrine plasma concentrations (p = 0.08 and 0.31 respectively) and day 7 lumefantrine plasma concentrations (p = 0.07 and 0.41 respectively). However, the day 3 and day 7 lumefantrine plasma concentrations were significantly higher in males compared to females (p = 0.03 and 0.042 respectively). CONCLUSION Lumefantrine plasma concentrations below cut-off points (175ng/ml and 200ng/ml) on day 3 and 7 did not influence treatment outcomes.
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Nthontho KC, Ndlovu AK, Sharma K, Kasvosve I, Hertz DL, Paganotti GM. Pharmacogenetics of Breast Cancer Treatments: A Sub-Saharan Africa Perspective. Pharmgenomics Pers Med 2022; 15:613-652. [PMID: 35761855 PMCID: PMC9233488 DOI: 10.2147/pgpm.s308531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 05/31/2022] [Indexed: 11/30/2022] Open
Abstract
Breast cancer is the most frequent cause of cancer death in low- and middle-income countries, in particular among sub-Saharan African women, where response to available anticancer treatment therapy is often limited by the recurrent breast tumours and metastasis, ultimately resulting in decreased overall survival rate. This can also be attributed to African genomes that contain more variation than those from other parts of the world. The purpose of this review is to summarize published evidence on pharmacogenetic and pharmacokinetic aspects related to specific available treatments and the known genetic variabilities associated with metabolism and/or transport of breast cancer drugs, and treatment outcomes when possible. The emphasis is on the African genetic variation and focuses on the genes with the highest strength of evidence, with a close look on CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4/5, CYP19A1, UGT1A4, UGT2B7, UGT2B15, SLC22A16, SLC38A7, FcγR, DPYD, ABCB1, and SULT1A1, which are the genes known to play major roles in the metabolism and/or elimination of the respective anti-breast cancer drugs given to the patients. The genetic variability of their metabolism could be associated with different metabolic phenotypes that may cause reduced patients' adherence because of toxicity or sub-therapeutic doses. Finally, this knowledge enhances possible personalized treatment approaches, with the possibility of improving survival outcomes in patients with breast cancer.
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Affiliation(s)
- Keneuoe Cecilia Nthontho
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana
- Botswana-University of Pennsylvania Partnership, Gaborone, Botswana
| | - Andrew Khulekani Ndlovu
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana
| | | | - Ishmael Kasvosve
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana
| | - Daniel Louis Hertz
- Department of Clinical Pharmacy, University of Michigan College of Pharmacy, Ann Arbor, MI, USA
| | - Giacomo Maria Paganotti
- Botswana-University of Pennsylvania Partnership, Gaborone, Botswana
- Division of Infectious Diseases, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Biomedical Sciences, Faculty of Medicine, University of Botswana, Gaborone, Botswana
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Pharmacogenomics of statins: lipid response and other outcomes in Brazilian cohorts. Pharmacol Rep 2021; 74:47-66. [PMID: 34403130 DOI: 10.1007/s43440-021-00319-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/21/2021] [Accepted: 07/30/2021] [Indexed: 01/20/2023]
Abstract
Statins are inhibitors of 3-hydroxy-3-methylglutaryl-CoA reductase, a key enzyme in cholesterol biosynthesis, that are highly effective in reducing plasma low-density lipoprotein (LDL) cholesterol and decreasing the risk of cardiovascular events. In recent years, a multitude of variants in genes involved in pharmacokinetics (PK) and pharmacodynamics (PD) have been suggested to influence the cholesterol-lowering response. However, the vast majority of studies have analyzed the pharmacogenetic associations in populations in Europe and the USA, whereas data in other populations, including Brazil, are mostly lacking. This narrative review provides an update of clinical studies on statin pharmacogenomics in Brazilian cohorts exploring lipid-lowering response, adverse events and pleiotropic effects. We find that variants in drug transporter genes (SLCO1B1 and ABCB1) positively impacted atorvastatin and simvastatin response, whereas variants in genes of drug metabolizing enzymes (CYP3A5) decreased response. Furthermore, multiple associations of variants in PD genes (HMGCR, LDLR and APOB) with statin response were identified. Few studies have explored statin-related adverse events, and only ABCB1 but not SLCO1B1 variants were robustly associated with increased risk in Brazil. Statin-related pleiotropic effects were shown to be influenced by variants in PD (LDLR, NR1H2) and antioxidant enzyme (NOS3, SOD2, MTHFR, SELENOP) genes. The findings of these studies indicate that statin pharmacogenomic associations are distinctly different in Brazil compared to other populations. This review also discusses the clinical implications of pharmacogenetic studies and the rising importance of investigating rare variants to explore their association with statin response.
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Rostam-Abadi Y, Gholami J, Amin-Esmaeili M, Safarcherati A, Mojtabai R, Ghadirzadeh MR, Rahimi H, Rahimi-Movaghar A. Tramadol use and public health consequences in Iran: a systematic review and meta-analysis. Addiction 2020; 115:2213-2242. [PMID: 32196801 DOI: 10.1111/add.15059] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 11/04/2019] [Accepted: 03/18/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND AIMS Misuse of tramadol, an opioid prescription analgesic, is known as a public health challenge globally. We aimed to systematically review studies on the prevalence of non-prescribed use, regular tramadol use and dependence, tramadol-induced poisoning and mortality in Iran. METHODS Consistent with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, international (Medline, Scopus, Web of Science) and Persian (SID) databases were systematically searched up to June 2019. Other relevant data were collected through personal contacts and review of reference lists. Pooled estimates of prevalence of tramadol use in subgroups of males and females, percentage of tramadol poisoning among admitted poisoning cases, tramadol-associated seizures and mortality among tramadol poisonings and percentage of tramadol as a cause of death among fatal drug-poisoning records were estimated through a random-effects model. RESULTS A total of 84 records were included. Pooled estimates of last 12-month use of tramadol in the Iranian general population were 4.9% [95% confidence interval (CI) = 4.1-5.9] and 0.8% (95% CI = 0.2-1.8) among males and females, respectively. The estimates for last 12-month use among Iranian male and female university students were 4.8% (95% CI = 1.9-8.9) and 0.7% (95% CI = 0.3-1.1), respectively. Six heterogeneous reports indicated the existence of regular use of tramadol and dependence in Iran. Sixty-two studies provided data on tramadol-induced poisoning, seizures and mortality. The pooled estimate of the percentage of tramadol poisoning among all drug-poisoning patients was 13.1% (95% CI = 5.7-22.9). The overall estimates of seizures and mortality among tramadol-poisoning patients were 34.6% (95% CI = 29.6-39.8) and 0.7% (95% CI = 0.0-1.9), respectively. The pooled percentage of tramadol-related fatalities among drug-poisoned cases was 5.7% (95% CI = 0.5-15.4). CONCLUSION Despite control policies, tramadol use is as prevalent as the use of illicit opioids in Iran. Numerous cases of tramadol abuse, dependence, poisonings, seizures and hundreds of tramadol-related deaths have been reported in recent years.
