Studies Find Local Cannabis Dispensaries Lead to Drop in Opioid Prescriptions

Cannabis may be a pain-management substitute for people experiencing chronic or acute pain from conditions like cancer, according to new research co-authored by a University of Maryland researcher.

The results are reported in several articles, including ones recently published in JAMA Health Forum focusing on patients with cancer diagnoses, another in the journal Cannabis on the impact of recreational-use cannabis stores, and a forthcoming study in the American Journal of Health Economics about medical-use dispensaries.

The first study, which included as co-author UMD Assistant Professor Shelby Steuart in the School of Public Health’s Department of Health Policy and Management, showed that legalizing the sale and use of medical marijuana—and particularly opening dispensaries to make the drug available—led to fewer opioid prescriptions for cancer patients managing pain.

The forthcoming study, meanwhile, shows that on average, the rate of a broader category of patients receiving opioid prescriptions fell by 16% in states that had legalized medical cannabis. Those results were similar to those in the Cannabis paper led by Steuart that studied areas that allow recreational sales of the drug. (The study was based at the University of Georgia, where Steuart received her Ph.D.)

These decreases were seen across sexes, age groups, and different races and ethnicities, and the researchers found medical and recreational cannabis dispensary openings were associated with significant reductions in all opioid outcomes.

“We’ve written several papers that show cannabis can be a useful pain medicine, reduce nausea and improve sleep and mood,” Steuart said. “Even for patients with some of the worst pain, such as cancer, we have found that cannabis can be an alternative to opioids.”

Pain management professionals are increasingly using cannabis as part of a suite of treatments to not necessarily replace opioids entirely, but to reduce their use—both increasing patient comfort and minimizing the risks of the drugs, including addiction and overdose, she said.

To date, 39 states (including Maryland) and Washington, D.C., have legalized medical cannabis for these patients and others with qualifying conditions. Almost half of all states and D.C. have also legalized recreational cannabis.

Cannabis legalization has a role to play in mitigating the opioid epidemic, said Felipe Lozano-Rojas, lead author of the forthcoming study and an assistant professor in the University of Georgia  School of Public and International Affairs.

“The opioid epidemic is ongoing. Moving away from opiates and toward cannabis seems to be a safer way of managing chronic and acute pain after discussing with the physician in charge of the case,” he said. “That being said, this is not a free-for-all. These findings do not mean that everyone experiencing any pain should use cannabis.”

Prescriptions for non-steroidal anti-inflammatory drugs, like ibuprofen and aspirin, slightly increased during the same time period, suggesting a move toward non-opioid pain management strategies.

The series of studies relied on data from claims of millions of commercially insured patients, with approximately 15 million to 20 million enrollees per year from 2007 to 2020. They address concerns about previous studies that compared states that had legalized cannabis to those that had not. Because of differences in timing, populations and other factors, these comparisons can’t always draw causal conclusions. 

As a group, the studies are among the first to test the relationship between legalized cannabis and opioid use that employ methods that can plausibly support causation.

This article is based on a news release from the University of Georgia.