The pharmacokinetics of methadone in HIV‐positive patients receiving the non‐nucleoside reverse transcriptase inhibitor efavirenz

Abstract

The inclusion of the NNRTI efavirenz in once daily ART for HIV patients with a history of IDU receiving methadone maintenance results in a significant reduction in methadone plasma concentrations mediated by enzyme induction. It is important to distinguish efavirenz neurological effects which were observed between days 1-5 of therapy from symptoms of methadone withdrawal which occurred from day 8 onwards. The dose of methadone was adjusted by increments of 10 mg to counteract the efavirenz inducing effect.