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Affiliation(s)
- Yasna Rostam-Abadi
- Iranian National Center for Addiction Studies (INCAS), Tehran University of Medical Sciences, Tehran, Iran
| | - Jaleh Gholami
- Iranian National Center for Addiction Studies (INCAS), Tehran University of Medical Sciences, Tehran, Iran
| | - Masoumeh Amin-Esmaeili
- Iranian National Center for Addiction Studies (INCAS), Tehran University of Medical Sciences, Tehran, Iran.,Department of Mental Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Anousheh Safarcherati
- Iranian National Center for Addiction Studies (INCAS), Tehran University of Medical Sciences, Tehran, Iran
| | - Ramin Mojtabai
- Department of Mental Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | | | - Hosein Rahimi
- Division of Pharmaceuticals and Narcotics Affairs, Ministry of Health, Tehran, Iran
| | - Afarin Rahimi-Movaghar
- Iranian National Center for Addiction Studies (INCAS), Tehran University of Medical Sciences, Tehran, Iran
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Quignot N, Więcek W, Lautz L, Dorne JL, Amzal B. Inter-phenotypic differences in CYP2C9 and CYP2C19 metabolism: Bayesian meta-regression of human population variability in kinetics and application in chemical risk assessment. Toxicol Lett 2020; 337:111-120. [PMID: 33232775 DOI: 10.1016/j.toxlet.2020.11.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 11/13/2020] [Accepted: 11/19/2020] [Indexed: 01/23/2023]
Abstract
Quantifying variability in pharmacokinetics (PK) and toxicokinetics (TK) provides a science-based approach to refine uncertainty factors (UFs) for chemical risk assessment. In this context, genetic polymorphisms in cytochromes P450 (CYPs) drive inter-phenotypic differences and may result in reduction or increase in metabolism of drugs or other xenobiotics. Here, an extensive literature search was performed to identify PK data for probe substrates of the human polymorphic isoforms CYP2C9 and CYP2C19. Relevant data from 158 publications were extracted for markers of chronic exposure (clearance and area under the plasma concentration-time curve) and analysed using a Bayesian meta-regression model. Enzyme function (EF), driven by inter-phenotypic differences across a range of allozymes present in extensive and poor metabolisers (EMs and PMs), and fraction metabolised (Fm), were identified as exhibiting the highest impact on the metabolism. The Bayesian meta-regression model provided good predictions for such inter-phenotypic differences. Integration of population distributions for inter-phenotypic differences and estimates for EF and Fm allowed the derivation of CYP2C9- and CYP2C19-related UFs which ranged from 2.7 to 12.7, and were above the default factor for human variability in TK (3.16) for PMs and major substrates (Fm >60%). These results provide population distributions and pathway-related UFs as conservative in silico options to integrate variability in CYP2C9 and CYP2C19 metabolism using in vitro kinetic evidence and in the absence of human data. The future development of quantitative extrapolation models is discussed with particular attention to integrating human in vitro and in vivo PK or TK data with pathway-related variability for chemical risk assessment.
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Affiliation(s)
| | | | - Leonie Lautz
- Risk Assessment Department, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Maisons-Alfort, France
| | - Jean-Lou Dorne
- European Food Safety Authority, Via Carlo Magno 1A, 43126, Parma, Italy
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Ndadza A, Thomford NE, Mukanganyama S, Wonkam A, Ntsekhe M, Dandara C. The Genetics of Warfarin Dose-Response Variability in Africans: An Expert Perspective on Past, Present, and Future. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2020; 23:152-166. [PMID: 30883300 DOI: 10.1089/omi.2019.0018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Coumarins such as warfarin are prescribed for prevention and treatment of thromboembolic disorders. Warfarin remains the most widely prescribed and an anticoagulant of choice in Africa. Warfarin use is, however, limited by interindividual variability in pharmacokinetics and a narrow therapeutic index. The difference in patients' pharmacodynamic responses to warfarin has been attributed to genetic variation in warfarin metabolism and molecular targets (e.g., CYP2C9 and VKORC1) and host-environment interactions. This expert review offers a synthesis of human genetics studies in Africans with respect to pharmacogenetics-informed warfarin dosing. We identify areas that need future research attention or could benefit from harnessing existing pharmacogenetics knowledge toward rational and optimal therapeutics with warfarin in African patients. A literature search was conducted until January 2019. A total of 343 articles were retrieved from nine African countries: Botswana, Ethiopia, Egypt, Ghana, Kenya, South Africa, Sudan, Tanzania, and Mozambique. We found 19 studies on genetics of warfarin treatment specifically among Africans. Genes examined included CYP2C9, VKORC1, CYP4F2, APOE, CALU, GGCX, and EPHX1. CYP2C9*2 and *3 alleles were highly frequent among Egyptians, while rare in other African populations. CYP2C9*5, *8, *9, and *11, and VKORC1 Asp36Tyr genetic variants explained warfarin variability in Africans better, compared to CYP2C9*2 and *3. In Africa, there is limited pharmacogenetics data on warfarin. Therefore, future research and funding commitments should be prioritized to ensure safe and effective use of warfarin in Africa. Lessons learned in Africa from the science of pharmacogenetics would inform rational therapeutics in hematology, cardiology, and surgical specialties worldwide.
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Affiliation(s)
- Arinao Ndadza
- 1 Pharmacogenomics and Drug Metabolism Research Group, Division of Human Genetics, Department of Pathology, Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Nicholas Ekow Thomford
- 1 Pharmacogenomics and Drug Metabolism Research Group, Division of Human Genetics, Department of Pathology, Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | | | - Ambroise Wonkam
- 1 Pharmacogenomics and Drug Metabolism Research Group, Division of Human Genetics, Department of Pathology, Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Mpiko Ntsekhe
- 3 Division of Cardiology, Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Collet Dandara
- 1 Pharmacogenomics and Drug Metabolism Research Group, Division of Human Genetics, Department of Pathology, Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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Tshabalala S, Choudhury A, Beeton-Kempen N, Martinson N, Ramsay M, Mancama D. Targeted ultra-deep sequencing of a South African Bantu-speaking cohort to comprehensively map and characterize common and novel variants in 65 pharmacologically-related genes. Pharmacogenet Genomics 2019; 29:167-178. [PMID: 31162291 PMCID: PMC6675649 DOI: 10.1097/fpc.0000000000000380] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 04/16/2019] [Indexed: 01/11/2023]
Abstract
BACKGROUND African populations are characterised by high genetic diversity, which provides opportunities for discovering and elucidating novel variants of clinical importance, especially those affecting therapeutic outcome. Significantly more knowledge is however needed before such populations can take full advantage of the advances in precision medicine. Coupled with the need to concisely map and better understand the pharmacological implications of genetic diversity in populations of sub-Sharan African ancestry, the aim of this study was to identify and characterize known and novel variants present within 65 important absorption, distribution, metabolism and excretion genes. PATIENTS AND METHODS Targeted ultra-deep next-generation sequencing was used to screen a cohort of 40 South African individuals of Bantu ancestry. RESULTS We identified a total of 1662 variants of which 129 are novel. Moreover, out of the 1662 variants 22 represent potential loss-of-function variants. A high level of allele frequency differentiation was observed for variants identified in this study when compared with other populations. Notably, on the basis of prior studies, many appear to be pharmacologically important in the pharmacokinetics of a broad range of drugs, including antiretrovirals, chemotherapeutic drugs, antiepileptics, antidepressants, and anticoagulants. An in-depth analysis was undertaken to interrogate the pharmacogenetic implications of this genetic diversity. CONCLUSION Despite the new insights gained from this study, the work illustrates that a more comprehensive understanding of population-specific differences is needed to facilitate the development of pharmacogenetic-based interventions for optimal drug therapy in patients of African ancestry.
