Ten HIV-1 infected, opioid-dependent adults on stable methadone treatment were to be enrolled in this study. This was an open-label, sequential treatment study, with methadone pharmacokinetics sampling before and after twenty-one (21) days of nevirapine administration.~All patients received the same regimen. Methadone was administered in the first treatment period, and combination treatment of methadone and nevirapine was given in the second treatment period. In the first period, patients received methadone at their current steady state dose. In the second period (study days 1-21), they also received nevirapine 200mg qd (study days 1 to 14) and 200mg bid (study days 15 to 21). Blood samples were taken at the start of the first treatment period and at the end of the second treatment period for analysis of methadone and nevirapine pharmacokinetics parameters.~Study Hypothesis:~It was expected that nevirapine would decrease methadone levels in this patient population.~Comparison(s):~The study compared methadone steady state exposure in the absence and presence of steady state nevirapine. A range of pharmacokinetics parameters were assessed including clearance of methadone (the primary endpoint variable), area under the concentration-time curve, maximum concentration, time to maximum concentration and minimum concentration (measured for both methadone and nevirapine).
The purpose of this study was to determine the effects of nevirapine treatment on the pharmacokinetics of methadone in HIV-1 infected, opioid-dependent adults who had been on a stable methadone maintenance therapy for at least five days prior to study entry.