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Chala A, Kitabi EN, Ahmed JH, Tadesse BT, Chaka TE, Makonnen E, Aklillu E. Genetic and non-genetic factors influencing efavirenz population pharmacokinetics among human immunodeficiency virus-1-infected children in Ethiopia. CPT Pharmacometrics Syst Pharmacol 2023; 12:783-794. [PMID: 36840416 PMCID: PMC10272302 DOI: 10.1002/psp4.12951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 02/11/2023] [Accepted: 02/20/2023] [Indexed: 02/26/2023] Open
Abstract
Despite the potential for efavirenz (EFV) to be an effective alternative antiretroviral agent, its sources of wide inter- and intra-individual pharmacokinetic (PK) variability are not well-characterized in children. We investigated the effects of genetic and non-genetic factors, including demographic, treatment duration, baseline clinical, and biochemical characteristics, on the PKs of EFV through population-PK modeling. Antiretroviral therapy (ART) naïve HIV infected children, 3-16 years (n = 100), were enrolled in Ethiopia and received EFV-based combination ART. EFV concentrations after the first dose and at steady-state collected over a span of 1 year were modeled using population-based methods. A one-compartment model with first-order absorption kinetics described the observed EFV data adequately. The CYP2B6*6 and ABCB1c.4036A>G genotypes were identified as major factors influencing EFV clearance. The typical estimates of oral clearance, volume of distribution, and absorption rate constant for typical 22 kg children with CYP2B6 *1/*1 and ABCB1c.4036G/G genotypes were 4.3 L/h, 124 L, and 0.776/h, respectively. Clearance was reduced by 28% and 72% in CYP2B6*1/*6 and CYP2B6*6/*6 genotypes, respectively. Compared to week 1, clearance was higher from weeks 8 and 12 in CYP2B6*1/*6 and CYP2B6*1/*1 genotypes, respectively. Simulations indicated that EFV 12-h concentrations were comparable across weight bands, but more than 80% of subjects with CYP2B6*6/*6 had EFV concentrations greater than 4 μg/mL. EFV PK variability among children is partly explained by body weight, treatment duration, CYP2B6*6, and ABCB1 rs3842 genotypes. Therefore, in addition to body weight, pediatric dosing of EFV should consider pharmacogenetic variability, duration of therapy, and individual treatment outcomes.
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Affiliation(s)
- Adugna Chala
- Department of Pharmacology and Clinical Pharmacy, College of Health SciencesAddis Ababa UniversityAddis AbabaEthiopia
- Department of Global Public HealthKarolinska Institutet, Widerströmska HusetStockholmSweden
| | - Eliford Ngaimisi Kitabi
- Division of PharmacometricsOffice of Clinical Pharmacology, Food and Drugs AdministrationSilver SpringMarylandUSA
| | | | - Birkneh Tilahun Tadesse
- Department of Global Public HealthKarolinska Institutet, Widerströmska HusetStockholmSweden
- Department of Pediatrics, College of Medicine and Health SciencesHawassa UniversityHawassaEthiopia
| | - Tolossa Eticha Chaka
- Department of Pediatrics and Child HealthAdama Hospital Medical CollegeAdamaEthiopia
| | - Eyasu Makonnen
- Department of Pharmacology and Clinical Pharmacy, College of Health SciencesAddis Ababa UniversityAddis AbabaEthiopia
- Center for Innovative Drug Development and Therapeutic Trials for Africa, College of Health SciencesAddis Ababa UniversityAddis AbabaEthiopia
| | - Eleni Aklillu
- Department of Global Public HealthKarolinska Institutet, Widerströmska HusetStockholmSweden
- Department of Medicine SolnaKarolinska InstituteStockholmSweden
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Meng XM, Li ZR, Zheng XY, Liu YX, Niu WJ, Qiu XY, Lu HZ. Effect of albumin and CYP2B6 polymorphisms on exposure of efavirenz: A population pharmacokinetic analysis in Chinese HIV-infected adults. Eur J Pharm Sci 2021; 167:105986. [PMID: 34474119 DOI: 10.1016/j.ejps.2021.105986] [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: 05/20/2021] [Revised: 07/13/2021] [Accepted: 08/28/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND Efavirenz is a vital component used to treat HIV-1 infection. Nevertheless, it shows large between-subject variability, which affects both its therapeutic response and adverse effects. OBJECTIVE To investigate the impact of gene polymorphisms and non-genetic factors on the variability of efavirenz pharmacokinetics and to propose the optimal dose regimens. METHODS A total of 769 plasma samples from 376 HIV-infected Han Chinese outpatients were collected to develop a population pharmacokinetic model using NONMEM software. The impact of patient demographics, laboratory tests, concomitant medication, and genetic polymorphisms of CYP2B6 and ABCB1 on efavirenz pharmacokinetics were explored. According to the final model, the model-informed dose optimization was conducted. RESULTS The pharmacokinetics of efavirenz was characterized by a one-compartment model with first-order absorption and elimination. The typical values of the estimated apparent oral clearance, volume of distribution, and absorption rate constant in the final model were 9.44 L/h, 200 L, and 0.727 h - 1, respectively. Efavirenz clearance was significantly influenced by CYP2B6 variants, including rs2099361, rs3745274, and rs2279343, along with albumin and weight. The volume of distribution was affected by albumin and weight. Based on the CYP2B6 polymorphisms of patients, the recommended daily doses of efavirenz were 100 mg for CYP2B6 slow metabolizers, 400 or 600 mg for intermediate metabolizers, and 800 or 1000 mg for extensive metabolizers. CONCLUSIONS Polymorphisms of CYP2B6, along with albumin and weight, resulted as the predictors of efavirenz pharmacokinetic variability, which could be used in prescribing optimal efavirenz doses.
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Affiliation(s)
- Xian-Min Meng
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - Zi-Ran Li
- Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Xin-Yin Zheng
- Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Yi-Xi Liu
- Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Wan-Jie Niu
- Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Xiao-Yan Qiu
- Huashan Hospital, Fudan University, Shanghai 200040, China.
| | - Hong-Zhou Lu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China.
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Chamnanphon M, Sukprasong R, Gaedigk A, Manosuthi W, Chariyavilaskul P, Wittayalertpanya S, Koomdee N, Jantararoungtong T, Puangpetch A, Sukasem C. Influence of SULT1A1*2 Polymorphism on Plasma Efavirenz Concentration in Thai HIV-1 Patients. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2021; 14:915-926. [PMID: 34335044 PMCID: PMC8318725 DOI: 10.2147/pgpm.s306358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 06/16/2021] [Indexed: 01/11/2023]
Abstract
Purpose Plasma efavirenz (EFV) concentrations within therapeutic levels are essential to successfully treat patients suffering from human immunodeficiency virus (HIV) type 1. In addition to the drug-metabolizing enzyme CYP2B6, other phase II drug-metabolizing enzymes and transporters may have an important role in the pharmacokinetics of EFV. Thus, the influence of phase II drug-metabolizing enzymes and drug transporters on plasma EFV levels was investigated in Thai HIV patients receiving EFV. Patients and Methods Genotyping was performed by TaqMan® real-time PCR in 149 HIV-infected Thai adults, and plasma efavirenz concentration was measured by a validated high-performance liquid chromatography in 12 hours after dosing steady-state plasma samples at week 12 and 24. Results Patients with three or more copies of SULT1A1 had significantly lower median plasma EFV concentrations than those carrying two copies at week 12 (p=0.046) and SULT1A1*2 (c.638G>A) carriers had significantly lower median plasma EFV concentrations compared to those not carrying the variant at week 24 (p=0.048). However, no significant association was found after adjusting for CYP2B6 genotype. Conclusion Genetic variation in a combination of SULT1A1*2 and SULT1A1 copy number may contribute to variability in EFV metabolism and thereby may impact drug response. The influence of a combination between the SULT1A1 and CYP2B6 genotype on EFV pharmacokinetics should be further investigated in a larger study population.
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Affiliation(s)
- Monpat Chamnanphon
- Department of Pathology, Faculty of Medicine, Srinakharinwirot University, Nakornnayok, Thailand.,Clinical Pharmacokinetics and Pharmacogenomics Research Unit, Department of Pharmacology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Rattanaporn Sukprasong
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.,Laboratory for Pharmacogenomics, Somdech Phra Debaratana Medical Center (SDMC), Ramathibodi Hospital, Bangkok, Thailand
| | - Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology & Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, MO, USA.,School of Medicine, University of Missouri-Kansas City, Kansas City, MO, USA
| | - Weerawat Manosuthi
- Bamrasnaradura Infectious Diseases Institute, Ministry of Public Health, Nonthaburi, Thailand
| | - Pajaree Chariyavilaskul
- Clinical Pharmacokinetics and Pharmacogenomics Research Unit, Department of Pharmacology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Supeecha Wittayalertpanya
- Clinical Pharmacokinetics and Pharmacogenomics Research Unit, Department of Pharmacology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Napatrupron Koomdee
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.,Laboratory for Pharmacogenomics, Somdech Phra Debaratana Medical Center (SDMC), Ramathibodi Hospital, Bangkok, Thailand
| | - Thawinee Jantararoungtong
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.,Laboratory for Pharmacogenomics, Somdech Phra Debaratana Medical Center (SDMC), Ramathibodi Hospital, Bangkok, Thailand
| | - Apichaya Puangpetch
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.,Laboratory for Pharmacogenomics, Somdech Phra Debaratana Medical Center (SDMC), Ramathibodi Hospital, Bangkok, Thailand
| | - Chonlaphat Sukasem
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.,Laboratory for Pharmacogenomics, Somdech Phra Debaratana Medical Center (SDMC), Ramathibodi Hospital, Bangkok, Thailand
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Chaivichacharn P, Avihingsanon A, Manosuthi W, Ubolyam S, Tongkobpetch S, Shotelersuk V, Punyawudho B. Dosage Optimization of Efavirenz Based on a Population Pharmacokinetic-Pharmacogenetic Model of HIV-infected Patients in Thailand. Clin Ther 2020; 42:1234-1245. [PMID: 32451120 DOI: 10.1016/j.clinthera.2020.04.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 04/21/2020] [Accepted: 04/22/2020] [Indexed: 01/11/2023]
Abstract
PURPOSE Efavirenz exhibits high interindividual variability in plasma concentrations, leading to unpredictable efficacy and toxicity. Polymorphism of CYP2B6 516G > T has been found to predominantly contribute to efavirenz variability. However, dosage recommendations incorporating CYP2B6 516G > T polymorphism have not been investigated in the Thai population. This study aimed to develop a population model of the pharmacokinetic properties of efavirenz, and to investigate the impact of patients' characteristics and CYP2B6 516G > T polymorphism on the pharmacokinetic properties of efavirenz. Model-based simulations were performed to provide genotype-based dosage optimization in a Thai population. METHODS Plasma efavirenz concentrations measured at 12 h post-dose in 360 Thai HIV-infected patients with and without tuberculosis were analyzed by the nonlinear mixed-effects modeling approach. A 1-compartment model with first-order absorption and elimination was used for describing the pharmacokinetic properties of efavirenz. FINDINGS The allele frequency of CYP2B6 516G > T was 34.17%. The efavirenz oral clearance were 11.9, 8.0, and 2.8 L/h in patients weighing 57 kg and having the CYP2B6 516 GG, 516 GT, and 516 TT genotypes, respectively. The use of rifampicin increased efavirenz oral clearance by 28%. The results from the simulations suggest that efavirenz dosages of 400, 300, and 100 mg once daily in Thai HIV mono-infected patients, and 800, 600, and 200 mg once daily in HIV/tuberculosis co-infected patients carrying CYP2B6 516 GG, 516 GT, and 516 TT, respectively. IMPLICATION The results from this study provide a rationale for efavirenz dose adjustment based on CYP2B6 516G > T polymorphism in Thai HIV-infected patients, which could help to improve treatment outcomes in this population. ClinicalTrials.gov identifier: NCT01138267.