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Affiliation(s)
- Sibongile Tshabalala
- Division of Human Genetics, National Health Laboratory Service, School of Pathology, Faculty of Health Sciences
- Sydney Brenner Institute for Molecular Bioscience (SBIMB), Faculty of Health Sciences
- CSIR Biosciences Unit, Pretoria, South Africa
| | - Ananyo Choudhury
- Sydney Brenner Institute for Molecular Bioscience (SBIMB), Faculty of Health Sciences
| | | | - Neil Martinson
- Perinatal HIV Research Unit, Baragwanath Hospital and Faculty of Health Sciences
- Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg
| | - Michèle Ramsay
- Division of Human Genetics, National Health Laboratory Service, School of Pathology, Faculty of Health Sciences
- Sydney Brenner Institute for Molecular Bioscience (SBIMB), Faculty of Health Sciences
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Elmaasarani Z, Mardis C, Gylten L, Taber DJ, Fleming J, Patel N, Baliga P, Rao V, Rohan V, DuBay D, Pilch NA. Protocol-based nurse coordinator management of ambulatory tacrolimus dosing in de novo renal transplant recipients-A single-center experience with a large African American population. Clin Transplant 2019; 33:e13701. [PMID: 31461791 DOI: 10.1111/ctr.13701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 07/12/2019] [Accepted: 08/22/2019] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Transplant nurse (RN) coordinators review tacrolimus levels frequently and would be capable of making dose adjustments autonomously if not limited by their license. Collaborative practice agreements could be an answer; thus, the aim of this evaluation was to determine if an RN-driven protocol could be used safely and effectively to manage tacrolimus in ambulatory kidney transplant (KTX) recipients. METHODS This was a retrospective review of all solitary adult KTX recipients between August 1, 2016, and July 29, 2017. The primary objective was to evaluate protocol adherence and frequency of use, and secondary objectives were to evaluate the utility of the protocol both overall and based on ethnicity. RESULTS A total of 173 patients were included in the evaluation (59% African American [AA], 41% non-African American [non-AA). RN coordinators followed the protocol for 75% of tacrolimus adjustments; however, they only responded to 27% of the overall levels. There was no difference in 180-day tacrolimus-associated readmission (15% AA vs 5% non-AA, P = .06), biopsy-proven acute rejection (4% AA vs 7% non-AA, P = .363), or hyperkalemia (34% AA vs 32% non-AA, P = .87) between groups. CONCLUSIONS Transplant nurse coordinators are capable of accurately following a protocol for tacrolimus dosage adjustment in a large, racially diverse kidney transplant center.
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Affiliation(s)
- Zana Elmaasarani
- Department of Clinical Pharmacy and Outcomes Sciences, College of Pharmacy, Medical University of South Carolina, Charleston, SC, USA
| | | | - Logan Gylten
- Department of Clinical Pharmacy and Outcomes Sciences, College of Pharmacy, Medical University of South Carolina, Charleston, SC, USA
| | - David J Taber
- Department of Surgery, Medical University of South Carolina, Charleston, SC, USA.,Department of Pharmacy, Ralph H Johnson VAMC, Charleston, SC, USA
| | - James Fleming
- Department of Surgery, Medical University of South Carolina, Charleston, SC, USA
| | - Neha Patel
- Department of Clinical Pharmacy and Outcomes Sciences, College of Pharmacy, Medical University of South Carolina, Charleston, SC, USA
| | - Prabhakar Baliga
- Department of Surgery, Medical University of South Carolina, Charleston, SC, USA
| | - Vinaya Rao
- Department of Surgery, Medical University of South Carolina, Charleston, SC, USA
| | - Vinayak Rohan
- Department of Surgery, Medical University of South Carolina, Charleston, SC, USA
| | - Derek DuBay
- Department of Surgery, Medical University of South Carolina, Charleston, SC, USA
| | - Nicole A Pilch
- Department of Clinical Pharmacy and Outcomes Sciences, College of Pharmacy, Medical University of South Carolina, Charleston, SC, USA
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13
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Kleinmahon JA, Gralla J, Kirk R, Auerbach SR, Henderson HT, Wallis GA, Ramakrishnan K, Singh RK, Caldwell RL, Savage AJ, Everitt MD. Cardiac allograft vasculopathy and graft failure in pediatric heart transplant recipients after rejection with severe hemodynamic compromise. J Heart Lung Transplant 2019; 38:277-284. [DOI: 10.1016/j.healun.2018.12.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 11/14/2018] [Accepted: 12/18/2018] [Indexed: 11/25/2022] Open
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14
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Novillo A, Gaibar M, Romero-Lorca A, Chaabani H, Amir N, Moral P, Esteban ME, Fernández-Santander A. UDP-glucuronosyltransferase genetic variation in North African populations: a comparison with African and European data. Ann Hum Biol 2019; 45:516-523. [PMID: 30616396 DOI: 10.1080/03014460.2018.1559354] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND Genetic variation in glucuronosyltransferases (UGT) is crucial in drug metabolism and risk of some diseases. AIM To examine genetic variation in UGT in North African populations. SUBJECTS AND METHODS Allele frequencies of SNPs UGT1A424Thr, UGT1A448Val, UGT2B1585Tyr, UGT2B15523Thr and UGT2B17 CNV deletion from Morocco, Algeria, Tunisia and Libya were compared to European and Sub-Saharan populations. RESULTS North Africans are the group with the highest genetic heterogeneity given by internal differences in the occurrence of UGT2B17 deletion, UGT1A448Val and UGT1A4 haplotypes. UGT2B15 SNPs differentiate Sub-Saharans from the rest of the populations. CONCLUSION North African populations show a high frequency of carriers of UGT2B15523Thr, a variant linked to an increased risk of prostate cancer. High Atlas Moroccans and Algerians show low frequency of UGT2B17del, a variant associated with high concentrations of testosterone and oestradiol.
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Affiliation(s)
- Apolonia Novillo
- a Basic Biomedical Sciences Department , Universidad Europea de Madrid , Madrid , Spain
| | - María Gaibar
- a Basic Biomedical Sciences Department , Universidad Europea de Madrid , Madrid , Spain
| | - Alicia Romero-Lorca
- a Basic Biomedical Sciences Department , Universidad Europea de Madrid , Madrid , Spain
| | - Hassen Chaabani
- b Faculty of Pharmacy , University of Monastir , Monastir , Tunisia
| | - Nadir Amir
- c Laboratoire de Biochimie Appliquée, 5 Faculté des Sciences de la Nature et de la Vie , Université de Bejaia , Bejaia , Algeria
| | - Pedro Moral
- d Section of Zoology and Biological Anthropology, Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology , Universitat de Barcelona , Barcelona , Spain.,e Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona , Barcelona , Spain
| | - M Esther Esteban
- d Section of Zoology and Biological Anthropology, Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology , Universitat de Barcelona , Barcelona , Spain.,e Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona , Barcelona , Spain
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15
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Gaibar M, Novillo A, Romero-Lorca A, Esteban ME, Fernández-Santander A. Pharmacogenetics of ugt genes in North African populations. THE PHARMACOGENOMICS JOURNAL 2018; 18:609-612. [PMID: 30061569 PMCID: PMC6150910 DOI: 10.1038/s41397-018-0034-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 03/09/2018] [Accepted: 05/14/2018] [Indexed: 11/18/2022]
Affiliation(s)
- M Gaibar
- Biomedical and Health Sciences Faculty, Universidad Europea de Madrid, Tajo s/n, 28670, Villaviciosa de Odón, Madrid, Spain
| | - A Novillo
- Biomedical and Health Sciences Faculty, Universidad Europea de Madrid, Tajo s/n, 28670, Villaviciosa de Odón, Madrid, Spain
| | - A Romero-Lorca
- Biomedical and Health Sciences Faculty, Universidad Europea de Madrid, Tajo s/n, 28670, Villaviciosa de Odón, Madrid, Spain
| | - M E Esteban
- Faculty of Biology, University of Barcelona, Diagonal 645, 08028, Barcelona, Spain.,Institut de Reçerca de la Biodiversitat (IRBio), University of Barcelona, Barcelona, Spain
| | - A Fernández-Santander
- Biomedical and Health Sciences Faculty, Universidad Europea de Madrid, Tajo s/n, 28670, Villaviciosa de Odón, Madrid, Spain.
