A systematic review and meta-analysis of medications for stimulant use disorders in patients with co-occurring opioid use disorders

Background: Stimulant (cocaine and/or methamphetamine) use has increased among people with opioid use disorder. We conducted a systematic review of medications for stimulant use disorders in this population. Methods: We searched for randomized controlled trials in multiple databases through April 2019, and dual-screened studies using pre-specified inclusion criteria. Primary outcomes were abstinence defined as stimulant-negative urine screens for ≥3 consecutive weeks; overall use as the proportion of stimulant-negative urine specimens; and retention as the proportion of participants who completed treatment. We rated strength of evidence using established criteria and conducted meta-analyses of comparable interventions and outcomes. Results: Thirty-four trials of 22 medications focused on cocaine use disorder in patients with opioid use disorder. Most studies enrolled participants stabilized on opioid maintenence therapy, generally methadone. None of the six studies that assessed abstinence found significant differences between groups. We found moderate-strength evidence that antidepressants (desipramine, bupropion, and fluoxetine) worsened retention. There was moderate-strength evidence that disulfiram worsened treatment retention (N = 605, RR 0.86, 95 % CI 0.77 to 0.95). We found low-strength evidence that psychostimulants (mazindol and dexamphetamine) may reduce cocaine use, though the difference was not statistically significant (standard mean difference 0.35 [95 % CI -0.05 to 0.74]). There was only 1 trial for methamphetamine use disorder, which showed insufficient-strength evidence for naltrexone. Conclusions: Co-occurring stimulant/opioid use disorder is an important problem for targeting future research. Medication trials for methamphetamine use disorder are lacking in this population. Most of the medications studied for cocaine use were ineffective, although psychostimulants warrant further study.