A total of 120 male and female opioid dependent cocaine users will participate in this study.
This study will be a 8-week double-blind, placebo controlled study examining the
dose-dependent effects of carvedilol (up to 50 mg/day) in methadone stabilized patients. The
design will have two phases: 1) a four-week "treatment " phase; and 2) a 4 week " taper and
detoxification or transfer" phase. Subjects will be cocaine users who are on stable doses of
methadone (60 to 140 mg/day). Carvedilol dose will be increased from 12.5mg/day to the target
dose of either 25 or 50 mg/day as tolerated. At the end of the treatment-phase, subjects will
undergo detoxification from methadone over a 2 to 4-week period based on an individual's
needs, and they will concurrently be tapered off carvedilol.