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Affiliation(s)
- Piyawat Chaivichacharn
- Department of Pharmaceutical Care, Faculty of Pharmacy, Chiang Mai University, Chiang Mai, Thailand
| | - Anchalee Avihingsanon
- HIV-NAT, Thai Red Cross AIDS Research Centre, Bangkok, Thailand; Tuberculosis Research Unit, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Weerawat Manosuthi
- Bamrasnaradura Infectious Diseases Institute, Ministry of Public Health, Mueang Nonthaburi, Thailand
| | | | - Siraprapa Tongkobpetch
- Center of Excellence for Medical Genomics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Center of Excellence for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
| | - Vorasuk Shotelersuk
- Center of Excellence for Medical Genomics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Center of Excellence for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
| | - Baralee Punyawudho
- Department of Pharmaceutical Care, Faculty of Pharmacy, Chiang Mai University, Chiang Mai, Thailand.
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Chetty M, Danckwerts MP, Julsing A. Prediction of the exposure to a 400-mg daily dose of efavirenz in pregnancy: is this dose adequate in extensive metabolisers of CYP2B6? Eur J Clin Pharmacol 2020; 76:1143-1150. [DOI: 10.1007/s00228-020-02890-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 05/01/2020] [Indexed: 12/26/2022]
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Pharmacogenomics in Papua New Guineans: unique profiles and implications for enhancing drug efficacy while improving drug safety. Pharmacogenet Genomics 2019; 28:153-164. [PMID: 29768302 DOI: 10.1097/fpc.0000000000000335] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Papua New Guinea (PNG) can be roughly divided into highland, coastal and island peoples with significant mitochondrial DNA differentiation reflecting early and recent distinct migrations from Africa and East Asia, respectively. Infectious diseases such as tuberculosis, malaria and HIV severely impact on the health of its peoples for which drug therapy is the major treatment and pharmacogenetics has clinical relevance for many of these drugs. Although there is generally little information about known single nucleotide polymorphisms in the population, in some instances, their frequencies have been shown to be higher than anywhere worldwide. For example, CYP2B6*6 is over 50%, and CYP2C19*2 and *3 are over 40 and 25%, respectively. Conversely, CYP2A6*9, 2B6*2, *3, *4 and *18, and 2C8*3 appear to be much lower than in Whites. CYP2D6 known variants are unclear, and for phase II enzymes, only UGT2B7 and UGT1A9 data are available, with variant frequencies either slightly lower than or similar to Whites. Although almost all PNG people tested are rapid acetylators, but which variant(s) define this phenotype is not known. For HLA-B*13:01, HLA-B*35:05 and HLA-C*04:01, the frequencies show some regioselectivity, but the clinical implications with respect to adverse drug reactions are not known. There are minimal phenotype data for the CYPs and nothing is known about drug transporter or receptor genetics. Determination of genetic variants that are rare in Whites or Asians but common in PNG people is a topic of both scientific and clinical importance, and further research needs to be carried out. Optimizing the safety and efficacy of infectious disease drug therapy through pharmacogenetic studies that have translation potential is a priority.
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Singh H, Lata S, Dhole TN, Gangakhedkar RR. Occurrence of CYP2B6 516G>T polymorphism in patients with ARV-associated hepatotoxicity. Mol Genet Genomic Med 2019; 7:e00598. [PMID: 30864294 PMCID: PMC6465650 DOI: 10.1002/mgg3.598] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 11/14/2018] [Accepted: 01/10/2019] [Indexed: 01/11/2023] Open
Abstract
Background Hepatic enzyme cytochrome P450 2B6 (CYP2B6) plays a role in the metabolism of efavirenz drugs. CYP2B6 516G>T variation showed an implication for HIV treatment. Methods CYP2B6 516G>T polymorphism was genotyped in a total 165 HIV patients that include 34 with and 131 without hepatotoxicity and 155 healthy individuals by the PCR‐RFLP. Results In patients with hepatotoxicity, the prevalence of CYP2B6 516TT genotype was higher as compared to healthy individuals (35.3% vs. 30.5%, OR = 1.74). Patients with hepatotoxicity using tobacco had a higher prevalence of genotypes CYP2B6 516GT, 516TT, 516GT+TT as compared to healthy individuals (28.57% vs. 25.93%; 57.14% vs. 29.63%; 85.71% vs. 55.56%). Likewise, hepatotoxicity in patients consuming alcohol showed higher distributions of CYP2B6 516GT, 516TT, 516GT+TT genotypes (57% vs. 25.93%; 42.86% vs. 33.33%; 71.43% vs. 59.26%). Nevirapine users with hepatotoxicity overrepresented genotypes CYP2B6 TT and 516GT+TT as compared to efavirenz users (47.83% vs. 45.45%, OR = 6.88, 65.22% vs. 54.55%, OR = 1.56). Similarly, in nevirapine +alcohol users with hepatotoxicity, the frequency of CYP2B6 516GT, 516GT+TT genotypes was higher than with nevirapine +alcohol nonusers (40.0% vs. 11.11%, OR = 8.00, 80.0% vs. 27.78%, OR = 4.00). In HIV patients, nevirapine users had higher frequency of CYP2B6 516GT, 516GT+TT genotypes as compared to efavirenz users (42.02% vs. 25.00%, OR = 2.53; 72.27% vs. 58.33%, OR = 1.86). Likewise, in HIV patients, genotypes CYP2B6 516GT, 516GT+TT were predominant with nevirapine +alcohol users as compared to nevirapine +alcohol nonusers (57.89% vs. 34.57%, OR = 2.46; 78.95% vs. 69.14%, OR = 1.67). In multivariate logistic regression, taking nevirapine had a protection for severity of ARV‐associated hepatotoxicity (OR = 0.23, p = 0.005). Conclusions No significant association was detected between CYP2B6 516G>T polymorphism and susceptibility to ARV‐associated hepatotoxicity.
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Affiliation(s)
- HariOm Singh
- Department of Molecular Biology, National AIDS Research Institute, Pune, India
| | - Sonam Lata
- Department of Molecular Biology, National AIDS Research Institute, Pune, India
| | - T N Dhole
- Department of Microbiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
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Long-term efavirenz pharmacokinetics is comparable between Tanzanian HIV and HIV/Tuberculosis patients with the same CYP2B6*6 genotype. Sci Rep 2018; 8:16316. [PMID: 30397233 PMCID: PMC6218524 DOI: 10.1038/s41598-018-34674-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 10/23/2018] [Indexed: 01/11/2023] Open
Abstract
The impact of anti-tuberculosis co-treatment on efavirenz (EFV) exposure is still uncertain as contradictory reports exist, and the relevance of CYP2B6*6 genetic polymorphism on efavirenz clearance while on-and-off anti-tuberculosis co-treatment is not well investigated. We investigated the determinants of long-term efavirenz pharmacokinetics by enrolling HIV (n = 20) and HIV/Tuberculosis (n = 36) subjects undergoing efavirenz and efavirenz/rifampicin co-treatment respectively. Pharmacokinetic samplings were done 16 weeks after initiation of efavirenz-based anti-retroviral therapy and eight weeks after completion of rifampicin-based anti-tuberculosis treatment. Population pharmacokinetic modeling was used to characterize variabilities and covariates of efavirenz pharmacokinetic parameters. CYP2B6*6 genetic polymorphism but not rifampicin co-treatment was the statistically significant covariate. The estimated typical efavirenz clearance in the HIV only subjects with the CYP2B6*1/*1 genotype was 23.6 L/h/70 kg, while it was 38% and 69% lower in subjects with the CYP2B6*1/*6 and *6/*6 genotypes, respectively. Among subjects with the same CYP2B6 genotypes, efavirenz clearances were comparable between HIV and HIV/Tuberculosis subjects. Typical efavirenz clearances before and after completion of anti-tuberculosis therapy were comparable. In conclusion, after 16 weeks of treatment, efavirenz clearance is comparable between HIV and HIV/Tuberculosis patients with the same CYP2B6 genotype. CYP2B6 genotyping but not anti-tuberculosis co-treatment should guide efavirenz dosing to optimize treatment outcomes.
