The impact of cannabis on non-medical opioid use among individuals receiving pharmacotherapies for opioid use disorder: a systematic review and meta-analysis of longitudinal studies

• Published in: The American journal of drug and alcohol abuse 2024-01, Vol.50 (1), p.12-26
• Main Authors: Costa, Gabriel P A, Nunes, Julio C, Heringer, Daniel L, Anand, Akhil, De Aquino, Joao P
• Format: Article
• Language: English
• Subjects: Analgesics, Opioid - therapeutic use; Buprenorphine; Buprenorphine - therapeutic use; Drug therapy; Efficacy; Humans; Longitudinal Studies; Marijuana; Maximum likelihood method; Meta-analysis; Methadone; Methadone - therapeutic use; Naltrexone; Naltrexone - therapeutic use; Narcotics; Opiate Substitution Treatment - methods; Opioid-Related Disorders - drug therapy; Opioids; Sensitivity analysis; Substance use disorder; Systematic review
• ISSN: 0095-2990; 1097-9891; 1097-9891
• DOI: 10.1080/00952990.2023.2287406

The relationship between cannabis use and the risk of returning to using opioids non-medically during treatment for opioid use disorder (OUD) remains unclear. We sought to quantify the impact of cannabis use on the risk of non-medical opioid use among people receiving pharmacotherapies for OUD. A comprehensive search was performed using multiple databases from March 1 to April 5 of 2023. Eligible studies longitudinally assessed the association between cannabis use and non-medical opioid use among people with OUD receiving treatment with buprenorphine, methadone, or naltrexone. We utilized a random-effects model employing the restricted maximum likelihood method. A sensitivity analysis was conducted to understand potential differences between each OUD treatment modality. A total of 10 studies were included in the final meta-analysis. There were 8,367 participants (38% female). The average follow-up time across these studies was 9.7 months (SD = 3.77), ranging from 4 to 15 months. The pharmacotherapies involved were methadone (76.3%) buprenorphine (21.3%), and naltrexone (2.4%). The pooled odds ratio did not indicate that cannabis use significantly influenced non-medical opioid use (OR: 1.00, 95% CI: 0.97-1.04,  = .98). There is evidence of moderate heterogeneity and publication bias. There was no significant association between cannabis use and non-medical opioid use among patients receiving pharmacotherapies for OUD. These findings neither confirm concerns about cannabis increasing non-medical opioid use during MOUD, nor do they endorse its efficacy in decreasing non-medical opioid use with MOUD. This indicates a need for individualized approaches for cannabis use and challenges the requirement of cannabis abstinence to maintain OUD pharmacotherapies.