Medical Marijuana Tied to Drop in Opioid Overdose Deaths

States with medical marijuana laws had nearly 25 percent lower opioid overdose death rate

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Prescriptions for opioid painkillers have nearly doubled over the past decade. At the same time, opioid overdose deaths have risen. Could the availability of alternative pain treatments, such as medical marijuana, change those overdose rates?

Researchers recently found that states with medical marijuana laws had lower rates of death from opioid overdoses than states without such laws.

These researchers did not find that medical marijuana laws caused decreases in overdose deaths but that these laws were associated with the decrease.

"Ask a pain specialist about alternative treatments that might work for you."

According to Marcus A. Bachhuber, MD, of the Center for Health Equity Research and Promotion at the Philadelphia Veterans Affairs Medical Center, and colleagues, there is limited evidence on the pain-relieving abilities of marijuana (also known as cannabis). However, the drug may offer relief for some patients, the researchers wrote.

The researchers added that patients already receiving opioid painkillers who start medical marijuana treatment might be able to lower their painkiller dose, which in turn could lower their risk of overdose.

For their study, Dr. Bachhuber and team compared opioid overdose deaths in states with and without medical marijuana laws from 1999 to 2010.

Before 1999, the only three states with medical marijuana laws were California, Oregon and Washington. By 2010, 10 more states added such laws. These states included Alaska, Colorado, Hawaii, Maine, Michigan, Montana, Nevada, New Mexico, Rhode Island and Vermont.

Dr. Bachhuber and colleagues found that states with medical marijuana laws had a 24.8 percent lower average rate of death from opioid overdoses each year compared to states without medical marijuana laws.

Furthermore, it appeared that the association between medical marijuana laws and opioid overdose deaths strengthened over time. In the first year after implementing medical marijuana laws, states had a nearly 20 percent drop of opioid overdose deaths. By the sixth year of implementing these laws, such deaths were down by an average of 33.3 percent.

"If medical marijuana laws afford a protective effect, it is not clear why," wrote Marie J. Hayes, PhD, and Mark S. Brown, MD, both from Eastern Maine Medical Center in Bangor, in a separate commentary on this research.

These commentators noted that one reason it's hard to support the proposal that medical marijuana protects against overdose is that medical marijuana laws differ so greatly among states.

This research did not establish a cause-and-effect relationship between medical marijuana laws and opioid overdose deaths. However, according to Drs. Hayes and Brown, the role that medical marijuana may play in reducing opioid-related deaths "is a fruitful area for future work."

This study and accompanying commentary were published Aug. 25 in JAMA Internal Medicine. The study was funded in part by grants from the National Institutes of Health. One of the study's authors, Dr. Chinazo O. Cunningham, is married to a recent employee of Pfizer and current employee of Quest Diagnostics.

Review Date: 
August 25, 2014
Last Updated:
August 26, 2014