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Dalwadi DA, Ozuna L, Harvey BH, Viljoen M, Schetz JA. Adverse Neuropsychiatric Events and Recreational Use of Efavirenz and Other HIV-1 Antiretroviral Drugs. Pharmacol Rev 2018; 70:684-711. [DOI: 10.1124/pr.117.013706] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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Duarte H, Cruz JP, Aniceto N, Ribeiro AC, Fernandes A, Paixão P, Antunes F, Morais J. Population Approach to Efavirenz Therapy. J Pharm Sci 2017. [PMID: 28622951 DOI: 10.1016/j.xphs.2017.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Efavirenz (EFV) is a nonnucleoside reverse transcriptase inhibitor commonly used as first-line therapy in the treatment of human immunodeficiency virus (HIV), with a narrow therapeutic range and a high between-subject variability which can lead to central nervous system toxicity or therapeutic failure. To characterize the sources of variability and better predict EFV steady-state plasma concentrations, a population pharmacokinetic model was developed from 96 HIV-positive individuals, using a nonlinear mixed-effect method with Monolix® software. A one-compartment with first-order absorption and elimination model adequately described the data. To explain between-subject variability, demographic characteristics, biochemical parameters, hepatitis C virus-HIV coinfection, and genetic polymorphisms were tested. A combination of the single-nucleotide polymorphisms rs2279343 and rs3745274, both in the CYP2B6 gene, were the only covariates influencing clearance, included in the final model. Oral clearance was estimated to be 19.6 L/h, 14.15 L/h, and 6.08 L/h for wild-type, heterozygous mutated and homozygous mutated individuals, respectively. These results are in accordance with the current knowledge of EFV metabolism and also suggest that in homozygous mutated individuals, a dose adjustment is necessary. Hepatitis C virus-HIV coinfection does not seem to be a predictive indicator of EFV pharmacokinetic disposition.
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Affiliation(s)
- Hélder Duarte
- Departamento de Ciências Farmacológicas, Faculdade de Farmácia da Universidade de Lisboa, Lisboa, Portugal.
| | - João Paulo Cruz
- Departamento de Ciências Farmacológicas, Faculdade de Farmácia da Universidade de Lisboa, Lisboa, Portugal; Laboratório de Diagnóstico de Doenças Infecciosas, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Natália Aniceto
- Departamento de Ciências Farmacológicas, Faculdade de Farmácia da Universidade de Lisboa, Lisboa, Portugal; Laboratório de Diagnóstico de Doenças Infecciosas, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Ana Clara Ribeiro
- Centro de investigação interdisciplinar Egas Moniz, Instituto Superior de Ciências da Saúde Egas Moniz, Caparica, Portugal
| | - Ana Fernandes
- Laboratório de Diagnóstico de Doenças Infecciosas, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal; Centro de investigação interdisciplinar Egas Moniz, Instituto Superior de Ciências da Saúde Egas Moniz, Caparica, Portugal
| | - Paulo Paixão
- Departamento de Ciências Farmacológicas, Faculdade de Farmácia da Universidade de Lisboa, Lisboa, Portugal
| | - Francisco Antunes
- Instituto de Saúde Ambiental, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - José Morais
- Departamento de Ciências Farmacológicas, Faculdade de Farmácia da Universidade de Lisboa, Lisboa, Portugal
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Population Pharmacokinetic Modeling To Estimate the Contributions of Genetic and Nongenetic Factors to Efavirenz Disposition. Antimicrob Agents Chemother 2016; 61:AAC.01813-16. [PMID: 27799204 DOI: 10.1128/aac.01813-16] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 10/22/2016] [Indexed: 01/03/2023] Open
Abstract
Efavirenz pharmacokinetics is characterized by large between-subject variability, which determines both therapeutic response and adverse effects. Some of the variability in efavirenz pharmacokinetics has been attributed to genetic variability in cytochrome P450 genes that alter efavirenz metabolism, such as CYP2B6 and CYP2A6 While the effects of additional patient factors have been studied, such as sex, weight, and body mass index, the extent to which they contribute to variability in efavirenz exposure is inconsistently reported. The aim of this analysis was to develop a pharmacometric model to quantify the contribution of genetic and nongenetic factors to efavirenz pharmacokinetics. A population-based pharmacokinetic model was developed using 1,132 plasma efavirenz concentrations obtained from 73 HIV-seronegative volunteers administered a single oral dose of 600 mg efavirenz. A two-compartment structural model with absorption occurring by zero- and first-order processes described the data. Allometric scaling adequately described the relationship between fat-free mass and apparent oral clearance, as well as fat mass and apparent peripheral volume of distribution. Inclusion of fat-free mass and fat mass in the model mechanistically accounted for correlation between these disposition parameters and sex, weight, and body mass index. Apparent oral clearance of efavirenz was reduced by 25% and 51% in subjects predicted to have intermediate and slow CYP2B6 metabolizer status, respectively. The final pharmacokinetic model accounting for fat-free mass, fat mass, and CYP2B6 metabolizer status was consistent with known mechanisms of efavirenz disposition, efavirenz physiochemical properties, and pharmacokinetic theory. (This study has been registered at ClinicalTrials.gov under identifier NCT00668395.).
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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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13
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Nightingale S, Chau TTH, Fisher M, Nelson M, Winston A, Else L, Carr DF, Taylor S, Ustianowski A, Back D, Pirmohamed M, Solomon T, Farrar J, Törok ME, Khoo S. Efavirenz and Metabolites in Cerebrospinal Fluid: Relationship with CYP2B6 c.516G→T Genotype and Perturbed Blood-Brain Barrier Due to Tuberculous Meningitis. Antimicrob Agents Chemother 2016; 60:4511-8. [PMID: 27161633 PMCID: PMC4958147 DOI: 10.1128/aac.00280-16] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Accepted: 05/04/2016] [Indexed: 01/11/2023] Open
Abstract
Efavirenz (EFZ) has been associated with neuropsychiatric side effects. Recently, the 8-hydroxy-EFZ (8OH-EFZ) metabolite has been shown to be a potent neurotoxin in vitro, inducing neuronal damage at concentrations of 3.3 ng/ml. EFZ induced similar neuronal damage at concentrations of 31.6 ng/ml. We investigated the effect of genotype and blood-brain barrier integrity on EFZ metabolite concentrations in cerebrospinal fluid (CSF). We measured CSF drug concentrations in subjects from two separate study populations: 47 subjects with tuberculous meningitis (TBM) coinfection in Vietnam receiving 800 mg EFZ with standard antituberculous treatment and 25 subjects from the PARTITION study in the United Kingdom without central nervous system infection receiving 600 mg EFZ. EFZ and metabolite concentrations in CSF and plasma were measured and compared with estimates of effectiveness and neurotoxicity from available published in vitro and in vivo data. The effect of the CYP2B6 c.516G→T genotype (GG genotype, fast EFV metabolizer status; GT genotype, intermediate EFV metabolizer status; TT genotype, slow EFV metabolizer status) was examined. The mean CSF concentrations of EFZ and 8OH-EFZ in the TBM group were 60.3 and 39.3 ng/ml, respectively, and those in the no-TBM group were 15.0 and 5.9 ng/ml, respectively. Plasma EFZ and 8OH-EFZ concentrations were similar between the two groups. CSF EFZ concentrations were above the in vitro toxic concentration in 76% of samples (GG genotype, 61%; GT genotype, 90%; TT genotype, 100%) in the TBM group and 13% of samples (GG genotype, 0%; GT genotype, 18%; TT genotype, 50%) in the no-TBM group. CSF 8OH-EFZ concentrations were above the in vitro toxic concentration in 98% of the TBM group and 87% of the no-TBM group; levels were independent of genotype but correlated with the CSF/plasma albumin ratio. Potentially neurotoxic concentrations of 8OH-EFZ are frequently observed in CSF independently of the CYP2B6 genotype, particularly in those with impaired blood-brain barrier integrity.
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Affiliation(s)
- Sam Nightingale
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, United Kingdom Royal Liverpool and Broadgreen University Hospitals NHS Trust, Liverpool, United Kingdom
| | - Tran Thi Hong Chau
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Martin Fisher
- Brighton and Sussex University Hospitals NHS Trust, Brighton, United Kingdom
| | - Mark Nelson
- St. Stephen's AIDS Research Trust and Chelsea and Westminster Hospital NHS Foundation Trust, London, United Kingdom
| | - Alan Winston
- St. Mary's Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Laura Else
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, United Kingdom
| | - Daniel F Carr
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, United Kingdom
| | - Steven Taylor
- Birmingham Heartlands Hospital, Heart of England NHS Foundation Trust, Birmingham, United Kingdom
| | - Andrew Ustianowski
- North Manchester General Hospital, Pennine Acute Hospitals NHS Trust, Manchester, United Kingdom
| | - David Back
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, United Kingdom
| | - Munir Pirmohamed
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, United Kingdom
| | - Tom Solomon
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom Walton Centre for Neurology and Neurosurgery, Liverpool, United Kingdom
| | - Jeremy Farrar
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam Centre for Tropical Medicine, University of Oxford, Oxford, United Kingdom
| | - M Estée Törok
- University of Cambridge, Department of Medicine, Cambridge, United Kingdom Cambridge University Hospitals, NHS Foundation Trust, Cambridge, United Kingdom Public Health England, Clinical Microbiology and Public Health Laboratory, Cambridge, United Kingdom
| | - Saye Khoo
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, United Kingdom Royal Liverpool and Broadgreen University Hospitals NHS Trust, Liverpool, United Kingdom
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14
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Gene-gene interactions between DRD3, MRP4 and CYP2B6 polymorphisms and its influence on the pharmacokinetic parameters of efavirenz in HIV infected patients. Drug Metab Pharmacokinet 2016; 31:349-355. [PMID: 27665700 DOI: 10.1016/j.dmpk.2016.06.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 05/23/2016] [Accepted: 06/19/2016] [Indexed: 01/11/2023]
Abstract
Genetic factors have a significant impact on the PK variability of EFV, much higher than other non-genetic factors, such as demography. In this work we have performed a comprehensive PG analysis of genes encoding the major metabolizing enzymes and transporters of EFV, establishing a clear relationship between the PK parameters and genetic factors, which explain 50% of the variability in EFV PK parameters. The most relevant associations for metabolizing enzymes were found in CYP2B6 (rs3745274), in agreement with previous studies. The influence of transporters on the kinetics of EFV was also proved with significant correlations between the PK parameters of EFV and MRP4 (rs1751034, rs2274407). Analysis of gene-gene interactions with CYP2B6 was particularly useful to reinforce the role of MRP4 and to reveal unknown associations, such as that of DRD3. However, the role of DRD3 cannot be a direct effect but an indirect one due to physical proximity of NAT and the DRD3 locus in the genome.
