Adult Medical Cannabinoid Use and Changes in Prescription Controlled Substance Use

Introduction: Nonopioid-based strategies for managing chronic noncancer pain are needed to help reduce overdose deaths. Although lab studies and population-level data suggest that cannabinoids could provide opioid-sparing effects, among medical cannabis participants they may also impact overdose risk by modifying other controlled substance use such as sedative hypnotics. However, no study has combined observational data at the individual level to empirically address interactions between the use of cannabinoids and prescribed controlled substances. Methods: Electronic health records, including prescription drug monitoring program data, from a large multisite medical cannabis program in New York State were abstracted for all participants with noncancer pain and recently prescribed noncannabinoid controlled substances who completed a new intake visit from April 15, 2018-April 14, 2019 and who remained actively in treatment for >180 days. Participants were partitioned into two samples: those with recent opioid use and those with active opioid use and co-use of sedative hypnotics. A patient-month level analysis assessed total average equivalent milligrams by class of drug (i.e., cannabinoid distinguishing tetrahydrocannabinol [THC] vs. cannabidiol [CBD], opioids, and sedative-hypnotics) received as a time-varying outcome measure across each 30-day "month" period postintake for at least 6 months for all participants. Results: Sample 1 of 285 opioid users were 61.1 years of age (±13.5), 57.5% female, and using an average of 49.7 (±98.5) morphine equivalents daily at intake. Unadjusted analyses found a modest decline in morphine equivalents to 43.9 mg (±94.1 mg) from 49.7 (±98.5) in month 1 (p=0.047) while receiving relatively low doses of THC (2.93 mg/day) and CBD (2.15 mg/day). Sample 2 of 95 opioid and sedative-hypnotic users were 60.9 years of age (±13.1), 63.2% female, and using an average of 86.6 (±136.2) morphine equivalents daily, and an average of 4.3 (±5.6) lorazepam equivalents. Unadjusted analyses did not find significant changes in either morphine equivalents (p=0.81) or lorazepam equivalents (p=0.980), and patients similarly received relatively low doses of THC (2.32 mg/day) and CBD (2.24 mg/day). Conclusions: Findings demonstrated minimal to no change in either opioids or sedative hypnotics over the 6 months of medical cannabis use but may be limited by low retention rates, external generalizability, and an inability to account for nonprescribed substance use.