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Frequency of CYP2B6 Alleles in Major Iranian Ethnicities, Affecting Response to Efavirenz. Genet Res (Camb) 2022; 2022:5754776. [PMID: 36320932 PMCID: PMC9605844 DOI: 10.1155/2022/5754776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/29/2022] [Accepted: 10/03/2022] [Indexed: 11/17/2022] Open
Abstract
Introduction Efavirenz is an antihuman immunodeficiency virus (HIV) drug metabolized by cytochrome P450 2B6 (CYP2B6) enzyme. Cytochrome P450 2B6 is an enzyme that in humans is encoded by the CYP2B6 gene. Polymorphisms of this gene play a crucial role in the metabolism of drugs such as Efavirenz. This study aims to evaluate the frequency of three clinically significant CYP2B6 polymorphisms (CYP2B6∗6 (516G > T), CYP2B6∗4 (785A > G), and CYP2B6∗5 (1459C > T)) in three major Iranian ethnicities. Methods One hundred forty-seven participants from three main Iranian ethnicities were included in this study. After DNA extraction, CYP2B6∗6 (516G > T), CYP2B6∗4 (785A > G), and CYP2B6∗5 (1459C > T) were genotyped using tetra-primer amplification refractory mutation system polymerase chain reaction (ARMS-PCR). Results The frequency of the mutated allele in the Iranian population for CYP2B6∗6 (516G > T) was 41.50 (95% CI: 35.81, 47.36), which was significantly lower than in Kurds (59.62, 95% CI: 45.10, 72.99). Similarly, Kurds had a higher frequency of mutated allele of CYP2B6∗5 (1459C > T) (46.15%, 95% CI: 32.23, 60.53) than in Iranians (24.49%, 95% CI: 19.68, 29.82). The frequency of A and G alleles of CYP2B6∗4 (785A > G) was 62.59% (95% CI: 56.78, 68.13) and 37.41 (95% CI: 31.87, 43.22), respectively. Conclusion Kurds are at higher risk of adverse drug reactions (ADRs) and insufficient anti-HIV response compared to other Iranians.
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Velozo CDA, Lamarão FRM, Alvarado-Arnez LE, Cardoso CC. Pharmacogenetics of HIV therapy: State of the art in Latin American countries. Genet Mol Biol 2022; 45:e20220120. [PMID: 36190287 PMCID: PMC9527759 DOI: 10.1590/1678-4685-gmb-2022-0120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 07/07/2022] [Indexed: 12/01/2022] Open
Abstract
The use of combined antiretroviral therapy (cART) has resulted in a remarkable reduction in morbidity and mortality of people living with HIV worldwide. Nevertheless, interindividual variations in drug response often impose a challenge to cART effectiveness. Although personalized therapeutic regimens may help overcome incidence of adverse reactions and therapeutic failure attributed to host factors, pharmacogenetic studies are often restricted to a few populations. Latin American countries accounted for 2.1 million people living with HIV and 1.4 million undergoing cART in 2020-21. The present review describes the state of art of HIV pharmacogenetics in this region and highlights that such analyses remain to be given the required relevance. A broad analysis of pharmacogenetic markers in Latin America could not only provide a better understanding of genetic structure of these populations, but might also be crucial to develop more informative dosing algorithms, applicable to non-European populations.
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O'Connell KS, Swart M, McGregor NW, Dandara C, Warnich L. Pharmacogenetics of Antiretroviral Drug Response and Pharmacokinetic Variations in Indigenous South African Populations. OMICS : A JOURNAL OF INTEGRATIVE BIOLOGY 2018; 22:589-597. [PMID: 30235109 DOI: 10.1089/omi.2018.0117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Interindividual and interethnic differences in response to antiretroviral drugs (ARVs) are influenced by genetic variation. The few genomic studies conducted among African-Americans and African ethnic groups do not reflect the extensive genetic diversity within African populations. ARVs are widely used in Africa. Therefore, genomic characterization of African populations is required before genotype-guided dosing becomes possible. The aim of this study was to determine and report on the frequency of genetic variants in genes implicated in metabolism and transport of ARVs in South African populations. The study comprised 48 self-reported South African Colored (SAC) and 296 self-reported Black African (BA) individuals. Allele and genotype frequency distributions for 93 variants contributing to metabolism and transport of ARVs were compared between groups, and other global populations. Fifty-three variants had significant differences in allele and genotype frequencies when comparing SAC and BA groups. Thirteen of these have strong clinical annotations, affecting efavirenz and tenofovir pharmacokinetics. This study provides a summary of the genetic variation within genes implicated in metabolism and transport of ARVs in indigenous South African populations. The observed differences between indigenous population groups, and between these groups and global populations, demonstrate that data generated from specific African populations cannot be used to infer genetic diversity within other populations on the continent. These results highlight the need for comprehensive characterization of genetic variation within indigenous African populations, and the clinical utility of these variants in ARV dosing for global precision medicine. Population pharmacogenetics is a nascent field of global health and warrants further research and education.
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Affiliation(s)
- Kevin S O'Connell
- 1 Systems Genetics Working Group, Department of Genetics, Stellenbosch University , Stellenbosch, South Africa
| | - Marelize Swart
- 2 Pharmacogenomics and Drug Metabolism Group, Division of Human Genetics, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town , Cape Town, South Africa
| | - Nathaniel W McGregor
- 1 Systems Genetics Working Group, Department of Genetics, Stellenbosch University , Stellenbosch, South Africa
| | - Collet Dandara
- 2 Pharmacogenomics and Drug Metabolism Group, Division of Human Genetics, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town , Cape Town, South Africa
| | - Louise Warnich
- 1 Systems Genetics Working Group, Department of Genetics, Stellenbosch University , Stellenbosch, South Africa
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Polymorphisms in cytochrome P450 are associated with extensive efavirenz pharmacokinetics and CNS toxicities in an HIV cohort in Botswana. THE PHARMACOGENOMICS JOURNAL 2018; 18:678-688. [PMID: 29855606 PMCID: PMC6151142 DOI: 10.1038/s41397-018-0028-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 04/03/2018] [Accepted: 04/13/2018] [Indexed: 01/11/2023]
Abstract
Inter-individual variability in efavirenz (EFV) pharmacokinetics and dynamics are dominantly driven by the polymorphism in cytochrome P450 (CYP) isoenzyme 2B6 516G>T. We hypothesized that additional CYP polymorphisms mediate the relationship between CYP2B6 516G>T, EFV metabolism, and clinical events. We investigated 21 SNPs in 814 HIV-infected adults initiating EFV-based therapy in Botswana for population pharmacokinetics, CNS toxicities, and treatment outcomes. Two SNPs (rs28399499 and rs28399433) showed reduced apparent oral EFV clearance. Four SNPs (rs2279345, rs4803417, rs4802101, and rs61663607) showed extensive clearance. Composite CYP2B-mediated EFV metabolism was significantly associated with CNS toxicity (p=0.04), with extensive metabolizers reporting more and slow and very slow metabolizers reporting less toxicity after one month compared to intermediate metabolizers. Composite CYP2B6 metabolism was not associated with composite early treatment failure. In conclusion, our data suggest that CNS-related toxicities might not be solely the result of super-therapeutic parent EFV concentrations in HIV-infected individuals in patients of African ancestry.
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Reay R, Dandara C, Viljoen M, Rheeders M. CYP2B6 Haplotype Predicts Efavirenz Plasma Concentration in Black South African HIV-1-Infected Children: A Longitudinal Pediatric Pharmacogenomic Study. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2018; 21:465-473. [PMID: 28816644 DOI: 10.1089/omi.2017.0078] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
South Africa has the highest burden of the human immunodeficiency virus (HIV) infection globally. Efavirenz (EFV), a frequently used drug against HIV infection, displays a relationship between drug concentration and pharmacodynamics effects clinically. However, haplotype-based genetic variation in drug metabolism in a pediatric sample has been little considered in a longitudinal long-term context. CYP2B6 plays a key role in variation of EFV plasma concentration through altered drug metabolism. We report here on a prospective clinical pharmacogenomics/pharmacokinetic study of Bantu-speaking children, importantly, over a period of 24 months post-initiation of EFV-based treatment in South Africa. We characterized the HIV-1-infected children (n = 60) for the CYP2B6 c.516G>T, c.785A>G, c.983T>C, and c.1459C>T single nucleotide polymorphisms (SNPs). These SNPs were determined using polymerase chain reaction/restricted fragment length polymorphism and SNaPshot genotyping. Longitudinal mid-dose EFV plasma concentrations were determined by LC-MS/MS and association analyses with genotypes and haplotypes at 1, 3, and 24 months were performed. The CYP2B6 c.516T/T genotype showed significantly higher EFV plasma concentrations (p < 0.001) compared to non 516T-allele carriers at all three time points. The minor allele frequencies (MAF) for CYP2B6 c.516T, c.785G, c.983C, and c.1459T were 0.410, 0.408, 0.110, and 0.000 respectively. Haplotypes were constructed using CYP2B6 c.516G>T,-c.785A>G and c.983T>C. The haplotype T-G-T presented with significantly increased EFV plasma concentrations compared to the reference G-A-T haplotype at 1, 3, and 24 months (p = 0.009; p = 0.003; p = 0.001), suggesting that the T-G-T haplotype predisposes a risk of EFV plasma concentrations >4 μg/mL. The clinical implications of these pharmacogenomics observations for EFV toxicity and treatment resistance warrant further future research.
