Bottom Line: States that implemented medical marijuana laws appear to have lower annual opioid analgesic overdoses death rates (both from prescription pain killers and illicit drugs such as heroin) than states without such laws although the reason why is not clear.
How the Study Was Conducted: The authors examined the implementation of state medical marijuana laws and opioid analgesic overdose deaths in the United States between 1999 and 2010. Three states had medical marijuana laws prior to 1999, 10 states implemented laws between 1999 and 2010 and nine states had laws that went into effect after 2010, which was beyond the study period. The authors also considered New Jersey's law effective after the study period because it took effect in the last quarter of 2010. The authors analyzed state laws and death-certificate data.
Discussion: "In summary, although we found a lower mean annual rate of opioid analgesic mortality in states with medical cannabis laws, a direct causal link cannot be established. ... If the relationship between medical cannabis laws and opioid analgesic overdose mortality is substantiated in further work, enactment of laws to allow for use of medical cannabis may be advocated as part of a comprehensive package of policies to reduce the population risk of opioid analgesics."
Editor's Note: An author made a conflict of interest disclosure. This work was funded by National Institutes of Health grants and the Center for AIDS Research at the Albert Einstein College of Medicine and Montefiore Medical Center. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
In a related commentary, Marie J. Hayes, Ph.D., of the University of Maine, Orno, and Mark S. Brown, M.D., of the Eastern Maine Medical Center, Bangor, write: "If medical marijuana laws afford a protective effect, it is not clear why. If the decline in opioid analgesic-related overdose deaths is explained, as claimed by the authors, by increased access to medical marijuana as an adjuvant medication for patients taking prescription opioids, does this mean that marijuana provides improved pain control that decreases opioid dosing to safer levels?"
"The potential protective role of medical marijuana in opioid analgesic-associated mortality and its implication for public policy is a fruitful area for future work," they conclude.
Media Advisory: To contact author Marcus A. Bachhuber, M.D., call Katie Delach at 215-349-5964 or email katie.delach@uphs.upenn.edu. To contact commentary author Marie J. Hayes, Ph.D., call Margaret Nagle at 207-581-3745 or email nagle@maine.edu.
To place an electronic embedded link to this study in your story: Links for this study and commentary will be live at the embargo time: http://archinte.jamanetwork.com/article.aspx?doi=10.1001/jamainternmed.2014.4005 and http://archinte.jamanetwork.com/article.aspx?doi=10.1001/jamainternmed.2014.2716.