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15
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Bienczak A, Cook A, Wiesner L, Olagunju A, Mulenga V, Kityo C, Kekitiinwa A, Owen A, Walker AS, Gibb DM, McIlleron H, Burger D, Denti P. The impact of genetic polymorphisms on the pharmacokinetics of efavirenz in African children. Br J Clin Pharmacol 2016; 82:185-98. [PMID: 26991336 PMCID: PMC4917805 DOI: 10.1111/bcp.12934] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 03/07/2016] [Accepted: 03/10/2016] [Indexed: 01/11/2023] Open
Abstract
Aims Using a model‐based approach, the efavirenz steady‐state pharmacokinetics in African children is characterized, quantifying demographic and genotypic effects on the drug's disposition. Simulations are also conducted allowing prediction of optimized doses of efavirenz in this population. Methods We modelled the steady‐state population pharmacokinetics of efavirenz in Ugandan and Zambian children using nonlinear mixed‐effects modelling. Individual mid‐dose efavirenz concentrations were derived and simulations explored genotype‐based dose optimization strategies. Results A two‐compartment model with absorption through transit compartments well described 2086 concentration‐time points in 169 children. The combined effect of single nucleotide polymorphisms (SNPs) 516G>T and 983T>C explained 44.5% and 14.7% of the variability in efavirenz clearance and bioavailability, respectively. The detected frequencies of composite CYP2B6 genotype were 0.33 for 516GG|983TT, 0.35 for 516GT|983TT, 0.06 for 516GG|983TC, 0.18 for 516TT|983TT, 0.07 516GT|983TC and 0.01 for 516GG|983CC. The corresponding estimated clearance rates were 6.94, 4.90, 3.93, 1.92, 1.36, and 0.74 l h−1 for a 15.4 kg child and median (95% CI) observed mid‐dose concentrations 1.55 (0.51–2.94), 2.20 (0.97–4.40), 2.03 (1.19–4.53), 7.55 (2.40–14.74), 7.79 (3.66–24.59) and 18.22 (11.84–22.76) mg l−1, respectively. Simulations showed that wild‐type individuals had exposures at the bottom of therapeutic range, while slower metabolizers were overexposed. Conclusions Dosage guidelines for African children should take into consideration the combined effect of SNPs CYP2B6 516G>T and 983T>C.
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Affiliation(s)
- Andrzej Bienczak
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Adrian Cook
- MRC Clinical Trials Unit at University College London, London, UK
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Adeniyi Olagunju
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK
| | - Veronica Mulenga
- University Teaching Hospital, Department of Paediatrics and Child Health, Lusaka, Zambia
| | - Cissy Kityo
- Joint Clinical Research Centre, Kampala, Uganda
| | - Addy Kekitiinwa
- Baylor College of Medicine Bristol Myers Squibb Children's Clinical Centre of Excellence, Kampala, Uganda / Gulu Regional Centre of Excellence, Gulu, Uganda
| | - Andrew Owen
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK
| | - A Sarah Walker
- MRC Clinical Trials Unit at University College London, London, UK
| | - Diana M Gibb
- MRC Clinical Trials Unit at University College London, London, UK
| | - Helen McIlleron
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - David Burger
- Department of Pharmacy, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
| | - Paolo Denti
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
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16
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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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17
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Swart M, Evans J, Skelton M, Castel S, Wiesner L, Smith PJ, Dandara C. An Expanded Analysis of Pharmacogenetics Determinants of Efavirenz Response that Includes 3'-UTR Single Nucleotide Polymorphisms among Black South African HIV/AIDS Patients. Front Genet 2016; 6:356. [PMID: 26779253 PMCID: PMC4703773 DOI: 10.3389/fgene.2015.00356] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 12/10/2015] [Indexed: 01/11/2023] Open
Abstract
Introduction: Efavirenz (EFV) is a non-nucleoside reverse transcriptase inhibitor prescribed as part of first-line highly active antiretroviral therapy (HAART) in South Africa. Despite administration of fixed doses of EFV, inter-individual variability in plasma concentrations has been reported. Poor treatment outcomes such as development of adverse drug reactions or treatment failure have been linked to EFV plasma concentrations outside the therapeutic range (1–4 μg/mL) in some studies. The drug metabolizing enzyme (DME), CYP2B6, is primarily responsible for EFV metabolism with minor contributions by CYP1A2, CYP2A6, CYP3A4, CYP3A5, and UGT2B7. DME coding genes are also regulated by microRNAs through targeting the 3′-untranslated region. Expanded analysis of 30 single nucleotide polymorphisms (SNPs), including those in the 3′-UTR, was performed to identify pharmacogenetics determinants of EFV plasma concentrations in addition to CYP2B6 c.516G>T and c.983T>C SNPs. Methods: SNPs in CYP1A2, CYP2B6, UGT2B7, and NR1I2 (PXR) were selected for genotyping among 222 Bantu-speaking South African HIV-infected patients receiving EFV-containing HAART. This study is a continuation of earlier pharmacogenetics studies emphasizing the role of genetic variation in the 3′-UTR of genes which products are either pharmacokinetic or pharmacodynamic targets of EFV. Results: Despite evaluating thirty SNPs, CYP2B6 c.516G>T and c.983T>C SNPs remain the most prominent predictors of EFV plasma concentration. Conclusion: We have shown that CYP2B6 c.516G>T and c.983T>C SNPs are the most important predictors of EFV plasma concentration after taking into account all other SNPs, including genetic variation in the 3′-UTR, and variables affecting EFV metabolism.
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Affiliation(s)
- Marelize Swart
- 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
| | - Jonathan Evans
- 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
| | - Michelle Skelton
- 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
| | - Sandra Castel
- Division of Clinical Pharmacology, Faculty of Health Sciences, University of Cape Town Cape Town, South Africa
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Faculty of Health Sciences, University of Cape Town Cape Town, South Africa
| | - Peter J Smith
- Division of Clinical Pharmacology, Faculty of Health Sciences, University of Cape Town Cape Town, South Africa
| | - Collet Dandara
- 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
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18
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Russo G, Paganotti GM, Soeria-Atmadja S, Haverkamp M, Ramogola-Masire D, Vullo V, Gustafsson LL. Pharmacogenetics of non-nucleoside reverse transcriptase inhibitors (NNRTIs) in resource-limited settings: Influence on antiretroviral therapy response and concomitant anti-tubercular, antimalarial and contraceptive treatments. INFECTION GENETICS AND EVOLUTION 2015; 37:192-207. [PMID: 26602158 DOI: 10.1016/j.meegid.2015.11.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 11/13/2015] [Accepted: 11/16/2015] [Indexed: 01/11/2023]
Abstract
The burden of human immunodeficiency virus (HIV) is mainly concentrated to resources-limited countries where the response to available antiretroviral therapy is often limited by the occurrence of toxicity or by the emergence of HIV drug resistance. Efavirenz and nevirapine are the antiretroviral drugs most prescribed in resources-limited countries as part of antiretroviral combination therapy. Their metabolism and conjugation are largely influenced by enzymatic genetic polymorphisms. The genetic variability of their metabolism could be associated to different metabolic phenotypes causing reduced patients' adherence because of toxicity or drug-drug interactions with concomitant therapies. The purpose of this review is to summarize published evidence on pharmacogenetic and pharmacokinetic aspects related to efavirenz and nevirapine, the influence of concomitant anti-tubercular, anti-malarial or contraceptive treatments, and the impact of human genetic variation and drug-drug interaction on the virologic and immunologic response to antiretroviral therapy in resources-limited countries.
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Affiliation(s)
- Gianluca Russo
- Department of Public Health and Infectious Diseases, University "La Sapienza", P.le Aldo Moro 5, 00185 Rome, Italy
| | - Giacomo Maria Paganotti
- Botswana-University of Pennsylvania Partnership, P.O. Box AC 157 ACH, Gaborone, Botswana; Medical Education Partnership Laboratory, c/o Faculty of Medicine, University of Botswana, Pvt Bag 00713, Gaborone, Botswana.
| | - Sandra Soeria-Atmadja
- Division of Pediatrics, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Karolinska University Hospital, B57, SE-141 86, Stockholm, Sweden
| | - Miriam Haverkamp
- Botswana-University of Pennsylvania Partnership, P.O. Box AC 157 ACH, Gaborone, Botswana
| | - Doreen Ramogola-Masire
- Botswana-University of Pennsylvania Partnership, P.O. Box AC 157 ACH, Gaborone, Botswana
| | - Vincenzo Vullo
- Department of Public Health and Infectious Diseases, University "La Sapienza", P.le Aldo Moro 5, 00185 Rome, Italy
| | - Lars Lennart Gustafsson
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, SE-141 86, Stockholm, Sweden
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19
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Apostolova N, Funes HA, Blas-Garcia A, Galindo MJ, Alvarez A, Esplugues JV. Efavirenz and the CNS: what we already know and questions that need to be answered. J Antimicrob Chemother 2015. [PMID: 26203180 DOI: 10.1093/jac/dkv183] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The NNRTI efavirenz has long been one of the most frequently employed antiretroviral drugs in the multidrug regimens used to treat HIV infection, in accordance with its well-demonstrated antiretroviral efficacy and favourable pharmacokinetics. However, growing concern about its adverse effects has sometimes led to efavirenz being replaced by other drugs in the initial treatment selection or to switching of therapy to efavirenz-free regimens in experienced patients. Neurological and neuropsychiatric reactions are the manifestations most frequently experienced by efavirenz-treated patients and range from transitory effects, such as nightmares, dizziness, insomnia, nervousness and lack of concentration, to more severe symptoms including depression, suicidal ideation or even psychosis. In addition, efavirenz has recently been associated with mild/moderate neurocognitive impairment, which is of specific relevance given that half of the patients receiving ART eventually suffer some form of HIV-associated neurocognitive disorder. The mechanisms responsible for efavirenz-induced neurotoxicity are unclear, although growing evidence points to disturbances in brain mitochondrial function and bioenergetics. This review offers a comprehensive overview of the current evidence on the interaction that efavirenz displays with the CNS, including the penetration and concentration of the drug in the brain. We discuss the prevalence, types and specificities of its side effects and recently uncovered cellular mechanisms that may be involved in their development.