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Affiliation(s)
- Riaan Reay
- 1 Division of Pharmacology, Centre of Excellence for Pharmaceutical Sciences (Pharmacen), North-West University , Potchefstroom, South Africa
| | - Collet Dandara
- 2 Division of Human Genetics, Department of Pathology, Faculty of Health Sciences, University of Cape Town , Cape Town, South Africa
| | - Michelle Viljoen
- 1 Division of Pharmacology, Centre of Excellence for Pharmaceutical Sciences (Pharmacen), North-West University , Potchefstroom, South Africa
| | - Malie Rheeders
- 1 Division of Pharmacology, Centre of Excellence for Pharmaceutical Sciences (Pharmacen), North-West University , Potchefstroom, South Africa
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Abstract
OBJECTIVES To determine the association between cytochrome p450 2B6 genotypes and efavirenz-based HIV treatment outcomes. DESIGN Observational cohort study of HIV-infected adults initiating efavirenz-based regimens in Botswana. METHODS The primary endpoint was a composite of death or loss to care or HIV RNA more than 25 copies/ml at 6 months. CYP2B6 516G>T and 983T>C genotyping was done with Taqman Open Array platform. Adverse experiences were measured by using the Subject Experience Questionnaire. Metabolism alleles were included in logistic regression models of the composite endpoint. RESULTS A total of 801 individuals included 406 (51%) men, median age 37 years, median baseline CD4 cell count 195 cells/μl, and plasma HIV RNA 4.9 log10 copies/ml. 288 (36%) reached the endpoint, including 34 (4%) deaths, 151 (19%) lost to care, 11 (1%) lost to the study, but alive and in care, and 92 (11%) with plasma HIV RNA more than 25 copies/ml. Metabolism variant alleles were common with 396 (49%) intermediate and 192 (24%) slow metabolizers. There were no statistically significant associations between metabolism and treatment endpoints. However, slower metabolism was associated with fewer adverse experiences. CONCLUSION Slow metabolism alleles were associated with lower efavirenz clearance but not any of the treatment endpoints. Slow efavirenz metabolism did not exacerbate central nervous system toxicity. These results should allay concern that slow efavirenz metabolism adversely impacts individuals in sub-Saharan African settings in which these alleles are common.
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Adehin A, Bolaji OO, Maggo S, Kennedy MA. Relationship between metabolic phenotypes and genotypes of CYP1A2 and CYP2A6 in the Nigerian population. Drug Metab Pers Ther 2017; 32:39-47. [PMID: 28231062 DOI: 10.1515/dmpt-2016-0041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 01/23/2017] [Indexed: 11/15/2022]
Abstract
BACKGROUND CYP1A2 and CYP2A6 are polymorphic drug-metabolising enzymes that are also implicated in the activation of procarcinogens in humans. Some of their alleles and haplotypes, often varied in prevalence across populations, are thought to influence activity despite the known contribution of environmental factors. This study assessed the potential influence of some genetic variants of CYP1A2 and CYP2A6 on metabolic phenotypes in Nigerians. METHODS Genomic DNA was extracted from blood samples of 100 healthy, unrelated subjects for whom CYP1A2 and CYP2A6 phenotypes had previously been determined, alongside an additional 80 other individuals for whom phenotype data were unavailable. The samples were screened for CYP1A2 (*1C,*1D,*1E,*1F, *3,*4,*6,*7) and CYP2A6 (*9,*11,*17) alleles using the Sequenom MassARRAY platform for some alleles and direct Sanger sequencing for others. The genetic data acquired were subsequently analysed for haplotypes and assessed for concordance with phenotypes. RESULTS All five CYP1A2 haplotypes (CYP1A2*1F, 1J, 1N, 1L, 1W) identified in the Nigerian population were not significantly predictive of metabolic phenotypes. Heterozygous CYP1A2*1J carriers and homozygous CYP1A2*1W carriers showed statistically insignificant decrease in CYP1A2 activity. The CYP2A6*9/*17 genotype was, however, significantly associated with the CYP2A6-poor metabolic phenotype, whereas CYP2A6*9 or CYP2A6*17 alone did not show any such association. CYP2A6*11 was not detected in the population. CONCLUSIONS Our findings suggest that CYP1A2 alleles or haplotypes were not predictive of metabolic phenotypes in the Nigerian population. Carriers of CYP2A6*9/*17 genotype are likely to be poor metabolisers of CYP2A6 substrates and may experience adverse reactions or poor efficacy while using drugs metabolised mainly by CYP2A6.
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Gallien S, Journot V, Loriot MA, Sauvageon H, Morlat P, Reynes J, Reliquet V, Chêne G, Molina JM. Cytochrome 2B6 polymorphism and efavirenz-induced central nervous system symptoms : a substudy of the ANRS ALIZE trial. HIV Med 2017; 18:537-545. [PMID: 28145050 DOI: 10.1111/hiv.12488] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2016] [Indexed: 01/11/2023]
Abstract
OBJECTIVES Single nucleotide polymorphisms in the cytochrome P450 (CYP) 2B6 gene have been associated with high interindividual variation in efavirenz pharmacokinetics. However, clinical data on the relationship of CYP2B6 polymorphisms with the occurrence of efavirenz-induced central nervous system (CNS) symptoms are limited. METHODS We analysed four polymorphisms in the CYP2B6 (516 G>T), CYP3A5 (6986 A>G) and ATP-binding cassette, sub-family B, member 1 (ABCB1) (2677 G>T/A and 3435 C>T) genes in HIV-infected adults virologically suppressed on a protease inhibitor-based regimen who switched to a regimen containing emtricitabine, didanosine and efavirenz in the setting of the ANRS ALIZE trial. Kaplan-Meier methods and Cox regression analysis were used to investigate their association with efavirenz plasma levels and CNS events up to 48 months after switching. RESULTS In total, 191 patients with a median age of 41 years, who were 87% male and 85% Caucasian, were enrolled in the study. Variant allelic frequencies were 0.49, 0.93, 0.59 and 0.63 for CYP2B6 516, CYP3A5 392, ABCB1 2677 and ABCB1 3435, respectively. The median efavirenz plasma concentration (MEPC) was 2.2 mg/L [interquartile range (IQR) 1.7-2.8 mg/L] and was significantly higher in patients with the deficient CYP2B6 516T. Overall, 242 CNS events were reported in 104 individuals (54%). No correlation was found between MEPC and CNS events. The occurrence of a first CNS event was lower in patients with the CYP2B6 516 G/G genotype vs. CYP2B6 516 T genotypes [50% (IQR: 40-60%) vs. 66% (IQR: 56-75%), respectively; P = 0.02]. In an adjusted Cox regression model, there was a tendency towards a higher risk of a first CNS event among carriers of the variant CYP2B6 516 T allele (relative risk 1.4 [95% CI, 0.99-2.1]; P?=?.06), compared with noncarriers. CONCLUSIONS The deficient CYP2B6 516 T allele is associated with higher efavirenz plasma drug levels and more frequent CNS-related symptoms.