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16
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Shah RR, Gaedigk A. Precision medicine: does ethnicity information complement genotype-based prescribing decisions? Ther Adv Drug Saf 2018; 9:45-62. [PMID: 29318005 PMCID: PMC5753996 DOI: 10.1177/2042098617743393] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 10/30/2017] [Indexed: 12/16/2022] Open
Abstract
Inter-ethnic differences in drug response are all too well known. These are underpinned by a number of factors, including pharmacogenetic differences across various ethnic populations. Precision medicine relies on genotype-based prescribing decisions with the aim of maximizing efficacy and mitigating the risks. When there is no access to genotyping tests, ethnicity is frequently regarded as a proxy of the patient's probable genotype on the basis of overall population-based frequency of genetic variations in the ethnic group the patient belongs to, with some variations being ethnicity-specific. However, ever-increasing transcontinental migration of populations and the resulting admixing of populations have undermined the utility of self-identified ethnicity in predicting the genetic ancestry, and therefore the genotype, of the patient. An example of the relevance of genetic ancestry of a patient is the inadequate performance of European-derived pharmacogenetic dosing algorithms of warfarin in African Americans, Brazilians and Caribbean Hispanics. Consequently, genotyping a patient potentially requires testing for all known clinically actionable variants that the patient may harbour, and new variants that are likely to be identified using state-of the art next-generation sequencing-based methods. Furthermore, self-identified ethnicity is associated with a number of ethnicity-related attributes and non-genetic factors that potentially influence the risk of phenoconversion (genotype-phenotype discordance), which may adversely impact the success of genotype-based prescribing decisions. Therefore, while genotype-based prescribing decisions are important in implementing precision medicine, ethnicity should not be disregarded.
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Affiliation(s)
- Rashmi R. Shah
- Pharmaceutical Consultant, 8 Birchdale, Gerrards Cross, Buckinghamshire, SL9 7JA, UK
| | - Andrea Gaedigk
- Director, Pharmacogenetics Core Laboratory, Clinical Pharmacology, Toxicology & Therapeutic Innovation, Children’s Mercy-Kansas City, Kansas City, MO and School of Medicine, University of Missouri-Kansas City, MO, USA
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Tacrolimus Trough Concentration Variability and Disparities in African American Kidney Transplantation. Transplantation 2017; 101:2931-2938. [PMID: 28658199 DOI: 10.1097/tp.0000000000001840] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Low tacrolimus concentrations have been associated with higher risk of acute rejection, particularly within African American (AA) kidney transplant recipients; little is known about intrapatient tacrolimus variabilities impact on racial disparities. METHODS Ten year, single-center, longitudinal cohort study of kidney recipients. Intrapatient tacrolimus variability was assessed using the coefficient of variation (CV) measured between 1 month posttransplant and the clinical event, with a comparable period assessed in those without events. Pediatrics, nontacrolimus/mycophenolate regimens, and nonrenal transplants were excluded. Multivariable Cox regression models were used to analyze data. RESULTS One thousand four hundred eleven recipients were included (54.4% AA) with 39 521 concentrations used to assess intrapatient tacrolimus CV. Overall, intrapatient tacrolimus CV was higher in AAs versus non-AAs (39.9 ± 19.8 % vs 34.8 ± 15.8% P < 0.001). Tacrolimus variability was a significant risk factor for deleterious clinical outcomes. A 10% increase in tacrolimus CV augmented the risk of acute rejection by 20% (adjusted hazard ratio, 1.20, 1.13-1.28; P < 0.001) and the risk of graft loss by 30% (adjusted hazard ratio, 1.30, 1.23-1.37; P < 0.001), with significant effect modification by race for acute rejection, but not graft loss. High tacrolimus variability (CV >40%) was a significant explanatory variable for disparities in AAs; the crude relative risk of acute rejection in AAs was reduced by 46% when including tacrolimus variability in modeling and reduced by 40% for graft loss. CONCLUSIONS These data demonstrate that intrapatient tacrolimus variability is strongly associated with acute rejection in AAs and graft loss in all patients. Tacrolimus variability is a significant explanatory variable for disparities in AA recipients.
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18
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Disease burden and the role of pharmacogenomics in African populations. GLOBAL HEALTH EPIDEMIOLOGY AND GENOMICS 2017; 2:e1. [PMID: 29868213 PMCID: PMC5870420 DOI: 10.1017/gheg.2016.21] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 11/22/2016] [Accepted: 11/24/2016] [Indexed: 12/15/2022]
Abstract
Background The burden of communicable and non-communicable diseases in Sub-Saharan Africa poses a challenge in achieving quality healthcare. Although therapeutic drugs have generally improved health, their efficacy differs from individual to individual. Variability in treatment response is mainly because of genetic variants that affect the pharmacokinetics and pharmacodynamics of drugs. Method The intersection of disease burden and therapeutic intervention is reviewed, and the status of pharmacogenomics knowledge in African populations is explored. Results The most commonly studied variants with pharmacogenomics relevance are discussed, especially in genes coding for enzymes that affect the response to drugs used for HIV, malaria, sickle cell disease and cardiovascular diseases. Conclusions The genetically diverse African population is likely to benefit from a pharmacogenomics-based healthcare approach, especially with respect to reduction of drug side effects, and separation of responders and non-responders leading to optimized drug choices and doses for each patient.
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Jaja C, Barrett N, Patel N, Lyon M, Xu H, Kutlar A. Progressing Preemptive Genotyping of CYP2C19 Allelic Variants for Sickle Cell Disease Patients. Genet Test Mol Biomarkers 2016; 20:609-615. [PMID: 27551817 DOI: 10.1089/gtmb.2016.0001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
AIMS Interindividual variability in drug response and adverse effects have been described for proton pump inhibitors, anticonvulsants, selective serotonin reuptake inhibitors, tricyclic antidepressants, and anti-infectives, but little is known about the safety and efficacy of these medications in patients with sickle cell disease (SCD). We genotyped the CYP2C19 gene which has been implicated in the metabolism of these drugs in an SCD patient cohort to determine the frequencies of reduced function, increased function, or complete loss-of-function variants. MATERIALS AND METHODS DNAs from 165 unrelated SCD patients were genotyped for nine CYP2C19 (*2, *3, *4, *5, *6, *7,*8, *12, and *17) alleles using the iPLEX® ADME PGx multiplex panel. RESULTS Three CYP2C19 alleles (*2, *12, and *17) were detected with the following frequencies: 0.209, 0.006, and 0.236, respectively. The predicted phenotype frequencies were distributed as extensive (31.5%), intermediate (24.8%), poor (5.5%), ultrarapid (30.3%), and unknown metabolizers (7.9%). DISCUSSION Prognostic genotyping is potentially useful for identifying SCD patients with allelic variants linked to proven clinical pharmacokinetic consequences for several drugs metabolized by the CYP2C19 gene. However, the main challenge to implementing a genetics-guided prescribing practice is ensuring concordance between CYP2C19 genotypes and metabolic phenotypes in SCD patients.
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Affiliation(s)
- Cheedy Jaja
- 1 College of Nursing, University of Cincinnati , Cincinnati, Ohio
| | - Nadine Barrett
- 2 Department of Medicine, Georgia Regents University , Augusta, Georgia
| | - Niren Patel
- 2 Department of Medicine, Georgia Regents University , Augusta, Georgia
| | - Matt Lyon
- 3 Department of Emergency Medicine, Georgia Regents University , Augusta, Georgia
| | - Hongyan Xu
- 4 Department of Biostatistics, Georgia Regents University , Augusta, Georgia
| | - Abdullah Kutlar
- 2 Department of Medicine, Georgia Regents University , Augusta, Georgia
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20
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Alessandrini M, Chaudhry M, Dodgen TM, Pepper MS. Pharmacogenomics and Global Precision Medicine in the Context of Adverse Drug Reactions: Top 10 Opportunities and Challenges for the Next Decade. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2016; 20:593-603. [PMID: 27643672 PMCID: PMC5072285 DOI: 10.1089/omi.2016.0122] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In a move indicative of the enthusiastic support of precision medicine, the U.S. President Barack Obama announced the Precision Medicine Initiative in January 2015. The global precision medicine ecosystem is, thus, receiving generous support from the United States ($215 million), and numerous other governments have followed suit. In the context of precision medicine, drug treatment and prediction of its outcomes have been important for nearly six decades in the field of pharmacogenomics. The field offers an elegant solution for minimizing the effects and occurrence of adverse drug reactions (ADRs). The Clinical Pharmacogenetics Implementation Consortium (CPIC) plays an important role in this context, and it aims at specifically guiding the translation of clinically relevant and evidence-based pharmacogenomics research. In this forward-looking analysis, we make particular reference to several of the CPIC guidelines and their role in guiding the treatment of highly relevant diseases, namely cardiovascular disease, major depressive disorder, cancer, and human immunodeficiency virus, with a view to predicting and managing ADRs. In addition, we provide a list of the top 10 crosscutting opportunities and challenges facing the fields of precision medicine and pharmacogenomics, which have broad applicability independent of the drug class involved. Many of these opportunities and challenges pertain to infrastructure, study design, policy, and science culture in the early 21st century. Ultimately, rational pharmacogenomics study design and the acquisition of comprehensive phenotypic data that proportionately match the genomics data should be an imperative as we move forward toward global precision medicine.
