Medical marijuana shows early promise to minimize opioid use and potential abuse, but the preliminary research that more studies need to validate. And suggests a systematic review of published studies to be discussed at the 2019 Annual Meeting of ANESTHESIOLOGY ®. Nonetheless, much more rigorous scientific research needs to be done to establish if medical marijuana really has pain relief effects that can relieve chronic pain and mitigate potential risks.
The analysis focused on seven studies, five of which found medical marijuana can be correlated with benefits such as reduced rates of misuse of opioids, decreased use of opioids, improved quality of life, and improved pain control.
The various findings from the five studies that showed a positive benefit included a 29% reduction in opioid overdoses in states with medical marijuana and a 44% to 64% reduction in opioid use among chronic pain patients. The two other studies found no evidence of reduced opioid use overall.
“Overall the results suggest medical marijuana may provide some benefit in mitigating opioid misuse, but the studies were not randomized controlled trials comparing marijuana to a placebo, which is what we need to determine a true benefit,”said Mario Moric, MS, lead author of the study and a biostatistician at Rush University Medical Center, Chicago.
“Long-term effects of medical marijuana are not known and haven’t been studied yet. Early clinical evidence suggests that marijuana might have detrimental effects on the brain,” said Asokumar Buvanendran, M.D., co-author of the study, chair of the American Society of Anesthesiologists (ASA) Committee on Pain Medicine and vice-chair of research at Rush University Medical Center.
The researchers determined the effect of the combined studies was .59, meaning the benefits of medical marijuana were found to be weak to moderate overall, but significant.
The known side effects of marijuana can range from sleepiness to liver damage. Short-term opioids can be useful for easing the pain when managed safely and the risks are minimized, but longer use needs to be weighed for risk vs. benefit.
Currently, 33 states and Washington, D.C., have legalized medical marijuana, but all set their own regulations, which vary. Also, the lack of oversight and inconsistent regulation means ingredients can differ and may include pesticides and other impurities.
More than 11 million Americans misuse opioids, more than 2 million have an opioid abuse disorder and an estimated 130 people die of an opioid overdose every day, according to the U.S. Department of Health and Human Services. More than 20% of Americans suffer from chronic pain, according to the Centers for Disease Control and Prevention.
“While we await better research on marijuana, pain specialists such as physician anesthesiologists can offer many non-opioid medications and other alternatives to treat chronic pain such as injections, nerve blocks, physical therapy, and spinal cord stimulation,” said Dr. Buvanendran.
The ASA supports more rigorous studies on marijuana and recently endorsed two bills that seek to expand research: H.R. 601, the Medical Cannabis Research Act of 2019 and S. 2032, the Cannabidiol and Marihuana Research Expansion Act.