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Affiliation(s)
- S Gallien
- Sorbonne Paris Cité, Université Paris Diderot Paris 7, Paris, France.,Assistance Publique-Hôpitaux de Paris (AP-HP), Service de Maladies Infectieuses, Hôpital Saint-Louis, Paris, France
| | | | - M-A Loriot
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,INSERM UMR_S1147, Centre Universitaire des Saints-Pères, Paris, France.,Assistance Publique-Hôpitaux de Paris (AP-HP), Service de Biochimie, Hôpital Européen Georges Pompidou, Paris, France
| | - H Sauvageon
- Assistance Publique-Hôpitaux de Paris (AP-HP), Pharmacie, Hôpital Saint-Louis, Paris, France
| | - P Morlat
- Service de médecine interne, Hôpital Saint-André, Bordeaux, France
| | - J Reynes
- Département des Maladies Infectieuses et Tropicales, Centre Hospitalier Universitaire Montpellier, Montpellier, France
| | - V Reliquet
- Service de Maladies Infectieuses, CHU Nantes, Nantes, France
| | - G Chêne
- INSERM U1219, Bordeaux, France
| | - J-M Molina
- Sorbonne Paris Cité, Université Paris Diderot Paris 7, Paris, France.,Assistance Publique-Hôpitaux de Paris (AP-HP), Service de Maladies Infectieuses, Hôpital Saint-Louis, Paris, France
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Queiroz MAF, Laurentino RV, da Silva Graça Amoras E, Araújo MSMD, Gomes STM, Lima SS, Vallinoto ACR, de Oliveira Guimarães Ishak M, Ishak R, Machado LFA. The CYP2B6 G516T polymorphism influences CD4 + T-cell counts in HIV-positive patients receiving antiretroviral therapy in an ethnically diverse region of the Amazon. Int J Infect Dis 2016; 55:4-10. [PMID: 27940179 DOI: 10.1016/j.ijid.2016.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 11/30/2016] [Accepted: 12/02/2016] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES Cytochrome P450 (CYP) enzyme polymorphisms seem to significantly influence the variability of the responses to certain antiretroviral drugs and their toxicity levels. The objective of this study was to evaluate the influence of the CYP2B6 G516T polymorphism on hepatic, renal, immunological, and viral marker changes in HIV-1-positive patients receiving treatment in an ethnically diverse region of the Amazon. METHODS CYP2B6 G516T genotyping was performed by real-time PCR (RT-PCR) in samples from 185 patients. Urea, creatinine, aspartate aminotransferase (AST), alanine aminotransferase (ALT), CD4+/CD8+ T-cell counts, and HIV-1 plasma viral load were measured. RESULTS The polymorphic CYP2B6 G516T allele frequency was 0.36, which is different from the frequencies in other ethnic groups. The polymorphic genotype was associated with changes in the urea and ALT levels, although the median values were within the normal range. The TT genotype was also associated with significantly lower CD4+ T-cell counts in patients using efavirenz. CONCLUSIONS The CYP2B6 G516T polymorphism seems to affect the response to efavirenz treatment by reducing CD4+ T-cell counts in patients with a high degree of miscegenation who use this antiretroviral agent.
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Affiliation(s)
- Maria Alice Freitas Queiroz
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | - Rogério Valois Laurentino
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | - Ednelza da Silva Graça Amoras
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | | | - Samara Tatielle Monteiro Gomes
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | - Sandra Souza Lima
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | - Antonio Carlos Rosário Vallinoto
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | - Marluísa de Oliveira Guimarães Ishak
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | - Ricardo Ishak
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil
| | - Luiz Fernando Almeida Machado
- Laboratório de Virologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Correa s/no., Guamá, CEP 66.075-110, Belém, Pará, Brazil.
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Céspedes-Garro C, Naranjo MEG, Rodrigues-Soares F, LLerena A, Duconge J, Montané-Jaime LK, Roblejo H, Fariñas H, Campos MDLA, Ramírez R, Serrano V, Villagrán CI, Peñas-LLedó EM. Pharmacogenetic research activity in Central America and the Caribbean: a systematic review. Pharmacogenomics 2016; 17:1707-1724. [PMID: 27633613 DOI: 10.2217/pgs-2016-0053] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
AIM The present review was aimed at analyzing the pharmacogenetic scientific activity in Central America and the Caribbean. MATERIALS & METHODS A literature search for pharmacogenetic studies in each country of the region was conducted on three databases using a list of the most relevant pharmacogenetic biomarkers including 'phenotyping probe drugs' for major drug metabolizing enzymes. The review included 132 papers involving 47 biomarkers and 35,079 subjects (11,129 healthy volunteers and 23,950 patients). RESULTS The country with the most intensive pharmacogenetic research was Costa Rica. The most studied medical therapeutic area was oncology, and the most investigated biomarkers were CYP2D6 and HLA-A/B. Conclusion: Research activity on pharmacogenetics in Central American and the Caribbean populations is limited or absent. Therefore, strategies to promote effective collaborations, and foster interregional initiatives and research efforts among countries from the region could help for the rational clinical implementation of pharmacogenetics and personalized medicine.
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Affiliation(s)
- Carolina Céspedes-Garro
- CICAB Clinical Research Centre, Extremadura University Hospital & Medical School, Badajoz, Spain.,RIBEF Ibero-American Network of Pharmacogenetics & Pharmacogenomics.,Teaching & Research Department, Genetics Section, School of Biology, University of Costa Rica, San José, Costa Rica
| | - María-Eugenia G Naranjo
- CICAB Clinical Research Centre, Extremadura University Hospital & Medical School, Badajoz, Spain.,RIBEF Ibero-American Network of Pharmacogenetics & Pharmacogenomics
| | - Fernanda Rodrigues-Soares
- RIBEF Ibero-American Network of Pharmacogenetics & Pharmacogenomics.,Departamento de Biologia Geral, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Adrián LLerena
- CICAB Clinical Research Centre, Extremadura University Hospital & Medical School, Badajoz, Spain.,RIBEF Ibero-American Network of Pharmacogenetics & Pharmacogenomics
| | - Jorge Duconge
- RIBEF Ibero-American Network of Pharmacogenetics & Pharmacogenomics.,Pharmaceutical Sciences Department, School of Pharmacy, Medical Sciences Campus, University of Puerto Rico, San Juan, Puerto Rico
| | - Lazara K Montané-Jaime
- Pharmacology Unit Department of Paraclinical Sciences, Faculty of Medical Sciences, The University of West Indies, St Augustine, Trinidad & Tobago
| | - Hilda Roblejo
- RIBEF Ibero-American Network of Pharmacogenetics & Pharmacogenomics.,Teaching & Research Department, National Center of Medical Genetics, Havana, Cuba
| | - Humberto Fariñas
- CICAB Clinical Research Centre, Extremadura University Hospital & Medical School, Badajoz, Spain
| | - María de Los A Campos
- Secretaría Ejecutiva del Consejo de Ministros de Salud de Centroamérica y República Dominicana, Ciudad Merliot, El Salvador
| | - Ronald Ramírez
- RIBEF Ibero-American Network of Pharmacogenetics & Pharmacogenomics.,Facultad de Medicina, UNAN Universidad Autónoma Nacional de Nicaragua, León, Nicaragua
| | - Víctor Serrano
- RIBEF Ibero-American Network of Pharmacogenetics & Pharmacogenomics.,CIIMET Centro de Investigación e Información de Medicamentos y Tóxicos, Facultad de Medicina, Universidad de Panamá, Panamá, Panamá
| | - Carmen I Villagrán
- RIBEF Ibero-American Network of Pharmacogenetics & Pharmacogenomics.,Facultad de Ciencias Médicas, Dirección de Investigación, Universidad de San Carlos de Guatemala, Guatemala
| | - Eva M Peñas-LLedó
- CICAB Clinical Research Centre, Extremadura University Hospital & Medical School, Badajoz, Spain.,RIBEF Ibero-American Network of Pharmacogenetics & Pharmacogenomics
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Evans J, Swart M, Soko N, Wonkam A, Huzair F, Dandara C. A Global Health Diagnostic for Personalized Medicine in Resource-Constrained World Settings: A Simple PCR-RFLP Method for Genotyping CYP2B6 g.15582C>T and Science and Policy Relevance for Optimal Use of Antiretroviral Drug Efavirenz. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2016; 19:332-8. [PMID: 26415139 DOI: 10.1089/omi.2015.0039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The use of pharmacogenomics (PGx) knowledge in treatment of individual patients is becoming a common phenomenon in the developed world. However, poorly resourced countries have thus far been constrained for three main reasons. First, the cost of whole genome sequencing is still considerably high in comparison to other (non-genomics) diagnostics in the developing world where both science and social dynamics create a dynamic and fragile healthcare ecosystem. Second, studies correlating genomic differences with drug pharmacokinetics and pharmacodynamics have not been consistent, and more importantly, often not indexed to impact on societal end-points, beyond clinical practice. Third, ethics regulatory frames over PGx testing require improvements based on nested accountability systems and in ways that address the user community needs. Thus, CYP2B6 is a crucial enzyme in the metabolism of antiretroviral drugs, efavirenz and nevirapine. More than 40 genetic variants have been reported, but only a few contribute to differences in plasma EFV and NVP concentrations. The most widely reported CYP2B6 variants affecting plasma drug levels include c.516G>T, c.983T>C, and to a lesser extent, g.15582C>T, which should be considered in future PGx tests. While the first two variants are easily characterized, the g.15582C>T detection has been performed primarily by sequencing, which is costly, labor intensive, and requires access to barely available expertise in the developing world. We report here on a simple, practical PCR-RFLP method with vast potentials for use in resource-constrained world regions to detect the g.15582C>T variation among South African and Cameroonian persons. The effects of CYP2B6 g.15582C>T on plasma EFV concentration were further evaluated among HIV/AIDS patients. We report no differences in the frequency of the g.15582T variant between the South African (0.08) and Cameroonian (0.06) groups, which are significantly lower than reported in Asians (0.39) and Caucasians (0.31). The g.15582C/T and T/T genotypes were associated with significantly reduced EFV levels (p=0.006). This article additionally presents the policy relevance of the PGX global health diagnostics and therefore, collectively makes an original interdisciplinary contribution to the field of integrative biology and personalized medicine in developing world. Such studies are, in fact, broadly important because resource-constrained regions exist not only in developing world but also in major geographical parts of the G20 nations and the developed countries.
