Medical Cannabis and Opioid Prescription Discontinuation Among Chronic Pain Patients on Long-term Opioid Therapy

OBJECTIVES: To examine the association between medical cannabis use and discontinuation of prescription opioids among patients with chronic pain receiving long-term opioid therapy, overall, by time, and opioid dosage. METHODS: We used New York State Medical Cannabis and Prescription Monitoring Program data (2017-2019), including 8358 patients on long-term opioid therapy, who also received medical cannabis for chronic pain. Patients were followed for 90 days and were classified as "medical cannabis patients" if they received medical cannabis for >30 days and "no-medical cannabis" if they received 30 days or less. Prescription opioid discontinuation was defined as a break in opioid prescriptions of 45 days or longer. Multivariate time-to-event models [stratified by baseline morphine milligram equivalent (MME)] were used. RESULTS: The medical cannabis group included 4892 patients, and the no-medical cannabis group included 3466 patients. Overall, opioid prescription discontinuation was 2 times higher among those using medical cannabis (15.5%), compared with the no-medical cannabis group (7.6%) (P<0.001). Among patients with a baseline MME <50, opioid discontinuation was faster in the first 30 days of the follow-up period, with an adjusted hazard ratio (aHR) of 2.87 (95% CI: 2.22-3.70) and reduced to 1.81 (95% CI: 1.43-2.29) after 30 days. For patients with a baseline MME 50-<90, the aHR was 3.13 (95% CI: 2.09-4.68) throughout follow-up. No significant associations were found among patients with a baseline MME ≥90. CONCLUSIONS: Patients receiving medical cannabis were more likely to discontinue prescription opioids, which may lower morbidity and mortality risks associated with long-term opioid therapy or abrupt discontinuation of opioid prescriptions.