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Affiliation(s)
- Marco Alessandrini
- Department of Immunology, Faculty of Health Sciences, and Institute for Cellular and Molecular Medicine, South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, University of Pretoria , Pretoria, South Africa
| | - Mamoonah Chaudhry
- Department of Immunology, Faculty of Health Sciences, and Institute for Cellular and Molecular Medicine, South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, University of Pretoria , Pretoria, South Africa
| | - Tyren M Dodgen
- Department of Immunology, Faculty of Health Sciences, and Institute for Cellular and Molecular Medicine, South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, University of Pretoria , Pretoria, South Africa
| | - Michael S Pepper
- Department of Immunology, Faculty of Health Sciences, and Institute for Cellular and Molecular Medicine, South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, University of Pretoria , Pretoria, South Africa
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21
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Arici M, Özhan G. CYP2C9, CYPC19 and CYP2D6 gene profiles and gene susceptibility to drug response and toxicity in Turkish population. Saudi Pharm J 2016; 25:376-380. [PMID: 28344492 PMCID: PMC5357098 DOI: 10.1016/j.jsps.2016.09.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 09/09/2016] [Indexed: 01/15/2023] Open
Abstract
Pharmacogenetics is a vast field covering drug discovery research, the genetic basis of pharmacokinetics and dynamics, genetic testing and clinical management in diseases. Pharmacogenetic approach usually focuses on variations of drug transporters, drug targets, drug metabolizing enzymes and other biomarker genes. Cytochrome P450 (CYP) enzymes, an essential source of variability in drug-response, play role in not only phase I-dependent metabolism of xenobiotics but also metabolism of endogenous compounds such as steroids, vitamins and fatty acids. CYP2C9, CYP2C19 and CYP2D6 enzymes being highly polymorphic are responsible for metabolism of a variety of drug groups. In the study, it was determined the genotype and allele frequency of CYP2C9∗2, CYP2C19∗3, CYP2C19∗2, CYP2C19∗3, CYP2C19∗17, CYP2D6∗9 and CYP2D6∗41, very common and functional single-nucleotide polymorphisms (SNPs), in healthy volunteers. The genotype distributions were consistent with the Hardy-Weinberg equilibrium in the population (p > 0.05). It is believed that the determination of polymorphisms in the enzymes may be beneficial in order to prevention or reduction in adverse effects and death. The recessive allele frequencies of CYP2C9∗2, CYP2C19∗3, CYP2C19∗2, CYP2C19∗3, CYP2C19∗17, CYP2D6∗9 and CYP2D6∗41 were 11, 13, 12, 13, 25, 4 and 15%, respectively. According to the obtained results, the carriers of CYP2D6∗9 variant allele should be received higher doses of the drugs metabolizing with this enzyme in Turkish population, while the carriers of other variant alleles do not generally have any requirement of dose regimen.
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Affiliation(s)
| | - Gül Özhan
- Corresponding author. Fax: +90 2124400252.
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22
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Mouton JP, Cohen K, Maartens G. Key toxicity issues with the WHO-recommended first-line antiretroviral therapy regimen. Expert Rev Clin Pharmacol 2016; 9:1493-1503. [PMID: 27498720 DOI: 10.1080/17512433.2016.1221760] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
INTRODUCTION WHO recommends tenofovir, efavirenz, and lamivudine or emtricitabine for first-line antiretroviral therapy (ART) in adults, which replaced more toxic regimens using stavudine, zidovudine or nevirapine. Areas covered: We searched Pubmed to identify observational studies and randomized controlled trials reporting toxicity of these antiretrovirals published between 2011 and 2016, and hand-searched abstracts presented at major HIV conferences in 2015 and 2016, focusing on data from sub-Saharan Africa. Tenofovir's nephrotoxicity manifests as mild renal tubular dysfunction (common and of uncertain clinical significance), acute kidney injury (rare), and chronic declining glomerular filtration rate (common). African studies, which include high proportions of patients with renal dysfunction from opportunistic diseases, report population improvement in renal function after starting tenofovir-based ART. Tenofovir modestly decreases bone mineral density, and there is emerging data that this increases fracture risk. Efavirenz commonly causes early self-limiting neuropsychiatric toxicity and hypersensitivity rashes. Recent studies have highlighted its long-term neuropsychiatric effects, notably suicidality and neurocognitive impairment, and metabolic toxicities (dyslipidemia, dysglycemia, and lipoatrophy). We point out the challenges clinicians face in the recognition and attribution of adverse drug reactions. Expert commentary: Tenofovir and efavirenz are generally well tolerated, but both are associated with potentially serious toxicities. Pharmacovigilance systems in resource-limited settings with high HIV burden should be strengthened.
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Affiliation(s)
- Johannes P Mouton
- a Division of Clinical Pharmacology, Department of Medicine , University of Cape Town , Cape Town , South Africa
| | - Karen Cohen
- a Division of Clinical Pharmacology, Department of Medicine , University of Cape Town , Cape Town , South Africa
| | - Gary Maartens
- a Division of Clinical Pharmacology, Department of Medicine , University of Cape Town , Cape Town , South Africa
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23
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Arici M, Özhan G. The genetic profiles of CYP1A1, CYP1A2 and CYP2E1 enzymes as susceptibility factor in xenobiotic toxicity in Turkish population. Saudi Pharm J 2016; 25:294-297. [PMID: 28344482 PMCID: PMC5355561 DOI: 10.1016/j.jsps.2016.06.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 06/12/2016] [Indexed: 01/19/2023] Open
Abstract
Evaluation and sequencing of heritable alterations in the human genome and the large-scale identification of gene polymorphism for understanding the genetic background of individuals in response to potential toxicants are provided by toxicogenetics. Cytochrome P450 (CYP) enzymes play role not only phase I-dependent metabolism of xenobiotics but also metabolism of endogenous compounds. CYP1A1, CYP1A2 and CYP2E1 enzymes, which are in phase I enzymes, are responsible for metabolic activation and detoxification of several chemical compounds. In the present study, it was determined the genotype and allele frequency of CYP1A1∗2A, CYP1A2∗1C, CYP1A2∗1F, CYP2E1 and CYP2E1∗6, very common and functional single-nucleotide polymorphisms (SNPs), in Turkish healthy volunteers. It is believed that the determination of polymorphisms in the enzymes may be beneficial to prevent and reduce and adverse effects and death in response to drugs. The allele frequencies of these genes were 24%, 9%, 33%, 42%, and 12%, respectively. In the present study, the genotype profile of Turkish population was determined about critical enzymes for xenobiotic metabolism. It is suggested that the obtained results might be beneficial in order to dose adjustment of drugs and prevention of adverse reactions, and further investigation about mentioned enzymes and their polymorphisms.