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Affiliation(s)
- Jonathan Evans
- 1 Pharmacogenetics and Cancer Research Group, Division of Human Genetics, Department of Clinical Laboratory Sciences and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town , Cape Town, South Africa
| | - Marelize Swart
- 1 Pharmacogenetics and Cancer Research Group, Division of Human Genetics, Department of Clinical Laboratory Sciences and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town , Cape Town, South Africa
| | - Nyarai Soko
- 1 Pharmacogenetics and Cancer Research Group, Division of Human Genetics, Department of Clinical Laboratory Sciences and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town , Cape Town, South Africa
| | - Ambroise Wonkam
- 1 Pharmacogenetics and Cancer Research Group, Division of Human Genetics, Department of Clinical Laboratory Sciences and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town , Cape Town, South Africa
| | - Farah Huzair
- 2 Science, Technology and Innovation Studies, School of Social and Political Science, University of Edinburgh , Edinburgh, United Kingdom
| | - Collet Dandara
- 1 Pharmacogenetics and Cancer Research Group, Division of Human Genetics, Department of Clinical Laboratory Sciences and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town , Cape Town, South Africa
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Röhrich CR, Drögemöller BI, Ikediobi O, van der Merwe L, Grobbelaar N, Wright GE, McGregor N, Warnich L. CYP2B6*6 and CYP2B6*18 Predict Long-Term Efavirenz Exposure Measured in Hair Samples in HIV-Positive South African Women. AIDS Res Hum Retroviruses 2016; 32:529-38. [PMID: 26655325 DOI: 10.1089/aid.2015.0048] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Long-term exposure to efavirenz (EFV) measured in hair samples may predict response to antiretroviral treatment (ART). Polymorphisms in CYP2B6 are known to alter EFV levels. The aim of this study was to assess the relationship between CYP2B6 genotype, EFV levels measured in hair, and virological outcomes on ART in a real-world setting. We measured EFV levels in hair from HIV-positive South African females who had been receiving EFV-based treatment for at least 3 months from the South African Black (SAB) (n = 81) and Cape Mixed Ancestry (CMA) (n = 53) populations. Common genetic variation in CYP2B6 was determined in 15 individuals from each population using bidirectional Sanger sequencing. Prioritized variants (n = 16) were subsequently genotyped in the entire patient cohort (n = 134). The predictive value of EFV levels in hair and selected variants in CYP2B6 on virological treatment outcomes was assessed. Previously described alleles (CYP2B6*2, CYP2B6*5, CYP2B6*6, CYP2B6*17, and CYP2B6*18), as well as two novel alleles (CYP2B6*31 and CYP2B6*32), were detected in this study. Compared to noncarriers, individuals homozygous for CYP2B6*6 had ∼109% increased EFV levels in hair (p = .016) and CYP2B6*18 heterozygotes demonstrated 82% higher EFV hair levels (p = .0006). This study confirmed that alleles affecting CYP2B6 metabolism and subsequent EFV exposure are present at significant frequencies in both the SAB and CMA populations. Furthermore, this study demonstrated that the use of hair samples for testing EFV concentrations may be a useful tool in determining long-term drug exposure in resource-limited countries.
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Affiliation(s)
- Carola R. Röhrich
- Department of Genetics, Stellenbosch University, Stellenbosch, South Africa
| | | | - Ogechi Ikediobi
- Departments of Pharmacy, University of California San Francisco, UCSF, San Francisco, California
| | - Lize van der Merwe
- Department of Molecular Biology and Human Genetics, Stellenbosch University, Tygerberg, South Africa
- Department of Statistics, University of Western Cape, Bellville, South Africa
| | | | - Galen E.B. Wright
- Department of Genetics, Stellenbosch University, Stellenbosch, South Africa
| | - Nathaniel McGregor
- Department of Genetics, Stellenbosch University, Stellenbosch, South Africa
- Department of Psychiatry, Stellenbosch University, Tygerberg, South Africa
| | - Louise Warnich
- Department of Genetics, Stellenbosch University, Stellenbosch, South Africa
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Arab-Alameddine M, Décosterd LA, Buclin T, Telenti A, Csajka C. Antiretroviral drug toxicity in relation to pharmacokinetics, metabolic profile and pharmacogenetics. Expert Opin Drug Metab Toxicol 2016; 7:609-22. [PMID: 21500966 DOI: 10.1517/17425255.2011.562891] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Besides therapeutic effectiveness, drug tolerability is a key issue for treatments that must be taken indefinitely. Given the high prevalence of toxicity in HIV therapy, the factors implicated in drug-induced morbidities should be identified in order to improve the safety, tolerability and adherence to the treatments. Current approaches have focused almost exclusively on parent drug concentrations; whereas recent evidence suggests that drug metabolites resulting from complex genetic and environmental influences can also contribute to treatment outcome. Pharmacogenetic variations have shown to play a relevant role in the variability observed in antiretroviral drug exposure, clinical response and sometimes toxicity. The integration of pharmacokinetic, pharmacogenetic and metabolic determinants will more probably address current therapeutic needs in patients. AREAS COVERED This review offers a concise description of three classes of antiretroviral drugs. The review looks at the metabolic profile of these drugs and gives a comprehensive summary of the existing literature on the influence of pharmacogenetics on their pharmacokinetics and metabolic pathways, and the associated drug or metabolite toxicity. EXPERT OPINION Due to the high prevalence of toxicity and the related risk of low adherence to the treatments, association of kinetic, genetic and metabolic markers predictive of therapeutic or toxicity outcomes could represent a more complete approach for optimizing antiretroviral therapy.
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Affiliation(s)
- Mona Arab-Alameddine
- Department of Clinical Pharmacology and Toxicology, University Hospital and University of Lausanne, Beaumont, Lausanne, Switzerland
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Yang HC, Chu SK, Huang CL, Kuo HW, Wang SC, Liu SW, Ho IK, Liu YL. Genome-Wide Pharmacogenomic Study on Methadone Maintenance Treatment Identifies SNP rs17180299 and Multiple Haplotypes on CYP2B6, SPON1, and GSG1L Associated with Plasma Concentrations of Methadone R- and S-enantiomers in Heroin-Dependent Patients. PLoS Genet 2016; 12:e1005910. [PMID: 27010727 PMCID: PMC4806848 DOI: 10.1371/journal.pgen.1005910] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 02/09/2016] [Indexed: 01/25/2023] Open
Abstract
Methadone maintenance treatment (MMT) is commonly used for controlling opioid dependence, preventing withdrawal symptoms, and improving the quality of life of heroin-dependent patients. A steady-state plasma concentration of methadone enantiomers, a measure of methadone metabolism, is an index of treatment response and efficacy of MMT. Although the methadone metabolism pathway has been partially revealed, no genome-wide pharmacogenomic study has been performed to identify genetic determinants and characterize genetic mechanisms for the plasma concentrations of methadone R- and S-enantiomers. This study was the first genome-wide pharmacogenomic study to identify genes associated with the plasma concentrations of methadone R- and S-enantiomers and their respective metabolites in a methadone maintenance cohort. After data quality control was ensured, a dataset of 344 heroin-dependent patients in the Han Chinese population of Taiwan who underwent MMT was analyzed. Genome-wide single-locus and haplotype-based association tests were performed to analyze four quantitative traits: the plasma concentrations of methadone R- and S-enantiomers and their respective metabolites. A significant single nucleotide polymorphism (SNP), rs17180299 (raw p = 2.24 × 10−8), was identified, accounting for 9.541% of the variation in the plasma concentration of the methadone R-enantiomer. In addition, 17 haplotypes were identified on SPON1, GSG1L, and CYP450 genes associated with the plasma concentration of methadone S-enantiomer. These haplotypes accounted for approximately one-fourth of the variation of the overall S-methadone plasma concentration. The association between the S-methadone plasma concentration and CYP2B6, SPON1, and GSG1L were replicated in another independent study. A gene expression experiment revealed that CYP2B6, SPON1, and GSG1L can be activated concomitantly through a constitutive androstane receptor (CAR) activation pathway. In conclusion, this study revealed new genes associated with the plasma concentration of methadone, providing insight into the genetic foundation of methadone metabolism. The results can be applied to predict treatment responses and methadone-related deaths for individualized MMTs. Methadone maintenance treatment (MMT), among the most effective therapies for heroin-dependent patients, reduces craving and withdrawal symptoms, increases treatment compliance, and improves the quality of life of patients. The plasma concentration of methadone is a primary index for quantifying and determining therapy responses to MMT. This study was the first whole-genome pharmacogenomic study on MMT to locate genomic regions associated with the plasma concentration of methadone. The analysis identified a single nucleotide polymorphism (SNP) marker (rs17180299) and 17 haplotypes on the SPON1, GSG1L, and CYP450 genes, including CYP2B6 significantly associated with the plasma concentrations of methadone enantiomers. The identified genetic variations accounted for approximately 10% and 25% of the variations in plasma concentrations of methadone R- and S-enantiomers, respectively. The identified genetic variations have afforded insight into the genetic mechanism of the metabolism of MMT, and have potential to pave the way towards individualized MMTs for heroin-dependent patients.