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Affiliation(s)
- Nadezda Apostolova
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain Facultad de Ciencias de la Salud, Universitat Jaume I, Castellón de la Plana, Spain CIBERehd (Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas), Valencia, Spain
| | - Haryes A Funes
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain
| | - Ana Blas-Garcia
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain CIBERehd (Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas), Valencia, Spain FISABIO-Hospital Universitario Dr Peset, Valencia, Spain
| | - Maria J Galindo
- Unidad de Enfermedades Infecciosas-Medicina Interna, Hospital Clínico Universitario de Valencia, Valencia, Spain
| | - Angeles Alvarez
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain CIBERehd (Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas), Valencia, Spain
| | - Juan V Esplugues
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain CIBERehd (Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas), Valencia, Spain FISABIO-Hospital Universitario Dr Peset, Valencia, Spain
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20
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Dhoro M, Zvada S, Ngara B, Nhachi C, Kadzirange G, Chonzi P, Masimirembwa C. CYP2B6*6, CYP2B6*18, Body weight and sex are predictors of efavirenz pharmacokinetics and treatment response: population pharmacokinetic modeling in an HIV/AIDS and TB cohort in Zimbabwe. BMC Pharmacol Toxicol 2015; 16:4. [PMID: 25889207 PMCID: PMC4405819 DOI: 10.1186/s40360-015-0004-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 03/05/2015] [Indexed: 01/11/2023] Open
Abstract
Background Efavirenz (EFV) therapeutic response and toxicity are associated with high inter-individual variability attributed to variation in its pharmacokinetics. Plasma concentrations below 1 μg/ml may result in virologic failure and above 4 μg/ml, may result in central nervous system adverse effects. This study used population pharmacokinetics modeling to explore the influence of demographic and pharmacogenetic factors including efavirenz-rifampicin interaction on EFV pharmacokinetics, towards safer dosing of EFV. Methods Patients receiving an EFV-based regimen for their antiretroviral therapy and a rifampicin-containing anti-TB regimen were recruited. EFV plasma concentrations were measured by HPLC and genomic DNA genotyped for variants in the CYP2B6, CYP2A6 and ABCB1 genes. All patients were evaluated for central nervous system adverse effects characterised as sleep disorders, hallucinations and headaches using the WHO ADR grading system. A pharmacokinetic model was built in a forward and reverse procedure using nonlinear mixed effect modeling in NONMEM VI followed by model-based simulations for optimal doses. Results CYP2B6*6 and *18 variant alleles, weight and sex were the most significant covariates explaining 55% of inter-individual variability in EFV clearance. Patients with the CYP2B6*6TT genotype had a 63% decrease in EFV clearance despite their CYP2B6*18 genotypes with females having 22% higher clearance compared to males. There was a 21% increase in clearance for every 10 kg increase in weight. The effect of TB/HIV co-treatment versus HIV treatment only was not statistically significant. No clinically relevant association between CYP2B6 genotypes and CNS adverse effects was seen, but patients with CNS adverse effects had a 27% lower clearance compared to those without. Model- based simulations indicated that all carriers of CYP2B6*6 TT genotype would be recommended a dose reduction to 200 mg/day, while the majority of extensive metabolisers may be given 400 mg/day and still maintain therapeutic levels. Conclusion This study showed that screening for CYP2B6 functional variants has a high predictability for efavirenz plasma levels and could be used in prescribing optimal and safe EFV doses.
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Affiliation(s)
- Milcah Dhoro
- Department of Molecular Sciences, African Institute of Biomedical Science and Technology, Dominion House, 211 Herbert Chitepo Street, P.O. Box 2294, Harare, Zimbabwe. .,Department of Clinical Pharmacology, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe.
| | - Simbarashe Zvada
- Department of Medicine, Division of Clinical Pharmacology, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa.
| | - Bernard Ngara
- Department of Molecular Sciences, African Institute of Biomedical Science and Technology, Dominion House, 211 Herbert Chitepo Street, P.O. Box 2294, Harare, Zimbabwe.
| | - Charles Nhachi
- Department of Clinical Pharmacology, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe.
| | - Gerald Kadzirange
- Department of Medicine, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe.
| | | | - Collen Masimirembwa
- Department of Molecular Sciences, African Institute of Biomedical Science and Technology, Dominion House, 211 Herbert Chitepo Street, P.O. Box 2294, Harare, Zimbabwe.
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Martín AS, Gómez AI, García-Berrocal B, Figueroa SC, Sánchez MC, Calvo Hernández MV, Gonzalez-Buitrago JM, Valverde Merino MP, Tovar CB, Martín AF, Isidoro-García M. Dose reduction of efavirenz: an observational study describing cost-effectiveness, pharmacokinetics and pharmacogenetics. Pharmacogenomics 2015; 15:997-1006. [PMID: 24956253 DOI: 10.2217/pgs.14.48] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
AIM Antiretroviral treatment implies a high cost to the healthcare system. The aim of this study was to evaluate the clinical and economic impact of efavirenz (EFV) dose adjustment by monitoring plasma concentrations and pharmacogenetic analysis of the 516G>T CYP2B6 polymorphism. MATERIALS & METHODS One hundred and ninety HIV patients treated with EFV were studied. Plasma EFV concentrations were measured by HPLC with ultraviolet detection, and pharmacogenetic analysis was performed by Real Time (RT)-PCR. RESULTS One hundred and ninety patients initially treated with a standard dose of EFV (600 mg/day) were studied. In 31 (16.3%) patients, EFV dose was reduced. A total of 87.1% of patients were heterozygous/homozygous carriers (GT/TT). CD4(+) count increased while the minimum steady-state plasma concentration and adverse effects decreased significantly after dose adjustment. Considering only the dose reduction, the adjustments accounted for a saving of 43,539 €/year. CONCLUSION The individualization of EFV dosage guided by genotyping 516G>T CYP2B6 and therapeutic drug monitoring could increase the efficiency of EFV use in antiretroviral treatment.
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De La Hoz JM, Bolaño L, Cárdenas O, González R, Sabbag J, Palacio L, Alonso LM, San-Juan-Vergara H, Cervantes-Acosta G. Characterization of treatment failure in HIV positive patients in the Colombian Caribbean region. Colomb Med (Cali) 2014; 45:162-7. [PMID: 25767304 PMCID: PMC4350381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 11/10/2014] [Accepted: 12/19/2014] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Treatment failure (TF) in patients receiving antiretroviral therapy against human immunodeficiency virus (HIV) is always a concern. OBJECTIVE To examine the correlates associated with TF in patients living in the Colombian Caribbean city of Barranquilla, an aspect that was poorly studied in this region. METHODS Treatment failure was evaluated in a cross-sectional study from virological, immunological and clinical standpoints. RESULTS It was established that 29.5% of patients under highly active antiretroviral therapy (ART) could be considered in TF. Among those, virological failure was most frequent (20.9%), followed by immunological- (14.0%) and clinical failure (4.7%). In patients showing lack of adherence to the treatment, the likelihood of suffering from TF and virogical failure were respectively increased by 6.67-fold and 12.19-fold, compared with patients showing good adherence. Although there was no statistically significant association, TF tended to be more frequent in young adults, in patients with low income and, low level of education. When ART regimens were compared, there was no apparent difference in TF between regimens based on non-nucleoside reverse transcriptase inhibitors and those based on protease inhibitors. This is very important in the context of recent ART strategies, such as early-initiated ART, aimed at achieving long-term infection control. CONCLUSIONS Is confirmed the importance of treatment adherence to avoid TF and further highlights the importance of educating HIV-infected patients in all parts of the world, especially those individuals with a lower socio-economic status.
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Affiliation(s)
| | - Laura Bolaño
- Departamento de Medicina, Universidad del Norte, Barranquilla, Colombia.
| | - Oriana Cárdenas
- Departamento de Medicina, Universidad del Norte, Barranquilla, Colombia.
| | | | - José Sabbag
- Departamento de Medicina, Universidad del Norte, Barranquilla, Colombia.
| | | | - Luz Marina Alonso
- Departamento de Salud Pública, Universidad del Norte, Barranquilla, Colombia
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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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CYP2B6 18492T->C polymorphism compromises efavirenz concentration in coinfected HIV and tuberculosis patients carrying CYP2B6 haplotype *1/*1. Antimicrob Agents Chemother 2014; 58:2268-73. [PMID: 24492364 DOI: 10.1128/aac.02384-13] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Data regarding the effect of the CYP2B6 18492T→C polymorphism on plasma efavirenz concentrations and 96-week virologic responses in patients coinfected with HIV and tuberculosis (TB) are still unavailable. A total of 139 antiretroviral-naive HIV-infected adults with active TB were prospectively enrolled to receive efavirenz 600 mg-tenofovir 300 mg-lamivudine 300 mg. Eight single nucleotide polymorphisms (SNPs) within CYP2B6 were genotyped. Seven SNPs, including 64C→T, 499C→G, 516G→T, 785A→G, 1375A→G, 1459C→T, and 21563C→T, were included for CYP2B6 haplotype determination. The CYP2B6 18492T→C polymorphism was studied in 48 patients who carried haplotype *1/*1. At 12 and 24 weeks after antiretroviral therapy, plasma efavirenz concentrations at 12 h after dosing were measured. Plasma HIV RNA was monitored every 12 weeks for 96 weeks. Of 48 patients {body weight [mean±standard deviation (SD)], 56±10 kg}, 77% received a rifampin-containing anti-TB regimen. No drug resistance-associated mutation was detected at baseline. The frequencies of the wild type (18492TT) and the heterozygous (18492TC) and homozygous (18492CC) mutants of the CYP2B6 18492T→C polymorphism were 39%, 42%, and 19%, respectively. At 12 weeks, mean (±SD) efavirenz concentrations of patients who carried the 18492TT, 18492TC, and 18492CC mutants were 2.8±1.6, 1.7±0.9, and 1.4±0.5 mg/liter, respectively (P=0.005). At 24 weeks, the efavirenz concentrations of the corresponding groups were 2.4±0.8, 1.7±0.8, and 1.2±0.4 mg/liter, respectively (P=0.003). A low efavirenz concentration was independently associated with 18492T→C (β=-0.937, P=0.004) and high body weight (β=-0.032, P=0.046). At 96 weeks, 19%, 17%, and 28% of patients carrying the 18492TT, 18492TC, and 18492CC mutants, respectively, had plasma HIV RNA levels of >40 copies/ml and developed efavirenz-associated mutations (P=0.254). In summary, the CYP2B6 18492T→C polymorphism compromises efavirenz concentrations in patients who carry CYP2B6 haplotype *1/*1 and are coinfected with HIV and tuberculosis.
