The effects of once-daily saquinavir/minidose ritonavir on the pharmacokinetics of methadone.

Twelve methadone-maintained HIV-negative subjects were given saquinavir/ritonavir (SQV/rtv) 1600 mg/100 mg once daily for 14 days. Pharmacokinetic evaluations of total and unbound methadone enantiomers (R and S) were conducted before and after SQV/rtv. SQV/rtv was well tolerated, with no ACTG Grade 3-4 adverse events, no evidence of sedation, and no changes in methadone dose.