Evaluation of nevirapine dosing recommendations in HIV-infected children.

Aims Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor used for chronic human immunodeficiency virus infections in adults and children. The aims of this study were to investigate the population pharmacokinetics of NVP in children, establish factors that influence NVP pharmacokinetics and evaluate the current dosing recommendations. Methods Concentrations were measured on a routine basis in 94 children aged from 2 months to 17 years. A total of 390 NVP plasma concentrations were retrospectively collected, and a population pharmacokinetic model was developed with Monolix 4.0. Results Nevirapine pharmacokinetics was best described by a one-compartment model with first-order absorption and elimination. After standardization to a 70 kg adult using allometry, postmenstrual age had a significant effect on the bioavailability. Estimates of apparent clearance and volume of distribution were 3.9 l h−1 (70 kg)−1 and 140 l (70 kg)−1, respectively. Based on simulations of European Medicines Agency (EMA) and World Health Organization (WHO) dosing recommendations, the probability of observing minimal concentrations below the efficacy target of 3 mg l−1 is higher following the EMA recommendations than the WHO recommendations. However, NVP underdosing persists for the 3–6 and 6–10 kg weight ranges following the WHO recommendations. Conclusions It is suggested to increase doses to 75 and 100 mg twice daily for the 3–6 and 6–10 kg weight ranges, respectively, in order to obtain more than 95% of children with concentrations above 3 mg l−1.