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Affiliation(s)
- Hsin-Chou Yang
- Institute of Statistical Science, Academia Sinica, Taipei, Taiwan
- Bioinformatics Program, Taiwan International Graduate Program, Institute of Information Science, Academia Sinica, Taipei, Taiwan
- Institute of Public Health, National Yang Ming University, Taipei, Taiwan
- Department of Statistics, National Cheng-Kung University, Tainan, Taiwan
- School of Public Health, National Defense Medical Center, Taipei, Taiwan
| | - Shih-Kai Chu
- Institute of Statistical Science, Academia Sinica, Taipei, Taiwan
- Bioinformatics Program, Taiwan International Graduate Program, Institute of Information Science, Academia Sinica, Taipei, Taiwan
- Institute of Biomedical Informatics, National Yang-Ming University, Taipei, Taiwan
| | - Chieh-Liang Huang
- Center for Drug Abuse and Addiction, China Medical University Hospital, Taichung, Taiwan
- School of Medicine, China Medical University, Taichung, Taiwan
| | - Hsiang-Wei Kuo
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli County, Taiwan
| | - Sheng-Chang Wang
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli County, Taiwan
| | - Sheng-Wen Liu
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli County, Taiwan
| | - Ing-Kang Ho
- Center for Drug Abuse and Addiction, China Medical University Hospital, Taichung, Taiwan
| | - Yu-Li Liu
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli County, Taiwan
- Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
- * E-mail:
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15
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Pinillos F, Dandara C, Swart M, Strehlau R, Kuhn L, Patel F, Coovadia A, Abrams E. Case report: Severe central nervous system manifestations associated with aberrant efavirenz metabolism in children: the role of CYP2B6 genetic variation. BMC Infect Dis 2016; 16:56. [PMID: 26831894 PMCID: PMC4735961 DOI: 10.1186/s12879-016-1381-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 01/25/2016] [Indexed: 01/11/2023] Open
Abstract
Background Efavirenz, widely used as part of antiretroviral drug regimens in the treatment of paediatric human immunodeficiency virus infection, has central nervous system side effects. We describe four children presenting with serious, persistent central nervous system adverse events who were found to have elevated plasma efavirenz concentrations as a result of carrying CYP2B6 single nucleotide polymorphisms, known to play a role in the metabolism of EFV. None of the children had a CYP2B6 wildtype haplotype. We believe this is the first case of cerebellar dysfunction associated with efavirenz use to be described in children. Case presentation Four black African children, between the ages of 4 and 8 years presenting between 1 and 20 months post-efavirenz initiation, are described. Cerebellar dysfunction, generalised seizures and absence seizures were the range of presenting abnormalities. Plasma efavirenz levels ranged from 20-60 mg/L, 5–15 times the upper limit of the suggested reference range. All abnormal central nervous system manifestations abated after efavirenz discontinuation. Conclusion Efavirenz toxicity should always be considered in human immunodeficiency virus-infected children with unexplained central nervous system abnormalities. Our findings further our understanding of the impact of genetic variants on antiretroviral pharmacokinetics in children across various ethnic groups. Screening for potential EFV-toxicity based on the CYP2B6 c.516 SNP alone, may not be adequate.
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Affiliation(s)
- Francoise Pinillos
- Empilweni Services and Research Unit (ESRU), Rahima Moosa Mother and Child Hospital, Department of Paediatrics and Child Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Collet Dandara
- Pharmacogenetics and Cancer Research Group, Division of Human Genetics, Department of Pathology & Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Marelize Swart
- Pharmacogenetics and Cancer Research Group, Division of Human Genetics, Department of Pathology & Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Renate Strehlau
- Empilweni Services and Research Unit (ESRU), Rahima Moosa Mother and Child Hospital, Department of Paediatrics and Child Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Louise Kuhn
- Gertrude H. Sergievsky Center, College of Physicians and Surgeons; and Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA
| | - Faeezah Patel
- Empilweni Services and Research Unit (ESRU), Rahima Moosa Mother and Child Hospital, Department of Paediatrics and Child Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Ashraf Coovadia
- Empilweni Services and Research Unit (ESRU), Rahima Moosa Mother and Child Hospital, Department of Paediatrics and Child Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Elaine Abrams
- ICAP, Mailman School of Public Health, and College of Physicians & Surgeons Columbia University, 722 W168th street, New York, NY, 10032, USA.
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Direct sequencing and comprehensive screening of genetic polymorphisms on CYP2 family genes (CYP2A6, CYP2B6, CYP2C8, and CYP2E1) in five ethnic populations. Arch Pharm Res 2014; 38:115-28. [DOI: 10.1007/s12272-014-0348-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 01/27/2014] [Indexed: 01/11/2023]
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Lawn SD, Meintjes G, McIlleron H, Harries AD, Wood R. Management of HIV-associated tuberculosis in resource-limited settings: a state-of-the-art review. BMC Med 2013; 11:253. [PMID: 24295487 PMCID: PMC4220801 DOI: 10.1186/1741-7015-11-253] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 11/07/2013] [Indexed: 01/08/2023] Open
Abstract
The HIV-associated tuberculosis (TB) epidemic remains a huge challenge to public health in resource-limited settings. Reducing the nearly 0.5 million deaths that result each year has been identified as a key priority. Major progress has been made over the past 10 years in defining appropriate strategies and policy guidelines for early diagnosis and effective case management. Ascertainment of cases has been improved through a twofold strategy of provider-initiated HIV testing and counseling in TB patients and intensified TB case finding among those living with HIV. Outcomes of rifampicin-based TB treatment are greatly enhanced by concurrent co-trimoxazole prophylaxis and antiretroviral therapy (ART). ART reduces mortality across a spectrum of CD4 counts and randomized controlled trials have defined the optimum time to start ART. Good outcomes can be achieved when combining TB treatment with first-line ART, but use with second-line ART remains challenging due to pharmacokinetic drug interactions and cotoxicity. We review the frequency and spectrum of adverse drug reactions and immune reconstitution inflammatory syndrome (IRIS) resulting from combined treatment, and highlight the challenges of managing HIV-associated drug-resistant TB.
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Affiliation(s)
- Stephen D Lawn
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
- The Desmond Tutu HIV Centre, Institute for Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Graeme Meintjes
- Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Clinical Infectious Diseases Research Initiative, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Helen McIlleron
- Division of Clinical Pharmacology, Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Anthony D Harries
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
- International Union against Tuberculosis and Lung Disease (The Union), Paris, France
| | - Robin Wood
- The Desmond Tutu HIV Centre, Institute for Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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Correlates of efavirenz exposure in Chilean patients affected with human immunodeficiency virus reveals a novel association with a polymorphism in the constitutive androstane receptor. Ther Drug Monit 2013; 35:78-83. [PMID: 23172109 DOI: 10.1097/ftd.0b013e318274197e] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE To explore the effect of demographics and single-nucleotide polymorphisms in cytochrome P450 (CYP) 2B6, 2A6, UDP-glucuronosyltransferase (UGT) 2B7, and the constitutive androstane receptor (CAR) genes on efavirenz pharmacokinetics in a Chilean cohort affected with human immunodeficiency virus. METHODS Timed plasma samples obtained throughout the dosing interval were analyzed for efavirenz concentrations with liquid chromatography/tandem mass spectrometry. DNA from whole-blood samples was used for genetic analysis. Data were analyzed using a Mann-Whitney statistical test; furthermore, a Pearson or Spearman correlation was used. A multivariate analysis was then conducted using multiple linear regression by best subset analysis. RESULTS Overall 219 patients were included, 208 patients had measurable efavirenz levels and available genetic samples. The overall median (interquartile range) of efavirenz concentration was 2.6 (2.1-3.7) mcg/mL. In multivariate regression analysis, CYP2B6 516G>T (P < 0.0001) and CAR rs2307424 C>T (P = 0.002) were significantly related to efavirenz plasma concentrations. CONCLUSION This novel association between CAR rs2307424 and efavirenz plasma concentrations now requires validation in other cohorts.
