Medical Cannabis and Opioid Receipt Among Adults With Chronic Pain

Importance Medical cannabis is increasingly considered a substitute for prescription opioid medications for chronic pain, driven by the urgent need for opioid alternatives to combat the ongoing epidemic. Objective To determine the association between participation in the New York State (NYS) medical cannabis program and prescription opioid receipt among adults with chronic pain. Design, Setting, and Participants This cohort study used data from the NYS Prescription Monitoring Program (PMP) from September 2018 through July 2023. Adults prescribed opioids for chronic pain who were newly certified for medical cannabis use in NYS were recruited from a large academic medical center and nearby medical cannabis dispensaries in the Bronx, New York. Monthly dispensation of medical cannabis to study participants was monitored for 18 months. Data analyses were performed from February 3, 2025, to July 15, 2025. Exposure Portion of days covered each month by pharmacist report of dispensed medical cannabis. Main Outcomes and Measures Prescription opioid receipt, defined as NYS PMP-reported prescription monthly opioid dispensation (mean daily dose in morphine milliequivalents [MME]), was assessed with marginal structural models adjusted for time-invariant and time-varying confounders, including self-reported unregulated cannabis use. Nonprescribed opioid use was also assessed during the study period. Results Among 204 participants, the mean (SD) age at baseline was 56.8 (12.8) years, and 113 (55.4%) were female. At baseline, participants’ mean (SD) pain severity score was 6.6 (1.8) out of 10, and mean (SD) pain interference score was 6.8 (1.9) out of 10. Baseline mean (SD) daily MME was 73.3 (133.0). During the 18-month follow-up period, participants’ mean (SD) daily MME decreased to 57.4 (127.8). This reduction in mean daily MME was associated with the monthly portion of days covered with medical cannabis; compared with no medical cannabis dispensed, participants dispensed a 30-day supply of medical cannabis were exposed to 3.53 fewer MME per day (β = −3.53; 95% CI, −6.68 to −0.04; P = .03). Conclusions and Relevance In this cohort study, participation in NYS’s medical cannabis program was associated with reduced prescription opioid receipt during 18 months of prospective follow-up, accounting for unregulated cannabis use.