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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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Sukasem C, Chamnanphon M, Koomdee N, Santon S, Jantararoungtong T, Prommas S, Puangpetch A, Manosuthi W. Pharmacogenetics and Clinical Biomarkers for Subtherapeutic Plasma Efavirenz Concentration in HIV-1 Infected Thai Adults. Drug Metab Pharmacokinet 2014; 29:289-95. [DOI: 10.2133/dmpk.dmpk-13-rg-077] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Low level of efavirenz in HIV-1-infected Thai adults is associated with the CYP2B6 polymorphism. Infection 2013; 42:469-74. [PMID: 24293076 DOI: 10.1007/s15010-013-0560-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 11/07/2013] [Indexed: 01/11/2023]
Abstract
BACKGROUND Human immunodeficiency virus type 1 (HIV-1) infections with a plasma efavirenz concentration of <1,000 ng/mL appear to have a high risk for the emergence of drug resistance. In the present study, we assessed the influence of the CYP2B6 polymorphism on the plasma efavirenz level. METHODS CYP2B6 T18492C (rs2279345) in 149 HIV-infected Thai adults were genotyped. Plasma efavirenz concentrations 12 h after dosing were measured using a validated high-performance liquid chromatography. The relationship between the plasma efavirenz level and the CYP2B6 T18492C polymorphism were analysed. RESULTS Among the 149 patients, the frequency of T18492C heterozygous (T/C) and homozygous mutant (C/C) was 38.26 % (n = 57) and 6.04 % (n = 9), respectively. In the entire cohort, the median efavirenz plasma concentration was 2,410 ng/mL [interquartile range (IQR) 1,460-4,120 ng/mL]. The plasma efavirenz concentration for patients with 18492CC (1,200 ng/mL, IQR 1,050-1,990 ng/mL) or 18492TC (1,900 ng/mL, IQR 1,320-2,510 ng/mL) genotypes were significantly lower than those with homozygous wild type (3,380 ng/mL, IQR 2,040-5,660 ng/mL), P-value < 0.001. CONCLUSIONS The CYP2B6 T18492C polymorphism was significantly associated with lower efavirenz concentrations compared to those with homozygous wild type in HIV-1 infections. The genetic polymorphism CYP2B6 T18492C may be useful for the optimised efavirenz dose. Further studies in the clinical setting will need to be conducted before such an approach can be recommended for widespread use.
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Abdelhady AM, Desta Z, Jiang F, Yeo CW, Shin JG, Overholser BR. Population pharmacogenetic-based pharmacokinetic modeling of efavirenz, 7-hydroxy- and 8-hydroxyefavirenz. J Clin Pharmacol 2013; 54:87-96. [PMID: 24142869 DOI: 10.1002/jcph.208] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 10/15/2013] [Indexed: 12/24/2022]
Abstract
The purpose of this study was to determine the demographic and pharmacogenetic covariates that influence the disposition of efavirenz (EFV) and its major metabolites. A population pharmacokinetic (PK) model was developed from a randomized, cross-over, drug-interaction study in healthy male Korean subjects (n = 17). Plasma concentrations of EFV and its hydroxy-metabolites (0-120 hours) were measured by LC/MS/MS. Genomic DNA was genotyped for variants in the cytochrome P450 (CYP) 2A6, 2B6, 3A5, and MDR1 genes. A PK model was built in a stepwise procedure using nonlinear mixed effect modeling in NONMEM 7. The covariate model was built using the generalized additive modeling and forward selection-backward elimination. Model-based simulations were performed to predict EFV steady-state concentrations following 200, 400, and 600 mg daily oral dose among different CYP2B6 genotypes. The final model included only CYP2B6 genotype as a covariate that predicts EFV clearance through the formation of 8-OH EFV that represented 65% to 80% of EFV clearance. The total clearance of EFV in CYP2B6*6/*6 genotype was ∼30% lower than CYP2B6*1/*1 or CYP2B6*1/*6 alleles (P < .001). Clopidogrel reduced both formation and elimination clearances of 8-OH EFV by 22% and 19%, respectively (P = .033 and .041). Other demographics and genotype of accessory CYP pathways did not predict EFV or metabolites PK. CYP2B6 genotype was the only significant predictor of EFV disposition. The developed model may serve as the foundation for further exploration of pharmacogenetic-based dosing of EFV.
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Affiliation(s)
- A M Abdelhady
- Department of Pharmacy Practice, College of Pharmacy, Purdue University, West Lafayette, IN, USA
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Echenique IA, Rich JD. EFV/FTC/TDF-associated hepatotoxicity: a case report and review. AIDS Patient Care STDS 2013; 27:493-7. [PMID: 23937548 DOI: 10.1089/apc.2013.0008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The fixed-dose combination efavirenz, emtricitabine, and tenofovir (EFV/FTC/TDF) is a first-line agent for the treatment of HIV. We report the case of a 40-year-old female with a history of HIV acquired through heterosexual contact who initiated EFV/FTC/TDF. Hepatitis B and C serologies were negative, CD4 cell count was 253 cells per cubic millimeter (15.8%), and HIV viral load was 67,373 copies per milliliter. Eight months later she developed transaminitis and severe right upper quadrant pain. Neither illicit drug abuse nor hepatotoxic medication such as acetaminophen was reported. After evaluation including negative acute viral hepatitis studies, EFV/FTC/TDF was discontinued; both her transaminitis and pain resolved. Hepatotoxicity is most often associated with efavirenz. Rarely, fulminant hepatic failure occurs. Efavirenz-related hepatotoxicity is thought to result from a cellular self-digestion process known as autophagy. This is the first report to our knowledge of EFV/FTC/TDF-related hepatotoxicity.
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Affiliation(s)
- Ignacio A. Echenique
- Division of Infectious Diseases, Feinberg School of Medicine of Northwestern University, Chicago, Illinois
| | - Josiah D. Rich
- Division of Infectious Diseases, The Miriam Hospital, Alpert Medical School of Brown University, Providence, Rhode Island
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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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Michaud V, Kreutz Y, Skaar T, Ogburn E, Thong N, Flockhart DA, Desta Z. Efavirenz-mediated induction of omeprazole metabolism is CYP2C19 genotype dependent. THE PHARMACOGENOMICS JOURNAL 2013; 14:151-9. [PMID: 23629159 PMCID: PMC3740059 DOI: 10.1038/tpj.2013.17] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 03/13/2013] [Accepted: 03/18/2013] [Indexed: 12/18/2022]
Abstract
Efavirenz increases CYP2C19- and CYP3A-mediated omeprazole metabolism. We hypothesized that CYP2C19 and CYP2B6 genetic polymorphisms influence the extent of induction of omeprazole metabolism by efavirenz. Healthy subjects (n=57) were administered a single 20mg oral dose of omeprazole with a single dose (600mg) or after multiple doses (600mg/day for 17 days) of efavirenz. DNA was genotyped for CYP2C19*2, *3 and *17 alleles and CYP2B6*6, *4 and *9 alleles using Taqman assays. Omeprazole, its enantiomers and metabolites were measured by LC/MS/MS. Our results showed that efavirenz increased omeprazole clearances in all CYP2C19 genotypes in non-stereoselective manner, but the magnitude of induction was genotype-dependent. Metabolic ratios of 5-hydroxylation of omeprazole were reduced in extensive and intermediate metabolizers of CYP2C19 (p<0.05). No significant associations were observed between CYP2B6 genotypes and induction by efavirenz on omeprazole metabolism. Our data indicate how interplays between drug interactions and CYP2C19 genetic variations may influence systemic exposure of CYP2C19 substrates.
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Affiliation(s)
- V Michaud
- Division of Clinical Pharmacology, Department of Medicine, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - Y Kreutz
- Division of Clinical Pharmacology, Department of Medicine, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - T Skaar
- Division of Clinical Pharmacology, Department of Medicine, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - E Ogburn
- Division of Clinical Pharmacology, Department of Medicine, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - N Thong
- Division of Clinical Pharmacology, Department of Medicine, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - D A Flockhart
- Division of Clinical Pharmacology, Department of Medicine, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - Z Desta
- Division of Clinical Pharmacology, Department of Medicine, School of Medicine, Indiana University, Indianapolis, IN, USA
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Sukasem C, Cressey TR, Prapaithong P, Tawon Y, Pasomsub E, Srichunrusami C, Jantararoungtong T, Lallement M, Chantratita W. Pharmacogenetic markers of CYP2B6 associated with efavirenz plasma concentrations in HIV-1 infected Thai adults. Br J Clin Pharmacol 2013; 74:1005-12. [PMID: 22471906 DOI: 10.1111/j.1365-2125.2012.04288.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
AIMS To investigate the frequency of CYP2B6 polymorphisms and the influence of haplotype structure on plasma efavirenz concentrations in Thai adults with HIV-1 infection. METHODS Genotyping of nine single nucleotide polymorphisms (SNPs, c.64C>T, c.499C>G, c.516G>T, c.785A>G, c.1375A>G, c.1459C>T, g.3003T>C, g.18492C>T and g.21563C>T) of CYP2B6 were performed using real-time PCR-based allelic discrimination on blood samples from 52 HIV-infected adults who had received an efavirenz-based regimen. Plasma efavirenz concentrations were measured by high performance liquid chromatography. RESULTS The minor allele frequencies for c.64C>T, c.516G>T, c.785A>G, g.3003C>T, g.18492T>C and g.21563C>T were 0.087, 0.365, 0.413, 0.308 and 0.356, respectively. However, no variant alleles were identified for three SNPs (c.499 C>G, c.1375 A>G and c.1459 C>T). Efavirenz plasma concentrations were significantly associated with c.516G>T (P= 0.0095), c.785A>G (P= 0.0017), g.21563C>T (P= 0.0036) and g.18492C>T (P= 0.0011). The composite CYP2B6 of three SNPs (c.516G ≥ T, c.785A ≥ G and g.21563C ≥ T) genotypes were significantly associated with higher efavirenz concentrations. CONCLUSIONS Our data indicate that the GAC-CYP2B6 haplotype is associated with higher plasma efavirenz concentrations in HIV-infected Thai adults.