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Affiliation(s)
- Merve Arici
- Istanbul University, Faculty of Pharmacy, Department of Pharmaceutical Toxicology, Beyazıt 34116, Istanbul, Turkey
| | - Gül Özhan
- Istanbul University, Faculty of Pharmacy, Department of Pharmaceutical Toxicology, Beyazıt 34116, Istanbul, Turkey
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24
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Motshoge T, Tawe L, Muthoga CW, Allotey J, Romano R, Quaye I, Paganotti GM. Cytochrome P450 2C8*2 allele in Botswana: Human genetic diversity and public health implications. Acta Trop 2016; 157:54-8. [PMID: 26836270 DOI: 10.1016/j.actatropica.2016.01.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 01/18/2016] [Accepted: 01/27/2016] [Indexed: 11/26/2022]
Abstract
Human cytochrome P450 2C8 is a highly polymorphic gene and shows variation according to ethnicity. The CYP2C8*2 is a slow drug metabolism allele and shows 10-24% frequency in Black populations. The objective of this study was to assess the prevalence of CYP2C8*2 allele in Botswana among the San (or Bushmen) and the Bantu ethnic groups. For that purpose we recruited 544 children of the two ethnicities in three districts of Botswana from primary schools, collected blood samples, extracted DNA and genotyped them through PCR-based restriction fragment length polymorphism analysis. The results demonstrated that in the San the prevalence of the CYP2C8*2 allele is significantly higher than among the Bantu-related ethnic groups (17.5% and 8.5% for San and Bantu, respectively; P=0.00002). These findings support the evidence of a different genetic background of the San with respect to Bantu-related populations, and highlight a possible higher risk of longer drug clearance or poor level of activation of pro-drugs among the San group.
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25
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Shah RR, Gaedigk A, LLerena A, Eichelbaum M, Stingl J, Smith RL. CYP450 genotype and pharmacogenetic association studies: a critical appraisal. Pharmacogenomics 2016; 17:259-75. [DOI: 10.2217/pgs.15.172] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Despite strong pharmacological support, association studies using genotype-predicted phenotype as a variable have yielded conflicting or inconclusive evidence to promote personalized pharmacotherapy. Unless the patient is a genotypic poor metabolizer, imputation of patient's metabolic capacity (or metabolic phenotype), a major factor in drug exposure-related clinical response, is a complex and highly challenging task because of limited number of alleles interrogated, population-specific differences in allele frequencies, allele-specific substrate-selectivity and importantly, phenoconversion mediated by co-medications and inflammatory co-morbidities that modulate the functional activity of drug metabolizing enzymes. Furthermore, metabolic phenotype and clinical outcomes are not binary functions; there is large intragenotypic and intraindividual variability. Therefore, the ability of association studies to identify relationships between genotype and clinical outcomes can be greatly enhanced by determining phenotype measures of study participants and/or by therapeutic drug monitoring to correlate drug concentrations with genotype and actual metabolic phenotype. To facilitate improved analysis and reporting of association studies, we propose acronyms with the prefixes ‘g’ (genotype-predicted phenotype) and ‘m’ (measured metabolic phenotype) to better describe this important variable of the study subjects. Inclusion of actually measured metabolic phenotype, and when appropriate therapeutic drug monitoring, promises to reveal relationships that may not be detected by using genotype alone as the variable.
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Affiliation(s)
| | - Andrea Gaedigk
- Clinical Pharmacology, Toxicology &, Therapeutic Innovation, Children's Mercy-Kansas City, 2401 Gillham Rd, Kansas City, MO 64108, USA
- School of Medicine, University of Missouri-Kansas City, MO, USA
| | - Adrián LLerena
- CICAB Clinical Research Centre, Extremadura University Hospital & Medical School, Badajoz, Spain
| | - Michel Eichelbaum
- Dr. Margarete Fischer-Bosch – Institut für Klinische Pharmakologie, 70376 Stuttgart Auerbachstr., 112 Germany
| | - Julia Stingl
- Centre for Translational Medicine, University of Bonn Medical School, Bonn, Germany
| | - Robert L Smith
- Department of Surgery & Cancer, Faculty of Medicine, Imperial College, South Kensington Campus, London, UK
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Xia Z, Wei H, Duan J, Zhou T, Yang Z, Xu F. Chronic unpredicted mild stress-induced depression alter saxagliptin pharmacokinetics and CYP450 activity in GK rats. PeerJ 2016; 4:e1611. [PMID: 26819853 PMCID: PMC4727972 DOI: 10.7717/peerj.1611] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 12/29/2015] [Indexed: 12/19/2022] Open
Abstract
Background. This study was to explore the pharmacokinetics of saxagliptin (Sax) in Goto–Kakizaki (GK) rats complicated with depression induced by chronic unpredicted mild stress (CUMS). The comorbidity of diabetic patients with depression is becoming more and more epidemic. Whether depression mental disorder alters the pharmacokinetics of hypoglycemic drugs in diabetes patients is not clear. Methods. Five-week-old male GK rats were kept in the cage for 7 weeks in a specific pathogen free (SPF)-grade lab until the emergence of diabetes and were then divided into two groups: control group and depression model group. Rats in the CUMS-induced depression group were exposed to a series of stressors for 8 weeks. Plasma serotonin and dopamine levels and behavior of open-field test were used to confirm the establishment of the depression model. All rats were given 0.5 mg/kg Sax orally after 8 weeks and blood samples were collected at different time points. The Sax concentration was assayed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The CYP450 activity of the liver microsomes was determined by using cocktails of probe drugs in which the activities of CYP enzymes were assessed through the determination of the production of the probe drugs. Results. Statistically significant differences in Sax pharmacokinetics were observed for area under curve, clearance, peak concentration, peak time and mean residence time between the depression rats and the control rats, while no statistical differences were observed for half-time and distribution volume by HPLC-MS/MS analysis. The CYP450 activity had different changes in the depression group. Conclusions. These results indicated that CUMS-induced depression alters the drug metabolic process of Sax and CYP450 activity of the liver microsomal enzymes in GK rats.
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Affiliation(s)
- Zhengchao Xia
- Department of Pharmacy, Fengxian Central Hospital Graduate Training Base, Liaoning Medical University , Shanghai , China
| | - Hongyan Wei
- Department of Pharmacy, Southern Medical University Affiliated Fengxian Central Hospital , Shanghai , China
| | - Jingjing Duan
- Department of Pharmacy, Southern Medical University Affiliated Fengxian Central Hospital , Shanghai , China
| | - Ting Zhou
- Department of Pharmacy, Southern Medical University Affiliated Fengxian Central Hospital , Shanghai , China
| | - Zhen Yang
- Department of Pharmacy, Fengxian Central Hospital Graduate Training Base, Liaoning Medical University , Shanghai , China
| | - Feng Xu
- Department of Pharmacy, Fengxian Central Hospital Graduate Training Base, Liaoning Medical University, Shanghai, China; Department of Pharmacy, Southern Medical University Affiliated Fengxian Central Hospital, Shanghai, China
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Pharmacogenetic comparison of CYP2D6 predictive and measured phenotypes in a South African cohort. THE PHARMACOGENOMICS JOURNAL 2015; 16:566-572. [PMID: 26503815 DOI: 10.1038/tpj.2015.76] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 08/20/2015] [Accepted: 09/08/2015] [Indexed: 11/08/2022]
Abstract
The relationship between genetic variation in CYP2D6 and variable drug response represents a potentially powerful pharmacogenetic tool. However, little is known regarding this relationship in the genetically diverse South African population. The aim was therefore to evaluate the relationship between predicted and measured CYP2D6 phenotype. An XL-PCR+Sequencing approach was used to determine CYP2D6 genotype in 100 healthy volunteers and phenotype was predicted using activity scores. With dextromethorphan as the probe drug, metabolic ratios served as a surrogate measure of in vivo CYP2D6 activity. Three-hour plasma metabolic ratios of dextrorphan/dextromethorphan were measured simultaneously using semi-automated online solid phase extraction coupled with tandem mass spectrometry. Partial adaptation of the activity score system demonstrated a strong association between genotype and phenotype, as illustrated by a kappa value of 0.792, inter-rater discrepancy of 0.051 and sensitivity of 72.7%. Predicted phenotype frequencies using the modified activity score were 1.3% for poor metabolisers (PM), 7.6% for intermediate metabolisers (IM) and 87.3% for extensive metabolisers (EM). Measured phenotype frequencies were 1.3% for PM, 13.9% for IM and 84.8% for EM. Comprehensive CYP2D6 genotyping reliably predicts CYP2D6 activity in this South African cohort and can be utilised as a valuable pharmacogenetic tool.
