REVIEW OF: Shulman M et al, Drug Alcohol Depend 2025;268:112550

STUDY TYPE: Secondary analysis of an RCT

Cannabis use is common among patients with opioid use disorder (OUD), but could the choice of medication for OUD influence cannabis use during recovery? A secondary analysis of the X:BOT trial offers some insight. That trial found that buprenorphine-naloxone (buprenorphine) and extended-release naltrexone (injectable naltrexone) were equally safe and effective in treating OUD once initiated (Lee JD et al, Lancet 2018;391(10118):309–318).

The trial randomized 570 adults with OUD to buprenorphine or injectable naltrexone and followed them for 24 weeks. Participants had weekly assessments including self-reported cannabis use confirmed by urine testing. Researchers used mixed-effects logistic regression and mediation models to determine whether medication type influenced cannabis use, and whether cannabis use affected the likelihood of participants returning to opioid use.

At baseline, ~40% of participants reported using cannabis. Those treated with buprenorphine were ~40% less likely to use cannabis than those on injectable naltrexone (p = 0.0499), possibly because buprenorphine’s partial agonist activity dampens anxiety and craving, reducing the urge to use cannabis. Analyses revealed that cannabis use did not mediate opioid outcomes, nor did opioid use affect cannabis use, suggesting that buprenorphine’s effect on cannabis use was independent of its effects on opioids.

CARLAT TAKE
Buprenorphine was linked to reduced cannabis use compared to injectable naltrexone—a secondary finding, but a clinically meaningful one. Clinicians treating OUD patients who also use cannabis may want to factor this in, particularly given that buprenorphine is also easier to initiate than injectable naltrexone.