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Echenique IA, Rich JD. EFV/FTC/TDF-associated hepatotoxicity: a case report and review. AIDS Patient Care STDS 2013; 27:493-7. [PMID: 23937548 DOI: 10.1089/apc.2013.0008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The fixed-dose combination efavirenz, emtricitabine, and tenofovir (EFV/FTC/TDF) is a first-line agent for the treatment of HIV. We report the case of a 40-year-old female with a history of HIV acquired through heterosexual contact who initiated EFV/FTC/TDF. Hepatitis B and C serologies were negative, CD4 cell count was 253 cells per cubic millimeter (15.8%), and HIV viral load was 67,373 copies per milliliter. Eight months later she developed transaminitis and severe right upper quadrant pain. Neither illicit drug abuse nor hepatotoxic medication such as acetaminophen was reported. After evaluation including negative acute viral hepatitis studies, EFV/FTC/TDF was discontinued; both her transaminitis and pain resolved. Hepatotoxicity is most often associated with efavirenz. Rarely, fulminant hepatic failure occurs. Efavirenz-related hepatotoxicity is thought to result from a cellular self-digestion process known as autophagy. This is the first report to our knowledge of EFV/FTC/TDF-related hepatotoxicity.
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Affiliation(s)
- Ignacio A. Echenique
- Division of Infectious Diseases, Feinberg School of Medicine of Northwestern University, Chicago, Illinois
| | - Josiah D. Rich
- Division of Infectious Diseases, The Miriam Hospital, Alpert Medical School of Brown University, Providence, Rhode Island
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Effects of rifampin-based antituberculosis therapy on plasma efavirenz concentrations in children vary by CYP2B6 genotype. AIDS 2013; 27:1933-40. [PMID: 24180002 DOI: 10.1097/qad.0b013e328360dbb4] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES An efavirenz-based antiretroviral therapy (ART) regimen is preferred for children more than 3 years of age with tuberculosis. However, rifampin, a key component of antituberculosis therapy, induces CYP2B6. An increased dose of efavirenz is recommended in adults weighing more than 50 kg who require rifampin, but there is scant information in children being treated for tuberculosis. DESIGN Plasma efavirenz concentrations were compared in 40 children during concomitant treatment for tuberculosis and HIV-1, after stopping rifampicin, and in a control group of children without tuberculosis. Associations with antituberculosis treatment, metabolizer genotype (based on CYP2B6 516G→T, 983T→C, and 15582C→T), weight, and time after dose were evaluated. RESULTS Compared to children with extensive metabolizer genotypes, efavirenz concentrations were increased 1.42-fold (95% confidence interval, CI 0.94–2.15) and 2.85-fold (95% CI 1.80–4.52) in children with intermediate and slow metabolizer genotypes, respectively. Concomitant antituberculosis treatment increased efavirenz concentrations 1.49-fold (95% CI 1.10–2.01) in children with slow metabolizer genotypes, but did not affect efavirenz concentrations in extensive or intermediate metabolizer genotypes. After adjustment for dose/kg, each kilogram of weight was associated with a 2.8% (95% CI 0.9–4.7) decrease in efavirenz concentrations. Despite higher milligram per kilogram doses, a higher proportion of children in the lowest weight band (10–13.9 kg) had efavirenz concentrations less than 1.0 mg/l than larger children. CONCLUSION Antituberculosis treatment was not associated with reduced efavirenz concentrations in children, which does not support increased efavirenz doses. Children with slow metabolizer genotype have increased efavirenz concentrations during antituberculosis treatment, likely due to isoniazid inhibiting enzymes involved in accessory metabolic pathways for efavirenz.
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21
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Sánchez Martín A, Cabrera Figueroa S, Cruz Guerrero R, Hurtado LP, Hurlé ADG, Carracedo Álvarez Á. Impact of pharmacogenetics on CNS side effects related to efavirenz. Pharmacogenomics 2013; 14:1167-78. [DOI: 10.2217/pgs.13.111] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Aim: This article evaluates which genetic factors are involved in CNS toxicity related to long-term treatment with efavirenz (EFV) standard doses and their relationship with plasma concentrations. Patients & methods: A total of 119 HIV-positive patients, in which 1350 EFV plasma concentrations, 68 SNPs and 14 EFV-related adverse effects (AEs) were analyzed. Results: Overall, 32.77% of patients reported CNS toxicity and 8.40% had concentrations above the therapeutic range. A correlation was mainly found between patients with global CNS AEs and high EFV maximum steady-state plasma concentration (p = 1.47 × 10-6). A preliminary analysis confirmed that CYP2B6*6 (516G>T and 785A>G) was the most highly correlated (p = 0.005) with AEs and high plasma concentrations. In a second analysis adjusting for maximum steady-state plasma concentration, suggestive genetic associations were found between BCRP 421C>A, MRP1 816G>A, 5-HT2A 102C>T and different AEs. Conclusion: The finding of the involvement of these SNPs in EFV toxicity opens the door for further studies to confirm their validity and for their application in the future clinical practice. Original submitted 18 February 2013; Revision submitted 17 May 2013
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Affiliation(s)
| | | | - Raquel Cruz Guerrero
- Fundación Galega Medicina Xenómica y Centro de Investigación Biomédica en Red de Enfermedades Raras – USC– CIMUS – IDIS, Spain
| | - Liliana Porras Hurtado
- Fundación Galega Medicina Xenómica (SERGAS)-CeGen-University of Santiago de Compostela, Spain
- ESE Salud Pereira, Colombia
| | | | - Ángel Carracedo Álvarez
- Fundación Galega Medicina Xenómica (SERGAS)-CeGen-University of Santiago de Compostela, Spain
- USC – Centro de investigación biomédica en red de Enfermedades Raras, Spain
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PharmGKB summary: very important pharmacogene information for cytochrome P-450, family 2, subfamily A, polypeptide 6. Pharmacogenet Genomics 2013; 22:695-708. [PMID: 22547082 DOI: 10.1097/fpc.0b013e3283540217] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Cristofoletti R, Nair A, Abrahamsson B, Groot DW, Kopp S, Langguth P, Polli JE, Shah VP, Dressman JB. Biowaiver monographs for immediate release solid oral dosage forms: efavirenz. J Pharm Sci 2012; 102:318-29. [PMID: 23175470 DOI: 10.1002/jps.23380] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 10/12/2012] [Accepted: 10/30/2012] [Indexed: 11/07/2022]
Abstract
Literature data pertaining to the decision to allow a waiver of in vivo bioequivalence testing for the approval of immediate-release (IR) solid oral dosage forms containing efavirenz as the only active pharmaceutical ingredient (API) are reviewed. Because of lack of conclusive data about efavirenz's permeability and its failure to comply with the "high solubility" criteria according to the Biopharmaceutics Classification System (BCS), the API can be classified as BCS Class II/IV. In line with the solubility characteristics, the innovator product does not meet the dissolution criteria for a "rapidly dissolving product." Furthermore, product variations containing commonly used excipients or in the manufacturing process have been reported to impact the rate and extent of efavirenz absorption. Despite its wide therapeutic index, subtherapeutic levels of efavirenz can lead to treatment failure and also facilitate the emergence of efavirenz-resistant mutants. For all these reasons, a biowaiver for IR solid oral dosage forms containing efavirenz as the sole API is not scientifically justified for reformulated or multisource drug products.