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Affiliation(s)
- Chonlaphat Sukasem
- Laboratory for Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
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Model-based estimates of the effects of efavirenz on bedaquiline pharmacokinetics and suggested dose adjustments for patients coinfected with HIV and tuberculosis. Antimicrob Agents Chemother 2013; 57:2780-7. [PMID: 23571542 DOI: 10.1128/aac.00191-13] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Safe, effective concomitant treatment regimens for tuberculosis (TB) and HIV infection are urgently needed. Bedaquiline (BDQ) is a promising new anti-TB drug, and efavirenz (EFV) is a commonly used antiretroviral. Due to EFV's induction of cytochrome P450 3A4, the metabolic enzyme responsible for BDQ biotransformation, the drugs are expected to interact. Based on data from a phase I, single-dose pharmacokinetic study, a nonlinear mixed-effects model characterizing BDQ pharmacokinetics and interaction with multiple-dose EFV was developed. BDQ pharmacokinetics were best described by a 3-compartment disposition model with absorption through a dynamic transit compartment model. Metabolites M2 and M3 were described by 2-compartment models with clearance of BDQ and M2, respectively, as input. Impact of induction was described as an instantaneous change in clearance 1 week after initialization of EFV treatment and estimated for all compounds. The model predicts average steady-state concentrations of BDQ and M2 to be reduced by 52% (relative standard error [RSE], 3.7%) with chronic coadministration. A range of models with alternative structural assumptions regarding onset of induction effect and fraction metabolized resulted in similar estimates of the typical reduction and did not offer a markedly better fit to data. Simulations to investigate alternative regimens mitigating the estimated interaction effect were performed. The results suggest that simple adjustments of the standard regimen during EFV coadministration can prevent reduced exposure to BDQ without increasing exposures to M2. However, exposure to M3 would increase. Evaluation in clinical trials of adjusted regimens is necessary to ensure appropriate dosing for HIV-infected TB patients on an EFV-based regimen.
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Pharmacological assessment of efavirenz weight-band dosing recommendations in HIV-infected Thai children. J Acquir Immune Defic Syndr 2013; 62:e27-9. [PMID: 23262981 DOI: 10.1097/qai.0b013e3182769cd5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Sukasem C, Chamnanphon M, Koomdee N, Puangpetch A, Santon S, Jantararoungtong T, Prommas S, Chantratita W, Manosuthi W. High plasma efavirenz concentration and CYP2B6 polymorphisms in Thai HIV-1 infections. Drug Metab Pharmacokinet 2013; 28:391-7. [PMID: 23399569 DOI: 10.2133/dmpk.dmpk-12-rg-120] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Efavirenz is mainly metabolized by cytochrome P450 2B6 (CYP2B6). This study aimed to examine the frequencies of CYP2B6 and the association between CYP2B6 polymorphisms and plasma efavirenz concentrations in an HIV-1 infected Thai population. Mid-dose plasma efavirenz concentration was determined at 12 weeks following the initiation of an antiretroviral therapy (tenofovir, lamivudine and efavirenz) in 100 Thai adults with HIV-1 infection using high-performance liquid chromatography. Candidate CYP2B6 polymorphisms (c.64C>T, c.499C>G, c.516G>T, c.785A>G, c.1375A>G, c.1459C>T) were conducted by real-time PCR-based allelic discrimination. The most frequent polymorphisms among this cohort were the CYP2B6 c.785A>G and c.516G>T, which had a frequency of 0.36 and 0.32, respectively. From the cases observed, two single nucleotide polymorphisms (SNPs) (c.516G>T and c.785A>G) were significantly associated with high efavirenz plasma levels (p < 0.05). The most frequent haplotypic combinations were *1/*6, *1/*1, *1/*2 and *6/*6 at a frequency of 42.0%, 32.0%, 8.0% and 7.0%, respectively. Increased plasma concentrations of efavirenz were present in individuals with CYP2B6 *6/*6 [7.210 mg/L; interquartile range (IQR), 5.020-9.260] when compared to those with CYP2B6*1/*1 (1.570 mg/L; IQR, 1.295-2.670), p < 0.001. In our study, the impact of SNPs which are correlated with a high level of efavirenz plasma concentrations was found. The genetic configuration of SNPs which are associated with high plasma efavirenz levels may be useful in optimizing the efavirenz dose that is used in HIV-1 infected patients.
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Affiliation(s)
- Chonlaphat Sukasem
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University
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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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Long-Term Efficacy and Safety of Efavirenz Dose Reduction to 200 mg Once Daily in a Caucasian Patient with HIV. Clin Drug Investig 2012; 30:405-11. [DOI: 10.1007/bf03256910] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Gandhi M, Greenblatt RM, Bacchetti P, Jin C, Huang Y, Anastos K, Cohen M, Dehovitz JA, Sharp GB, Gange SJ, Liu C, Hanson SC, Aouizerat B. A single-nucleotide polymorphism in CYP2B6 leads to >3-fold increases in efavirenz concentrations in plasma and hair among HIV-infected women. J Infect Dis 2012; 206:1453-61. [PMID: 22927450 DOI: 10.1093/infdis/jis508] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Efavirenz exhibits marked interindividual variability in plasma levels and toxicities. Prior pharmacogenetic studies usually measure exposure via single plasma levels, examine limited numbers of polymorphisms, and rarely model multiple contributors. We analyzed numerous genetic and nongenetic factors impacting short-term and long-term exposure in a large heterogeneous population of human immunodeficiency virus (HIV)-infected women. METHODS We performed 24-hour intensive pharmacokinetic studies in 111 women receiving efavirenz under actual-use conditions and calculated the area-under-the-concentration-time curve (AUC) to assess short-term exposure; the efavirenz concentration in hair was measured to estimate long-term exposure. A total of 182 single-nucleotide polymorphisms (SNPs) and 45 haplotypes in 9 genes were analyzed in relationship to exposure by use of multivariate models that included a number of nongenetic factors. RESULTS Efavirenz AUCs increased 1.26-fold per doubling of the alanine aminotransferase level and 1.23-fold with orange and/or orange juice consumption. Individuals with the CYP2B6 516TT genotype displayed 3.5-fold increases in AUCs and 3.2-fold increases in hair concentrations, compared with individuals with the TG/GG genotype. Another SNP in CYP2B6 (983TT) and a p-glycoprotein haplotype affected AUCs without substantially altering long-term exposure. CONCLUSIONS This comprehensive pharmacogenomics study showed that individuals with the CYP2B6 516TT genotype displayed >3-fold increases in both short-term and long-term efavirenz exposure, signifying durable effects. Pharmacogenetic testing combined with monitoring of hair levels may improve efavirenz outcomes and reduce toxicities.
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Affiliation(s)
- Monica Gandhi
- Department of Medicine, University of California, San Francisco, CA, USA.
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Siccardi M, Almond L, Schipani A, Csajka C, Marzolini C, Wyen C, Brockmeyer NH, Boffito M, Owen A, Back D. Pharmacokinetic and Pharmacodynamic Analysis of Efavirenz Dose Reduction Using an In Vitro–In Vivo Extrapolation Model. Clin Pharmacol Ther 2012; 92:494-502. [DOI: 10.1038/clpt.2012.61] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Michaud V, Bar-Magen T, Turgeon J, Flockhart D, Desta Z, Wainberg MA. The Dual Role of Pharmacogenetics in HIV Treatment: Mutations and Polymorphisms Regulating Antiretroviral Drug Resistance and Disposition. Pharmacol Rev 2012; 64:803-33. [DOI: 10.1124/pr.111.005553] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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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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Galván CA, Elbarcha OC, Fernández EJ, Beltramo DM, Soria NW. Distribution of polymorphisms in cytochrome P450 2B6, histocompatibility complex P5, chemokine coreceptor 5, and interleukin 28B genes in inhabitants from the central area of Argentina. Genet Test Mol Biomarkers 2012; 16:130-3. [PMID: 21854194 DOI: 10.1089/gtmb.2011.0058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
AIMS The selection of the most appropriate treatment for several diseases relies on a number of factors such as environment, age, gender, and nutrition. Additionally, the contribution of different genetic polymorphisms to treatment efficacy has been largely recognized. The lack of information on the pharmacogenetic profile of our population prompted us to analyze the frequency of polymorphisms known to be relevant to achieve treatment efficacy with different therapeutic agents in viral infectious diseases, such as Hepatitis C and AIDS. RESULTS The allelic frequencies for the wild-type variant of the genes analyzed were cytochrome P450 2B6 (CYP2B6; rs3745274; 516G) 0.618 (95% confidence interval [CI]: 0.523, 0.711), chemokine coreceptor 5 (CCR5; rs333) 0.961 (95% CI: 0.942, 0.98), histocompatibility complex P5 (HCP5; rs2395029; 335T) 0.971 (95% CI: 0.937, 1), and interleukin 28B (IL28B; rs12979860; 12007005C) 0.656 (95% CI: 0.564, 0.747), respectively. CONCLUSIONS Our data indicate that the genetic profile of the population studied is similar to that reported for other Caucasian populations, with only slight differences for CYP2B6. Noteworthy, the considerable number of patients carrying CYP2B6 (516T) and IL28B (12007005T) alleles underlies the importance of considering pharmacogenetic testing before starting drug therapy protocols to prevent toxicity and/or lack of effectiveness in AIDS or hepatitis C virus infections.
