Bupropion Slow Release vs Placebo with Adaptive Incentives for Cocaine Use Disorder in Persons Receiving Methadone for Opioid Use Disorder: A Randomized Clinical Trial

Abstract

Importance: Opioid-stimulant co-use is a common problem with few evidence-based treatments. Objective: To examine bupropion slow release (SR) enhancement of a tailored abstinence incentive program for stimulant use in persons with opioid use disorder. Design, Setting, and Participants: This 26-week, double-blind, placebo-controlled randomized clinical trial with a 4-week follow-up period was conducted at 4 methadone treatment programs in Baltimore, Maryland. Included participants were persons receiving methadone for the treatment of opioid use disorder with past 3-month cocaine use and current cocaine use disorder between March 2015 and September 2019. Data were analyzed from November 2020 through August 2022. Interventions: A 6-week incentive induction period with monetary incentives for evidence of cocaine abstinence during thrice-weekly urine testing was conducted. Persons achieving 2 weeks of consecutive abstinence during induction were assigned to the relapse prevention group (20 individuals); otherwise, individuals were assigned to the abstinence initiation group (60 individuals). Participants were randomized within incentive groups to bupropion SR (150 mg oral twice daily; 40 participants) or placebo (40 participants). Incentives were available until week 26, and study medication ended week 30. Main Outcomes and Measures: The mean percentage of participants with cocaine abstinence (by negative urinalysis or self-report) during weeks 7 to 26 (ie, the incentive intervention period) and 27 to 30 (ie, the follow-up period) and the percentage of participants testing negative for cocaine at weeks 26 and 30 were assessed. Main effects of medication collapsed across incentive conditions and sensitivity analyses of medications within incentive conditions were assessed. Analyses were conducted in the modified intention-to-treat sample (ie, 80 individuals who received ≥1 dose of study medication) and completers (ie, 52 individuals who completed ≥1 visit during week 30). Results: Among 80 participants (42 Black [52.5%] and 35 White [43.8%]; mean [SD] age, 45.7 (9.4) years; 52 males [65.0%]) receiving methadone for opioid use disorder, 40 participants were randomized to receive bupropion SR and 40 participants to receive placebo. No significant difference on urinalysis or self-reported cocaine use was observed between medication groups. Sensitivity analyses revealed differential patterns for incentive subgroups. Participants in the relapse prevention group had high abstinence (>80%; eg, during weeks 7-26 in the modified intention-to-treat analysis, 410 of 456 samples [89.9%] from participants in the bupropion SR group tested negative for cocaine) throughout the trial regardless of whether they were randomized to bupropion SR or placebo. Participants in the abstinence initiation group had better outcomes with bupropion SR than placebo throughout the trial (mean [SD] total number of samples testing negative for cocaine, 30.3 [21.6] samples for bupropion SR vs 17.1 [14.9] samples for placebo; P =.05) and more participants receiving bupropion SR than placebo were abstinent at the end of the study (20 of 30 participants [66.7%] vs 9 of 30 participants [30.0%]; P =.04). Conclusions and Relevance: In this randomized clinical trial, an overall benefit for bupropion SR vs placebo when combined with a financial abstinence incentive program was not observed. Results among incentive subgroups suggest that continued evaluation of medications, including bupropion SR, for stimulant treatment using a tailored approach that factors early abstinence into study design and interpretation may be needed. Trial Registration: ClinicalTrials.gov Identifier: NCT02111798.