Single dose pharmacokinetics and bioavailability of nevirapine in healthy volunteers

The results of two randomized, single-dose, crossover bioavailability studi es are presented which describe the pharmacokinetics and oral bioavailabili ty of nevirapine, a novel nonnucleoside antiretroviral drug. In the first s tudy 12. healthy male volunteers received nevirapine 15 mg via short-term i .v. infusion or orally as a 50 mg tablet or reference solution (50 mg/200 m L). Following the i.v. dose, nevirapine had a low systemic clearance (Mean +/- S.D., Cl = 1.4 +/- 0.3 L/h) and a prolonged elimination phase (t(1/2 be ta) = 52.8 +/- 14.8 h; MRT = 81.4 +/- 22.4 h). Nevirapine absolute bioavail ability was 93 +/- 9% and 91 +/- 8% for the tablet and oral solution, respe ctively. In the second study, 24 healthy male volunteers were administered nevirapine as a 200 mg production-line tablet or oral reference solution (2 00 mg/200 mL). There was no significant difference in bioavailability betwe en the tablet and reference solution. Overall, comparison of the pharmacoki netic parameters between the 50 and 200 mg doses indicates that nevirapine is well absorbed at clinically relevant doses. The absorption profiles usin g deconvolution revealed no evidence of differential enzyme induction betwe en the two doses or routes of administration following a single dose. Copyr ight (C) 1999 John Wiley & Sons, Ltd.