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López Aspiroz E, Cabrera Figueroa SE, Domínguez-Gil Hurlé A, García Sánchez MJ. [New strategies in the optimisation of lopinavir/ritonavir doses in human immunodeficiency virus-infected patients]. Enferm Infecc Microbiol Clin 2012; 31:36-43. [PMID: 22280562 DOI: 10.1016/j.eimc.2011.11.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 11/21/2011] [Accepted: 11/28/2011] [Indexed: 01/11/2023]
Abstract
Lopinavir/ritonavir (LPV/r) has demonstrated virological and immunological efficacy in the combined antiretroviral treatment (cART), in both naïve and experienced patients. Furthermore, LPV/r showed a high barrier to the development of resistance. Although generally well tolerated, adverse gastrointestinal side effects and metabolic disorders are frequent. The different tools used to optimise the cART with this drug combination in the daily clinical practice, emphasising the therapeutic drug monitoring (TDM) of LPV/r and the genetic analysis of the main enzymes responsible for the metabolism and transport, are reviewed. The relationship between phenotype and genotype, established through TDM, could be useful for the physician to improve the clinical management of the HIV infection, due to the possibility of individualising the dose with this drug. Monotherapy is also reviewed as a new strategy used in the simplification of the treatment with this drug, which could increase safety and reduce costs.
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Affiliation(s)
- Elena López Aspiroz
- Servicio de Farmacia, Hospital Universitario de Salamanca, Salamanca, España
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Population pharmacokinetics of lopinavir/ritonavir (Kaletra) in HIV-infected patients. Ther Drug Monit 2012; 33:573-82. [PMID: 21912331 DOI: 10.1097/ftd.0b013e31822d578b] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND A relationship between plasma concentrations and viral suppression in patients receiving lopinavir (LPV)/ritonavir (RTV) has been observed. Therefore, it is important to increase our knowledge about factors that determine interpatient variability in LPV pharmacokinetics (PK). METHODS The study, designed to develop and validate population PK models for LPV and RTV, involved 263 ambulatory patients treated with 400/100 mg of LPV/RTV twice daily. A database of 1110 concentrations of LPV and RTV (647 from a single time-point and 463 from 73 full PK profiles) was available. Concentrations were determined at steady state using high-performance liquid chromatography with ultraviolet detection. PK analysis was performed with NONMEM software. Age, gender, height, total body weight, body mass index, RTV trough concentration (RTC), hepatitis C virus coinfection, total bilirubin, hospital of origin, formulation and concomitant administration of efavirenz (EFV), saquinavir (SQV), atazanavir (ATV), and tenofovir were analyzed as possible covariates influencing LPV/RTV kinetic behavior. RESULTS Population models were developed with 954 drug plasma concentrations from 201 patients, and the validation was conducted in the remaining 62 patients (156 concentrations). A 1-compartment model with first-order absorption (including lag-time) and elimination best described the PK. Proportional error models for interindividual and residual variability were used. The final models for the drugs oral clearance (CL/F) were as follows: CL/F(LPV)(L/h)=0.216·BMI·0.81(RTC)·1.25(EFV)·0.84(ATV); CL/F(RTV)(L/h) = 8.00·1.34(SQV)·1.77(EFV)·1.35(ATV). The predictive performance of the final population PK models was tested using standardized mean prediction errors, showing values of 0.03 ± 0.74 and 0.05 ± 0.91 for LPV and RTV, and normalized prediction distribution error, confirming the suitability of both models. CONCLUSIONS These validated models could be implemented in clinical PK software and applied to dose individualization using a Bayesian approach for both drugs.
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Semvua HH, Kibiki GS. AtriplaR/anti-TB combination in TB/HIV patients. Drug in focus. BMC Res Notes 2011; 4:511. [PMID: 22114934 PMCID: PMC3236078 DOI: 10.1186/1756-0500-4-511] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 11/24/2011] [Indexed: 12/16/2022] Open
Abstract
Background Co-administration of anti-tuberculosis and antiretroviral therapy is often inevitable in high-burden countries where tuberculosis is the most common opportunistic infection associated with HIV/AIDS. Concurrent use of rifampicin and several antiretroviral drugs is complicated by pharmacokinetic drug-drug interaction. Method Pubmed and Google search following the key words tuberculosis, HIV, emtricitabine, tenofovir efavirenz, interaction were used to find relevant information on each drug of the fixed dose combination AtriplaR Results Information on generic name, trade name, pharmacokinetic parameter, metabolism and the pharmacokinetic interaction with Anti-TB drugs of emtricitabine, tenofovir, and efavirenz was obtained. Conclusion Fixed dose combination of emtricitabine/tenofovir/efavirenz (ATRIPLAR) which has been approved by Food and Drug Administration shows promising results as far as safety and efficacy is concerned in TB/HIV co-infection patients, hence can be considered effective and safe antiretroviral drug in TB/HIV management for adult and children above 3 years of age.
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Affiliation(s)
- Hadija H Semvua
- Kilimanjaro Clinical Research Institute (KCRI), Kilimanjaro Christian Medical Centre (KCMC), P,O Box 2236, Moshi-Kilimanjaro, Tanzania.
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Viljoen M, Karlsson MO, Meyers TM, Gous H, Dandara C, Rheeders M. Influence of CYP2B6 516G>T polymorphism and interoccasion variability (IOV) on the population pharmacokinetics of efavirenz in HIV-infected South African children. Eur J Clin Pharmacol 2011; 68:339-47. [PMID: 22057858 DOI: 10.1007/s00228-011-1148-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 10/14/2011] [Indexed: 01/11/2023]
Abstract
OBJECTIVE To investigate the influence of CYP2B6 516G>T polymorphism, as a covariate, and of interoccasion variability (IOV) on the oral clearance (CL/F) of efavirenz (EFV) in treatment-naïve black South African children over a period of 24 months post-antiretroviral therapy (ART) initiation. METHODS HIV-infected black children (n = 60, aged 3-16 years), with no prior exposure to ART, eligible to commence ART and attending an outpatient clinic were enrolled into this study. Blood samples were taken at mid-dose interval at 1, 3, 6, 12, 18 and 24 months post-ART initiation. EFV plasma samples were determined with an adapted and validated LC/MS/MS method. Genotyping of the CYP2B6 G516T single nucleotide polymorphism (SNP) was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). NONMEM was used for the population pharmacokinetic modelling. RESULTS EFV concentrations below 1 μg/mL accounted for 18% (116/649), EFV concentrations >4 μg/mL accounted for 29.5% (192/649) and concentrations within the therapeutic range (1-4 μg/mL) represented 52.5% (341/649) of all the samples determined. The covariates age, weight and CYP2B6 G516Tgenotype were included in the final model with population estimates for CL/F determined as 2.46, 4.60 and 7.33 L/h for the T/T, G/T and G/G genotype groups respectively. CONCLUSIONS The inclusion of both age and weight to predict accurate EFV CL values for the respective genotype groups within this paediatric population was required, whereas the addition of gender and body surface area did not improve the predictions. The importance of introducing IOV in a PK model for a longitudinal study with sparsely collected data was again highlighted by this investigation.
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Affiliation(s)
- M Viljoen
- Unit for Drug Research and Development, Division of Pharmacology, School of Pharmacy, North-West University, Potchefstroom, South Africa.
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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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Habtewold A, Amogne W, Makonnen E, Yimer G, Riedel KD, Ueda N, Worku A, Haefeli WE, Lindquist L, Aderaye G, Burhenne J, Aklillu E. Long-term effect of efavirenz autoinduction on plasma/peripheral blood mononuclear cell drug exposure and CD4 count is influenced by UGT2B7 and CYP2B6 genotypes among HIV patients. J Antimicrob Chemother 2011; 66:2350-61. [DOI: 10.1093/jac/dkr304] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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Solas C, Gagnieu MC. [Evidence-based therapeutic drug monitoring for efavirenz]. Therapie 2011; 66:197-205. [PMID: 21819803 DOI: 10.2515/therapie/2011033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 03/08/2011] [Indexed: 01/11/2023]
Abstract
The efavirenz, a non nucleoside reverse transcriptase inhibitor of HIV-1, presents a marked pharmacokinetics variability related to an intense hepatic metabolism. Efavirenz is also a potent inducer. Central nervous system (CNS) toxicity associated with efavirenz therapy is a major cause of non adherence and therefore treatment failure. The literature has been analyzed to evaluate the level of evidence of the interest of a therapeutic drug monitoring for efavirenz. Several studies have reported that an efavirenz plasma concentration >1 000 ng/mL is a predictive factor of the viral response. Efavirenz plasma concentrations >4 000 ng/mL were associated to an increase frequency of CNS side effects. CNS toxicity was also more frequent in patients carrying the 516G > T mutation (CYP2B6*6 allele), associated with a significantly greater efavirenz plasma exposure. Non-randomized studies have reported the interest of efavirenz therapeutic drug monitoring to optimize viral response and prevent CNS toxicity, allowing to suggest a level of evidence "recommended" for efavirenz.
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Affiliation(s)
- Caroline Solas
- Laboratoire de Pharmacocinétique et Toxicologie, Hôpital de La Timone, Marseille, France.
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Ngaimisi E, Mugusi S, Minzi O, Sasi P, Riedel KD, Suda A, Ueda N, Janabi M, Mugusi F, Haefeli WE, Bertilsson L, Burhenne J, Aklillu E. Effect of rifampicin and CYP2B6 genotype on long-term efavirenz autoinduction and plasma exposure in HIV patients with or without tuberculosis. Clin Pharmacol Ther 2011; 90:406-13. [PMID: 21814190 DOI: 10.1038/clpt.2011.129] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We performed a prospective comparative study to examine, from a pharmacogenetics perspective, the effect of rifampicin (RIF) on long-term efavirenz (EFV) autoinduction and kinetics. In a study population of patients with HIV receiving EFV with RIF (arm 2, n = 54) or without RIF (arm 1, n = 128 controls), intraindividual and interindividual plasma EFV and 8-hydroxyefavirenz levels were compared at weeks 4 and 16 of EFV therapy. In arm 2, RIF was initiated 4 weeks before starting EFV. In controls (arm 1), the plasma EFV was significantly lower whereas 8-hydroxyefavirenz was higher at week 16 as compared to week 4. By contrast, there were no significant differences in plasma EFV and 8-hydroxyefavirenz concentrations over time in arm 2. At week 4, the plasma EFV concentration was significantly lower in arm 2 as compared to arm 1, but no significant differences were observed by week 16. When stratified by CYP2B6 genotype, significant differences were observed only with respect to CYP2B6*1/*1 genotypes. Ours is the first report of the CYP2B6 genotype-dependent effect of RIF on long-term EFV autoinduction.
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Affiliation(s)
- E Ngaimisi
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska University Hospital-Huddinge, Karolinska Institute, Stockholm, Sweden
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