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Human Leukocyte Antigen Diversity: A Southern African Perspective. J Immunol Res 2015; 2015:746151. [PMID: 26347896 PMCID: PMC4549606 DOI: 10.1155/2015/746151] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 07/26/2015] [Indexed: 12/30/2022] Open
Abstract
Despite the increasingly well-documented evidence of high genetic, ethnic, and linguistic diversity amongst African populations, there is limited data on human leukocyte antigen (HLA) diversity in these populations. HLA is part of the host defense mechanism mediated through antigen presentation to effector cells of the immune system. With the high disease burden in southern Africa, HLA diversity data is increasingly important in the design of population-specific vaccines and the improvement of transplantation therapeutic interventions. This review highlights the paucity of HLA diversity data amongst southern African populations and defines a need for information of this kind. This information will support disease association studies, provide guidance in vaccine design, and improve transplantation outcomes.
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Dodgen TM, Drögemöller BI, Wright GEB, Warnich L, Steffens FE, Cromarty AD, Alessandrini M, Pepper MS. Evaluation of predictive CYP2C19 genotyping assays relative to measured phenotype in a South African cohort. Pharmacogenomics 2015; 16:1343-54. [PMID: 26244421 DOI: 10.2217/pgs.15.80] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
AIM To align predicted and measured CYP2C19 phenotype in a South African cohort. MATERIALS & METHODS Genotyping of CYP2C19*2, *3, *9, *15, *17, *27 and *28 was performed using PCR-RFLP, and an activity score (AS) system was used to predict phenotype. True phenotype was measured using plasma concentrations of omeprazole and its metabolite 5'-hydroxyomperazole. RESULTS Partial genotype-phenotype discrepancies were reported, and an adapted AS system was developed, which showed a marked improvement in phenotype prediction. Results highlight the need for a more comprehensive CYP2C19 genotyping approach to improve prediction of omeprazole metabolism. CONCLUSION Evidence for the utility of a CYP2C19 AS system is provided, for which the accuracy can be further improved by means of comprehensive genotyping and substrate-specific modification.
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Affiliation(s)
- Tyren M Dodgen
- Department of Pharmacology, University of Pretoria, Pretoria, South Africa.,Department of Immunology, Faculty of Health Sciences, University of Pretoria, PO Box 2034, Pretoria 0001, South Africa.,Institute for Cellular & Molecular Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Britt I Drögemöller
- Department of Genetics, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Galen E B Wright
- Department of Genetics, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Louise Warnich
- Department of Genetics, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Francois E Steffens
- Department of Statistics, Faculty of Natural & Agricultural Sciences, University of Pretoria, Pretoria, South Africa
| | - A Duncan Cromarty
- Department of Pharmacology, University of Pretoria, Pretoria, South Africa
| | - Marco Alessandrini
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, PO Box 2034, Pretoria 0001, South Africa.,Institute for Cellular & Molecular Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Michael S Pepper
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, PO Box 2034, Pretoria 0001, South Africa.,Institute for Cellular & Molecular Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Department of Genetic Medicine & Development, Faculty of Medicine, University of Geneva, Switzerland
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Shah RR. Inter-ethnic differences in drug response: Implications for drug development and complying with drug regulation. ACTA ACUST UNITED AC 2015. [DOI: 10.3109/10601333.2015.1064131] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Dodgen TM, Eloff A, Mataboge C, Roos LJL, van Staden WCW, Pepper MS. Risperidone-associated adverse drug reactions and CYP2D6 polymorphisms in a South African cohort. Appl Transl Genom 2015; 5:40-6. [PMID: 26937359 PMCID: PMC4745369 DOI: 10.1016/j.atg.2015.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 05/02/2015] [Indexed: 11/26/2022]
Abstract
Background Contradictory information exists regarding the influence of CYP2D6 polymorphisms on adverse drug reactions (ADRs) (extrapyramidal symptoms (EPS) and weight gain) related to risperidone treatment. This prompted us to evaluate the influence of CYP2D6 genetic variation in a cohort of South African patients who presented with marked movement disorders and/or weight gain while on risperidone treatment. Methods Patients who were experiencing marked risperidone ADRs were recruited from Weskoppies Public Psychiatric Hospital. As poor or intermediate metabolism was expected, comprehensive CYP2D6 sequence variations were evaluated using XL-PCR + Sequencing. Results No statistically significant association was found between CYP2D6 poor metabolism and risperidone ADRs. An inverse relationship between EPS and weight gain was however identified. A novel CYP2D6 allele was identified which is unlikely to affect metabolism based on in silico evaluation. Conclusion CYP2D6 variation appeared not to be a good pharmacogenetic marker for predicting risperidone-related ADRs in this naturalistic South African cohort. Evaluation of a larger cohort would be needed to confirm these observations, including an examination of the role of potential intermediaries between the hypothesised genetic and clinical phenotypes.
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Affiliation(s)
- Tyren M Dodgen
- Department of Pharmacology, School of Medicine, University of Pretoria, South Africa; Institute for Cellular and Molecular Medicine, Faculty of Health Sciences, University of Pretoria, South Africa
| | - Arinda Eloff
- Department of Immunology, School of Medicine, University of Pretoria, South Africa
| | - Connie Mataboge
- Department of Psychiatry, School of Medicine, University of Pretoria, South Africa
| | - Louw J L Roos
- Department of Psychiatry, School of Medicine, University of Pretoria, South Africa
| | | | - Michael S Pepper
- Department of Immunology, School of Medicine, University of Pretoria, South Africa; Institute for Cellular and Molecular Medicine, Faculty of Health Sciences, University of Pretoria, South Africa; Department of Genetic Medicine and Development, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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Čolić A, Alessandrini M, Pepper MS. Pharmacogenetics of CYP2B6, CYP2A6 and UGT2B7 in HIV treatment in African populations: focus on efavirenz and nevirapine. Drug Metab Rev 2014; 47:111-23. [PMID: 25391641 DOI: 10.3109/03602532.2014.982864] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The CYP450 and UGT enzymes are involved in phase I and phase II metabolism of the majority of clinically prescribed drugs, including the non-nucleoside reverse transcriptase inhibitors, efavirenz and nevirapine, used in the treatment of HIV/AIDS. Variations in the activity of these enzymes due to gene polymorphisms can affect an individual's drug response or may lead to adverse drug reactions. There is an inter-ethnic distribution in the frequency of these polymorphisms, with African populations exhibiting higher genetic diversity compared to other populations. African specific alleles with clinical relevance have also emerged. Given the high prevalence of HIV/AIDS in sub-Saharan Africa, understanding the frequency of pharmacogenetically relevant alleles in populations of African origin, and their impact on efavirenz and nevirapine metabolism, is becoming increasingly critical. This review aims to investigate ethnic variation of CYP2B6, CYP2A6 and UGT2B7, and to understand the pharmacogenetic relevance when comparing frequencies in African populations to other populations worldwide.
