OBJECTIVES: The aim of the study was to characterize the impact of the cytochrome P450 2B6 (CYP2B6), CYP3A4, CYP3A5 and ATP-binding cassette sub-family B member 1 (ABCB1) polymorphisms on nevirapine plasma concentrations. METHODS: A total of 104 patients (82% male; 26% non-Caucasian) were genotyped for eight single nucleotide polymorphisms at four loci (CYP2B6, CYP3A4, CYP3A5 and MDR1). Nevirapine plasma concentrations were determined using high-performance liquid chromatography. RESULTS: Non-Caucasian ethnicity [5609 ng/mL (n=27) for non-Caucasians vs. 3771 ng/mL (n=77) for Caucasians; P<0.0001] and CYP2B6 516G-->T [GG, 3574 ng/mL (n=50); GT, 4634 ng/mL (n=50); TT, 8170 ng/mL (n=4); P(analysis of variance (anova))=0.001] were significantly associated with a higher nevirapine trough concentration (C(trough)). The latter association was maintained with both 200 mg twice daily (bid) and 400 mg once daily (qd) dosing [GG, 3527 ng/mL (n=30); GT, 4525 ng/mL (n=32); TT, 7020 ng/mL (n=2); P(anova)=0.05 and GG, 3645 ng/mL (n=20); GT, 4861 ng/mL (n=17); TT, 9508 ng/mL (n=2); P(anova)=0.01, respectively]. In a multivariable analysis, CYP2B6 516G-->T and non-Caucasian ethnicity remained significant predictors of nevirapine C(trough) but CYP2B6 516G-->T homozygosity had the greatest effect (108% higher, 46% higher). No associations were found between nevirapine C(trough) and the remaining polymorphisms. CONCLUSION: In this population, both non-Caucasian ethnicity and carriage of the variant allele of CYP2B6 516G-->T were significant predictors of nevirapine C(trough). The association between CYP2B6 516G-->T and higher plasma nevirapine exposure was maintained at both bid and qd dosing.
OBJECTIVES: The aim of the study was to characterize the impact of the cytochrome P450 2B6 (CYP2B6), CYP3A4, CYP3A5 and ATP-binding cassette sub-family B member 1 (ABCB1) polymorphisms on nevirapine plasma concentrations. METHODS: A total of 104 patients (82% male; 26% non-Caucasian) were genotyped for eight single nucleotide polymorphisms at four loci (CYP2B6, CYP3A4, CYP3A5 and MDR1). Nevirapine plasma concentrations were determined using high-performance liquid chromatography. RESULTS: Non-Caucasian ethnicity [5609 ng/mL (n=27) for non-Caucasians vs. 3771 ng/mL (n=77) for Caucasians; P<0.0001] and CYP2B6 516G-->T [GG, 3574 ng/mL (n=50); GT, 4634 ng/mL (n=50); TT, 8170 ng/mL (n=4); P(analysis of variance (anova))=0.001] were significantly associated with a higher nevirapine trough concentration (C(trough)). The latter association was maintained with both 200 mg twice daily (bid) and 400 mg once daily (qd) dosing [GG, 3527 ng/mL (n=30); GT, 4525 ng/mL (n=32); TT, 7020 ng/mL (n=2); P(anova)=0.05 and GG, 3645 ng/mL (n=20); GT, 4861 ng/mL (n=17); TT, 9508 ng/mL (n=2); P(anova)=0.01, respectively]. In a multivariable analysis, CYP2B6 516G-->T and non-Caucasian ethnicity remained significant predictors of nevirapine C(trough) but CYP2B6 516G-->T homozygosity had the greatest effect (108% higher, 46% higher). No associations were found between nevirapine C(trough) and the remaining polymorphisms. CONCLUSION: In this population, both non-Caucasian ethnicity and carriage of the variant allele of CYP2B6 516G-->T were significant predictors of nevirapine C(trough). The association between CYP2B6 516G-->T and higher plasma nevirapine exposure was maintained at both bid and qd dosing.
Authors: Rajeev K Mehlotra; Vinay K Cheruvu; Melinda J Blood Zikursh; Rebekah L Benish; Michael M Lederman; Robert A Salata; Barbara Gripshover; Grace A McComsey; Michelle V Lisgaris; Scott Fulton; Carlos S Subauste; Richard J Jurevic; Chantal Guillemette; Peter A Zimmerman; Benigno Rodriguez Journal: J Infect Dis Date: 2011-07-15 Impact factor: 5.226
Authors: Kevin C Brown; Mina C Hosseinipour; Janelle M Hoskins; Ranjit K Thirumaran; Hsiao-Chuan Tien; Ralf Weigel; Jean Tauzie; Ida Shumba; Jatinder K Lamba; Erin G Schuetz; Howard L McLeod; Angela D M Kashuba; Amanda H Corbett Journal: Pharmacogenomics Date: 2011-11-23 Impact factor: 2.533
Authors: Neill J Liptrott; Sudeep Pushpakom; Christoph Wyen; Gerd Fätkenheuer; Christian Hoffmann; Stefan Mauss; Heribert Knechten; Norbert H Brockmeyer; Elizabeth Hopper-Borge; Marco Siccardi; David J Back; Saye H Khoo; Munir Pirmohamed; Andrew Owen Journal: Pharmacogenet Genomics Date: 2012-01 Impact factor: 2.089
Authors: Saran Vardhanabhuti; Edward P Acosta; Heather J Ribaudo; Patrice Severe; Umesh Lalloo; Nagalingeshwaran Kumarasamy; Frank Taulo; Joseph Kabanda; Olola Oneko; Prudence Ive; Pradeep Sambarey; Ellen S Chan; Jane Hitti; Francis Hong; Deborah McMahon; David W Haas Journal: J Infect Dis Date: 2013-05-17 Impact factor: 5.226