Background/aim: Nevirapine is a reverse-transcriptase inhibitor widely used in combination therapy to treat HIV infection. Nevirapine is extensively metabolized in the liver and CYP2B6 is mainly responsible for oxidation of 3-hydroxynevirapine (3-OH NVP). This study aims to explore CYP2B6 activity by measuring 2-hydroxynevirapine (2-OH NVP) and 3-OH NVP in plasma and to identify factors associated with nevirapine pharmacokinetic parameters. Materials and methods: A total of 112 patients were recruited and treated with nevirapine-based antiretroviral therapy. Plasma nevirapine and metabolite concentrations were assayed using high-performance liquid chromatography via liquid-liquid extraction. Results: Thirty-nine (34.8%) of the patients had no 3-OH NVP detected in their plasma while 2-OH NVP was detected in all patients. Metabolite concentrations were low compared to nevirapine. Positive correlations were observed between nevirapine and its metabolites, 2-OH NVP (P < 0.01) and 3-OH NVP (P = 0.012). Nevirapine concentration was decreased when concomitantly administered with methadone. Univariate analysis showed that ALT level, AST level, and detection of 3-OH NVP were associated with nevirapine pharmacokinetic parameters. Conclusion: The variability of nevirapine pharmacokinetic parameters was caused by liver enzymes and the presence of 3-OH NVP metabolites. The presence of 3-OH NVP can probably be used to distinguished CYP2B6 activity and efficacy of nevirapine in patients with HIV infection.
MUSTAFA, SUZANA; HASSAN, NORUL BADRIAH; TAN, SOO CHOON; MUSTAFA, MAHIRAN; RAHMAN, AHMAD KASHFI AB; LOW, LEE LEE; and YUSUF, WAN NAZIRAH WAN
"Exploring CYP2B6 activity by measuring the presence ofnevirapine hydroxy metabolites in plasma,"
Turkish Journal of Medical Sciences: Vol. 46:
6, Article 42.
Available at: https://journals.tubitak.gov.tr/medical/vol46/iss6/42