Sex differences in nevirapine disposition in HIV-infected patients.

To evaluate the role of sex in nevirapine pharmacokinetics, we analysed the pharmacokinetic profile of nevirapine in 11 male and 11 female HIV-positive patients chronically treated with nevirapine 400 mg once a day. Statistically significant inter-group differences in the plasma concentration and fluctuations between that and the concentration just before the next dose, at steady-state, were observed. Variations in lean body mass and composition affecting nevirapine distribution might account for inter-sex discrepancies in nevirapine plasma levels.