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Affiliation(s)
- Rodrigo Cristofoletti
- Brazilian Health Surveillance Agency (Anvisa), Division of Bioequivalence, Londrina State University, Londrina, Brazil
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Dooley KE, Park JG, Swindells S, Allen R, Haas DW, Cramer Y, Aweeka F, Wiggins I, Gupta A, Lizak P, Qasba S, van Heeswijk R, Flexner C. Safety, tolerability, and pharmacokinetic interactions of the antituberculous agent TMC207 (bedaquiline) with efavirenz in healthy volunteers: AIDS Clinical Trials Group Study A5267. J Acquir Immune Defic Syndr 2012; 59:455-62. [PMID: 22126739 PMCID: PMC3302922 DOI: 10.1097/qai.0b013e3182410503] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Drug-drug interactions complicate management of coinfection with HIV-1 and Mycobacterium tuberculosis. Bedaquiline (formerly TMC207), an investigational agent for the treatment of tuberculosis, is metabolized by cytochrome P450 (CYP) 3A which may be induced by the antiretroviral drug efavirenz. METHODS This was a phase 1 pharmacokinetic drug interaction trial. Each healthy volunteer received two 400 mg doses of bedaquiline, the first alone and the second with concomitant steady-state efavirenz. Plasma pharmacokinetic sampling for bedaquiline and its N-monodesmethyl metabolite was performed over 14 days after each bedaquiline dose. Steady-state efavirenz pharmacokinetics were also determined. Efavirenz metabolizer status was based on CYP2B6 composite 516/983 genotype. RESULTS Thirty-three of 37 enrolled subjects completed the study. Geometric mean of ratios for bedaquiline with efavirenz versus bedaquiline alone were 0.82 [90% confidence interval (CI): 0.75 to 0.89] for the 14-day area under the concentration-time curve (AUC0-336 h) and 1.00 (90% CI: 0.88 to 1.13) for the maximum concentration (Cmax). For N-monodesmethyl metabolite, the geometric mean of ratios was 1.07 (90% CI: 0.97 to 1.19) for AUC0-336 h and 1.89 (90% CI: 1.66 to 2.15) for C(max). There were no grade 3 or 4 clinical adverse events. One subject developed asymptomatic grade 3 serum transaminase elevation, prompting study drug discontinuation. Efavirenz concentrations stratified by CYP2B6 genotype were similar to historical data. CONCLUSIONS Single-dose bedaquiline was well tolerated alone and with steady-state efavirenz. The effect of efavirenz on bedaquiline concentrations is unlikely to be clinically significant.
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Affiliation(s)
- Kelly E Dooley
- Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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Li J, Menard V, Benish RL, Jurevic RJ, Guillemette C, Stoneking M, Zimmerman PA, Mehlotra RK. Worldwide variation in human drug-metabolism enzyme genes CYP2B6 and UGT2B7: implications for HIV/AIDS treatment. Pharmacogenomics 2012; 13:555-70. [PMID: 22462748 PMCID: PMC3390746 DOI: 10.2217/pgs.11.160] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
AIM Hepatic enzymes, CYP2B6 and UGT2B7 play a major role in the metabolism of the widely used antiretroviral drugs efavirenz, nevirapine and zidovudine. In the present study, we provide a view of UGT2B7 haplotype structure, and quantify the genetic diversity and differentiation at both CYP2B6 and UGT2B7 genes on a worldwide scale. MATERIALS & METHODS We genotyped one intronic and three promoter SNPs, and together with three nonsynonymous SNPs, inferred UGT2B7 alleles in north American (n = 326), west African (n = 133) and Papua New Guinean (n = 142) populations. We also included genotype data for five CYP2B6 and six UGT2B7 SNPs from an additional 12 worldwide populations (n = 629) analyzed in the 1000 Genomes Project. RESULTS We observed significant differences in certain SNP and allele frequencies of CYP2B6 and UGT2B7 among worldwide populations. Diversity values were higher for UGT2B7 than for CYP2B6, although there was more diversity between populations for CYP2B6. For both genes, most of the genetic variation was observed among individuals within populations, with the Papua New Guinean population showing the highest pairwise differentiation values for CYP2B6, and the Asian and European populations showing higher pairwise differentiation values for UGT2B7. CONCLUSION These new genetic distinctions provide additional insights for investigating differences in antiretroviral pharmacokinetics and therapy outcomes among ethnically and geographically diverse populations.
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Affiliation(s)
- Jing Li
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Vincent Menard
- Pharmacogenomics Laboratory, CHUQ Research Center & Faculty of Pharmacy, Laval University, QC, Canada
| | - Rebekah L Benish
- Center for Global Health & Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Richard J Jurevic
- Department of Biological Sciences, Case Western Reserve University School of Dental Medicine, Cleveland, OH, USA
| | - Chantal Guillemette
- Pharmacogenomics Laboratory, CHUQ Research Center & Faculty of Pharmacy, Laval University, QC, Canada
| | - Mark Stoneking
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Peter A Zimmerman
- Center for Global Health & Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Rajeev K Mehlotra
- Center for Global Health & Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
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Brown C, Oki NO, Hariani G, Motsinger-Reif AA. Research Highlights. Pharmacogenomics 2012; 13:137-8. [DOI: 10.2217/pgs.11.158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Chad Brown
- Bioinformatics Research Center, Department of Statistics, North Carolina State University, Raleigh, NC 27695, USA
| | - Noffisat O Oki
- Bioinformatics Research Center, Department of Statistics, North Carolina State University, Raleigh, NC 27695, USA
| | - Gunjan Hariani
- Bioinformatics Research Center, Department of Statistics, North Carolina State University, Raleigh, NC 27695, USA
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Pavlos R, Phillips EJ. Individualization of antiretroviral therapy. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2011; 5:1-17. [PMID: 23226059 PMCID: PMC3513193 DOI: 10.2147/pgpm.s15303] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Indexed: 12/22/2022]
Abstract
Antiretroviral therapy (ART) has evolved considerably over the last three decades. From the early days of monotherapy with high toxicities and pill burdens, through to larger pill burdens and more potent combination therapies, and finally, from 2005 and beyond where we now have the choice of low pill burdens and once-daily therapies. More convenient and less toxic regimens are also becoming available, even in resource-poor settings. An understanding of the individual variation in response to ART, both efficacy and toxicity, has evolved over this time. The strong association of the major histocompatibility class I allele HLA-B*5701 and abacavir hypersensitivity, and its translation and use in routine HIV clinical practice as a predictive marker with 100% negative predictive value, has been a success story and a notable example of the challenges and triumphs in bringing pharmacogenetics to the clinic. In real clinical practice, however, it is going to be the exception rather than the rule that individual biomarkers will definitively guide patient therapy. The need for individualized approaches to ART has been further increased by the importance of non-AIDS comorbidities in HIV clinical practice. In the future, the ideal utilization of the individualized approach to ART will likely consist of a combined approach using a combination of knowledge of drug, virus, and host (pharmacogenetic and pharmacoecologic [factors in the individual’s environment that may be dynamic over time]) information to guide the truly personalized prescription. This review will focus on our knowledge of the pharmacogenetics of the efficacy and toxicity of currently available antiretroviral agents and the current and potential utility of such information and approaches in present and future HIV clinical care.
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Affiliation(s)
- Rebecca Pavlos
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Western Australia, Australia
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Presence of lamivudine or emtricitabine is associated with reduced emergence of nonnucleoside reverse transcriptase inhibitor mutations in an efavirenz-based intermittent antiretroviral treatment regimen. Antimicrob Agents Chemother 2011; 56:1655-7. [PMID: 22203586 DOI: 10.1128/aac.05452-11] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Efavirenz concentrations were measured in 21 patients during an interruption cycle of the ANRS 106 Window trial. The median efavirenz concentrations in the patients 12 h, 3 days, and 7 days after discontinuation of the drug were 1,962 ng/ml, 416 ng/ml, and 112 ng/ml, respectively. The half-life ranged from 27 to 136 h. No relationship between efavirenz exposure and detection of nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations was demonstrated. Patients who were treated by a lamivudine- or emtricitabine-based regimen had a lower risk of NNRTI mutation selection.
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Nuclear receptor-mediated induction of CYP450 by antiretrovirals: functional consequences of NR1I2 (PXR) polymorphisms and differential prevalence in whites and sub-Saharan Africans. J Acquir Immune Defic Syndr 2011; 55:536-49. [PMID: 20861742 DOI: 10.1097/qai.0b013e3181f52f0c] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Antiretroviral therapy including HIV protease inhibitors and nonnucleoside reverse transcriptase inhibitors can both inhibit and induce expression of cytochrome P450s, potentially leading to drug interactions. However, information is lacking on the impact of genetic polymorphism on this interaction. METHODS This study examines the prevalence of 33 polymorphisms in NR1I2 (pregnane X receptor [PXR]), CYP3A4, and CYP2B6 in 1013 white and sub-Saharan African patients with HIV; explores the inductive ability of 16 antiretrovirals on CYP3A4 and CYP2B6 promoter activity through nuclear receptors PXR and constitutive androstane receptor (CAR); and evaluates the influence of naturally occurring PXR genetic variants on antiretroviral activation. RESULTS Seventeen polymorphisms were present at different frequencies between the two ethnicities. Darunavir, fosamprenavir, lopinavir, nelfinavir, tipranavir, efavirenz, and abacavir increased CYP3A4 and/or CYP2B6 promoter activity, some through constitutive androstane receptor but mainly through PXR. Addition of low-dose ritonavir enhanced levels of CYP promoter activity for several protease inhibitors. Some PXR variants displayed lower fosamprenavir- and lopinavir-induced CYP3A4 promoter activity than the PXR reference sequence, whereas efavirenz and nelfinavir induction was unchanged. CONCLUSIONS The presence of NR1I2 polymorphisms can alter the induction of CYP3A4 and CYP2B6 promoter activity, potentially adding to the unpredictable nature of antiretroviral drug interactions. These polymorphisms differ in prevalence between whites and sub-Saharan Africans.
