This is a randomized, open-label, multi-center, Phase 4 study to assess the changes in liver enzymes related to treatment with buprenorphine/naloxone (BUP/NX) and methadone (MET) in participants entering opioid agonist treatment. Randomization will be stratified, within site, according to normal versus abnormal screening liver function tests. Participants meeting entry criteria will be dosed for 24 weeks during the active phase of the study with assessment of liver function at weeks 1, 2, 4, 8, 12, 16, 20, 24 and with follow-up assessments at week 32. Clinicians will be encouraged to treat with adequate doses of BUP/NX and MET.
The Food and Drug Administration (FDA) has requested a study comparing buprenorphine/naloxone (BUP/NX) and methadone (MET) on indices of hepatic safety.