A randomized controlled trial of fluoxetine in the treatment of cocaine dependence among methadone-maintained patients

Background: Cocaine abuse and dependence continue to be widespread. Currently, there are no pharmacotherapies shown to be effective in the treatment of cocaine dependence. Methods: A 33-week outpatient clinical trial of fluoxetine (60 mg/day, po) for cocaine dependence that incorporated abstinence-contingent voucher incentives was conducted. Participants (N = 145) were both cocaine and opioid dependent and treated with methadone. A stratified randomization procedure assigned subjects to one of four conditions: fluoxetine plus voucher incentives (FV), placebo plus voucher incentives (PV), fluoxetine without vouchers (F), and placebo without vouchers (P). Dosing of fluoxetine/placebo was double blind. Primary outcomes were treatment retention and cocaine use based on thrice-weekly urine testing. Results: The PV group had the longest treatment retention (M = 165 days) and lowest probability of cocaine use. The adjusted predicted probabilities of cocaine use were 65% in the P group, 60% in the F group, 56% in the FV group, and 31% in the PV group. Conclusions: Fluoxetine was not efficacious in reducing cocaine use in patients dually dependent on cocaine and opioids.