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Population pharmacokinetic/pharmacogenetic model for optimization of efavirenz therapy in Caucasian HIV-infected patients. Antimicrob Agents Chemother 2011; 55:5314-24. [PMID: 21896912 DOI: 10.1128/aac.00194-11] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Despite extensive clinical experience with efavirenz (EFV), unpredictable interindividual variabilities in efficacy and toxicity remain important limitations associated with the use of this antiretroviral. The purpose of this study was to determine the factors affecting EFV pharmacokinetics and to develop a pharmacokinetic/pharmacogenetic (PK/PG) model in a Caucasian population of HIV-infected patients. In total, 869 EFV plasma concentrations from 128 HIV-infected patients treated with EFV were quantitatively assessed using a validated high-performance liquid chromatography technique. All patients were genotyped for 90 single nucleotide polymorphisms (SNPs) in genes coding for proteins involved in the metabolism and transport of EFV, using a MassArray platform provided by Sequenom. The influence of these polymorphisms on EFV pharmacokinetics and the effects of demographic, clinical, biochemical, lifestyle, and concurrent drug covariates were evaluated. Plasma concentrations were fitted by a one-compartment model, with first-order absorption and elimination using nonlinear mixed-effect modeling (NONMEM program). The CYP2B6*6 allele, multidrug resistance-associated protein 4 (MRP4) 1497C → T, and gamma-glutamyltranspeptidase (GGT) were identified as major factors influencing the apparent EFV oral clearance (CL/F), reducing the initial interindividual variability by 54.8%, according to the model CL/F = (12.2 - 0.00279 · GGT) · 0.602(CYP2B6*6 [G/T]) · 0.354(CYP2B6*6 [T/T]) · 0.793(MRP4 1497C → T), where CYP2B6*6 [G/T], CYP2B6*6 [T/T], and MRP4 1497C → T take values of 0 or 1 to indicate the absence or presence of polymorphisms. The detailed genetic analysis conducted in this study identified two of 90 SNPs that significantly impacted CL/F, which might indicate that the remaining SNPs analyzed do not influence this PK parameter, at least in Caucasian populations with characteristics similar to those of our study population.
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Dillingham R, Leger P, Beauharnais CA, Miller E, Kashuba A, Jennings S, Dupnik K, Samie A, Eyma E, Guerrant R, Pape J, Fitzgerald D. AIDS diarrhea and antiretroviral drug concentrations: a matched-pair cohort study in Port au Prince, Haiti. Am J Trop Med Hyg 2011; 84:878-82. [PMID: 21633022 DOI: 10.4269/ajtmh.2011.10-0541] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Diarrhea in patients with acquired immunodeficiency syndrome (AIDS) may cause malabsorption of medications and failure of antiretroviral therapy (ART). We prospectively evaluated human immunodeficiency virus-1 (HIV-1)-infected patients with and without chronic diarrhea initiating ART in Haiti. We report mean plasma antiretroviral concentrations at 2 and 4 weeks. We measured plasma HIV-1 RNA levels at four points. Fifty-two HIV-1-infected patients (26 matched pairs) were enrolled. No differences in antiretroviral concentrations were detected. At week 24, 18/25 (72%) cases and 16/24 (68%) controls had undetectable plasma HIV-1 RNA levels (P = 0.69). Patients with plasma HIV-1 RNA levels > 50 copies/mL at week 24 had lower early efavirenz concentrations than patients with undetectable HIV-1 RNA (2,621 ng/mL versus 5,278 ng/mL; P = 0.02). Diarrhea at ART initiation does not influence plasma concentrations of the medications evaluated. Virologic outcome at Week 24 does correlate with efavirenz concentrations early in therapy but not with the presence of chronic diarrhea.
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Affiliation(s)
- Rebecca Dillingham
- University of Virginia School of Medicine, Center for Global Health, Charlottesville, VA 22903, USA.
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Elens L, Vandercam B, Yombi JC, Lison D, Wallemacq P, Haufroid V. Influence of host genetic factors on efavirenz plasma and intracellular pharmacokinetics in HIV-1-infected patients. Pharmacogenomics 2011; 11:1223-34. [PMID: 20860463 DOI: 10.2217/pgs.10.94] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Efavirenz (EFV) is characterized by interindividual pharmacokinetic variability causing inconsistent clinical responses. Previous studies have identified some possible genetic determinants of the variability in plasma concentrations. However, their impact on EFV intracellular pharmacokinetics remains mostly unexplored. AIMS To confirm previous observations concerning the influence of genetic polymorphisms on EFV plasma concentrations and to assess their effect on the intracellular pharmacokinetics of EFV. MATERIALS & METHODS EFV concentrations in plasma ([EFV](Cmin)) and in peripheral blood mononuclear cells ([EFV](CC)) were determined in 50 HIV-infected patients. Subjects were genotyped for 13 polymorphisms in 5 different genes (CYP2A6, CYP2B6, CYP3A5, UGT2B7 and ABCB1). Relationships between genetic status and [EFV](Cmin), [EFV](CC) or EFV accumulation in peripheral blood mononuclear cells (EFV accumulation ratio or accumulation ration [AR]) were then evaluated. RESULTS CYP2B6 allelic status was associated with differences in [EFV](Cmin) but also in [EFV](CC). Patients carrying at least one mutated allele showed significantly higher [EFV](Cmin) and [EFV](CC) than homozygous wild-type (mutated homozygous [m/m] >heterozygous [wt/m]>homozygous wild-type [wt/wt], p<0.001). ABCB1 rs3842T>C was significantly associated with higher EFV AR (p = 0.032). Finally, the ABCB1 3435C>T SNP was associated with a lower increase in CD4-cell count after EFV therapy initiation. CONCLUSION Our study corroborates previous findings indicating that knowledge of CYP2B6 genetic status should be taken into account for an EFV treatment. Our results also constitute the first demonstration of the significant influence of CYP2B6 genetic polymorphisms on [EFV](CC) and suggest that ABCB1 SNPs may also influence the clinical impact of EFV treatment.
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Affiliation(s)
- Laure Elens
- Louvain Centre for Toxicology & Applied Pharmacology, Université Catholique de Louvain, 53.02, Avenue E. Mounier, 1200 Bruxelles, Belgium.
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Rakhmanina NY, van den Anker JN. Efavirenz in the therapy of HIV infection. Expert Opin Drug Metab Toxicol 2010; 6:95-103. [PMID: 20001610 DOI: 10.1517/17425250903483207] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
IMPORTANCE OF THE FIELD The use of the first generation non-nucleoside reverse transcriptase inhibitor efavirenz (EFV) as a component of first-line antiretroviral therapy has been accepted worldwide. EFV is the only antiretroviral agent currently on the market that has been combined with emtricitabine and tenofovir disoproxil fumarate in a single tablet and administered once daily. AREAS COVERED IN THIS REVIEW This article reviews efficacy and safety data on EFV and the role of pharmacogenetics in EFV exposure. Published articles and conference presentations on EFV are reviewed. WHAT THE READER WILL GAIN CYP2B6 genetic polymorphisms influence the metabolism of EFV. The CYP2B6 G to T polymorphism at position 516 is shown to be associated with elevated plasma concentrations and an increase in neurotoxicity of EFV, while the wild-type genotype has been associated with sub-therapeutic concentrations of EFV, potentially leading to the development of viral resistance. This polymorphism is significantly higher in sub-Saharan Africans and African Americans as compared to Hispanic, European and Asian populations. TAKE HOME MESSAGE The significance of CYP2B6 polymorphism in EFV exposure indicates the need for prospective clinical studies to evaluate the utility of genotype-driven dose adjustments in populations of diverse descent.
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Affiliation(s)
- Natella Y Rakhmanina
- The George Washington University, School of Medicine and Health Sciences, Department of Pediatrics, and Special Immunology Program, Children's National Medical Center, Division of Infectious Disease, Washington, DC 20010, USA.
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