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Affiliation(s)
- Antoinette Čolić
- Department of Biochemistry, Faculty of Natural and Agricultural SciencesSchool of Biological Science, University of Pretoria , Pretoria , South Africa and
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Marwa KJ, Schmidt T, Sjögren M, Minzi OMS, Kamugisha E, Swedberg G. Cytochrome P450 single nucleotide polymorphisms in an indigenous Tanzanian population: a concern about the metabolism of artemisinin-based combinations. Malar J 2014; 13:420. [PMID: 25363545 PMCID: PMC4228099 DOI: 10.1186/1475-2875-13-420] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Accepted: 10/25/2014] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Artemisinin-based combinations currently recommended for treatment of uncomplicated Plasmodium falciparum malaria in many countries of sub-Saharan Africa are substrates of CYP enzymes. The cytochrome enzyme system is responsible for metabolism of about 80-90% of clinically used drugs. It is, therefore, important to obtain the pharmacogenetics of the population in the region with respect to these combinations and thereby enable practitioners to predict treatment outcomes. The aim of this study was to detect and determine allelic frequencies of CYP2C8*2, CYP2C8*3, CYP3A4*1B, CYP3A5*3 and CYP2B6*6 variant alleles in a Tanzanian indigenous population. METHODS Genomic DNA extraction from blood obtained from 256 participants who escorted patients at Karume Health Centre in Mwanza Tanzania, was carried out using the Gene JET™ Genomic DNA purification kit (Thermo Scientific). Genotyping for the cytochrome P450 variant alleles was performed using predesigned primers. Amplification was done by PCR while differentiation between alleles was done by restriction fragment length polymorphism (PCR-RFLP) (for CYP2C8*2, CYP2C8*3) and sequencing (for CYP2B6*6, CYP3A5*3 and CYP3A4*1B). RESULTS CYP2C8*2, CYP2C8*3, CYP3A5*3, CYP3A4*1B and CYP2B6*6 variant allelic frequencies were found to be 19,10,16,78 and 36% respectively. CONCLUSION Prevalence of CYP2C8*2, CYP3A5*3, CYP3A4*1B and CYP2B6*6 mutations in a Tanzanian population/subjects are common. The impact of these point mutations on the metabolism of anti-malarial drugs, particularly artemisinin-based combinations, and their potential drug-drug interactions (DDIs) needs to be further evaluated.
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Affiliation(s)
- Karol J Marwa
- Department of Pharmacology, Catholic University of Health and Allied Sciences, Mwanza, Tanzania.
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Alessandrini M, Pepper MS. Priority pharmacogenetics for the African continent: focus on CYP450. Pharmacogenomics 2014; 15:385-400. [PMID: 24533717 DOI: 10.2217/pgs.13.252] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Countries in Africa have a high burden of communicable disease, and are experiencing an increase in noncommunicable diseases due to the effects of globalization, industrialization and urbanization. The costs incurred through adverse drug reactions and nonresponsiveness to therapy further aggravates the situation, and the application of pharmacogenetic principles is likely to provide some relief. Having undertaken an extensive evaluation of CYP450 reports in Africa, our objective was to map out areas of need based on regional disease burdens. The data confirms a paucity of CYP450 reports and illustrates large regions for which no population information exists. There is a dire need to address the health problems of Africa, and wide-scale pharmacogenetic profiling of these populations will add significantly to improving patient care on the continent. Priority pharmacogenetics for the African continent gives precedence to the profiling of clinically relevant pharmacogenetic biomarkers, and defines the immediate need in the context of disease burden.
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Affiliation(s)
- Marco Alessandrini
- Department of Immunology & The Institute for Cellular & Molecular Medicine, Faculty of Health Sciences, University of Pretoria, South Africa
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Absence of the human CYP2C8*3 allele in Ugandan children exposed to Plasmodium falciparum malaria. INFECTION GENETICS AND EVOLUTION 2014; 27:432-5. [DOI: 10.1016/j.meegid.2014.08.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 08/05/2014] [Accepted: 08/16/2014] [Indexed: 11/20/2022]
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Spina E, de Leon J. Clinical applications of CYP genotyping in psychiatry. J Neural Transm (Vienna) 2014; 122:5-28. [DOI: 10.1007/s00702-014-1300-5] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 08/18/2014] [Indexed: 12/13/2022]
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Dandara C, Swart M, Mpeta B, Wonkam A, Masimirembwa C. Cytochrome P450 pharmacogenetics in African populations: implications for public health. Expert Opin Drug Metab Toxicol 2014; 10:769-85. [PMID: 24588448 DOI: 10.1517/17425255.2014.894020] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Africa harbors a disproportionate burden of disease when taking into account the triple challenge caused by HIV/AIDS, tuberculosis (TB) and malaria, against a backdrop of an increasing burden of noncommunicable diseases. More than 80% of therapeutic drugs used in the management of these diseases/conditions are metabolized by CYP enzymes that exhibit genetic polymorphisms. AREAS COVERED There is variability in the expression and activities of CYPs resulting in interindividual differences in the response to standard doses of therapeutic drugs, due to genetic polymorphisms, which exhibit both quantitative and qualitative differences between racial and between ethnic groups. The review aims to evaluate the implications of the genetic variation in CYPs on the public health of Africans. The CYPs reviewed here metabolize most of the commonly used therapeutic drugs and include CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 3A4 and 3A5. Allele frequencies are compared between African ethnic groups and among populations of African, Asian and European origin. Data are obtained from our own studies and literature. EXPERT OPINION The variability in the pattern of genetic variation between populations translates into differences in drug response. Understanding CYP variability improves rational drug use and has public health significance.
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Affiliation(s)
- Collet Dandara
- University of Cape Town, Faculty of Health Sciences, Pharmacogenetics and Cancer Research Group, Division of Human Genetics, Department of Clinical Laboratory Sciences , Anzio Road Observatory, 7925, Cape Town , South Africa +27 21 406 6506 ;
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Naidoo P, Chetty VV, Chetty M. Impact of CYP polymorphisms, ethnicity and sex differences in metabolism on dosing strategies: the case of efavirenz. Eur J Clin Pharmacol 2014; 70:379-89. [PMID: 24390631 DOI: 10.1007/s00228-013-1634-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 12/18/2013] [Indexed: 01/11/2023]
Abstract
PURPOSE Differences in drug metabolism due to cytochrome P450 (CYP) polymorphisms may be significant enough to warrant different dosing strategies in carriers of specific cytochrome P450 (CYP) polymorphisms, especially for drugs with a narrow therapeutic index. The impact of such polymorphisms on drug plasma concentrations and the resulting dosing strategies are presented in this review, using the example of efavirenz (EFV). METHODS A structured literature search was performed to extract information pertaining to EFV metabolism and the influence of polymorphisms of CYP2B6, ethnicity, sex and drug interactions on plasma concentrations of EFV. The corresponding dosing strategies developed for carriers of specific CYP2B6 genotypes were also reviewed. RESULTS The polymorphic CYP2B6 enzyme, which is the major enzyme in the EFV metabolic pathway, is a key determinant for the significant inter-individual differences seen in EFV pharmacokinetics and pharmacodynamics (PKPD). Ethnic differences and the associated prevalence of CYP2B6 polymorphisms result in significant differences in the PKPD associated with a standard 600 mg per day dose of EFV, warranting dosage reduction in carriers of specific CYP2B6 polymorphisms. Drug interactions and auto-induction also influence EFV PKPD significantly. CONCLUSION Using EFV as an example of a drug with a narrow therapeutic index and a high inter-patient variability in plasma concentrations corresponding to a standard dose of the drug, this review demonstrates how genotyping of the primary metabolising enzyme can be useful for appropriate dosage adjustments in individuals. However, other variables such as drug interactions and auto-induction may necessitate plasma concentration measurements as well, prior to personalising the dose.
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Affiliation(s)
- Panjasaram Naidoo
- University of KwaZulu Natal, School of Health Science, Discipline of Pharmaceutical Sciences, Private Bag X54001, Durban, 4001, KZN, South Africa,
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