Background:  We assessed the pharmacokinetics of single-dose of generic nevirapine (NVP) and the effect of rifampicin on hepatic induction on the same among healthy Indian male volunteers.

Methods:  NVP levels were estimated among 12 healthy, consenting male volunteers after taking a single dose of 200 mg. Blood samples were collected for serum drug concentration analysis at the following times relative to dose administration:  0, 0.5, 1, 1.5, 2.0, 4.0, 6.0, 12.0, 24.0, 48.0, 72.0, and 336.0 hours after the dose. NVP concentrations were measured by a sensitive, validated, reversed-phase high-performance liquid chromatographic assay. After a washout period of 3 weeks, standard doses of rifampin (according to weight) were taken for 7 days. Repeat NVP-level measurements were done after a single 200-mg dose. The highest serum drug concentration over dose interval (C_max), the concentration at 24 hours (C₂₄, timing for next dose), AUC_0-t, and half life (T_½) were obtained from individual concentration time profiles. The differences in the C_max, C₂₄ AUC_0-t, and T_½ before and after rifampin induction were assessed by paired t-test.

Results:  The table depicts the effect of rifampin induction on NVP levels. None of the volunteers developed a serious adverse event during the study period.

Conclusions:  The pharmacokinetics of single-dose NVP among healthy Indian volunteers is similar to that reported from other racial populations across the world. Rifampicin induction significantly alters the pharmacokinetic profile of NVP in this population, and concurrent use should not be recommended.