States Allowing Medical Marijuana May Have Lower Mortality From Opioid Analgesic Overdose
Although chronic or severe pain is a common indication for medical marijuana in some states, it is not known whether opioid analgesic mortality has decreased in the 23 states that have adopted medical marijuana laws. Researchers compared opioid analgesic overdose mortality rates from 1999 to 2010 between states with and without medical marijuana laws. They developed multivariable regression models with time-varying implementation of medical marijuana laws as the main independent variable and adjusted for state-specific prescription opioid control policies and unemployment rate.
- Age-adjusted opioid analgesic overdose mortality rates increased from 1999 to 2010 in states with and without medical marijuana laws, but were higher in states with such laws.
- In adjusted analyses, opioid analgesic overdose mortality decreased by 25% in states with medical marijuana laws compared with states without laws. Similar results were seen in analyses restricted to outcomes of non-suicide overdose deaths and heroin overdose deaths.
- State-specific analyses did not indicate a significant difference in opioid analgesic overdose mortality before and after implementation of medical marijuana laws.
Comments:
The results of this analysis are very intriguing, but do not demonstrate a causative association. Many opioid analgesic overdoses occur in individuals who are not receiving treatment for pain. Medical marijuana could potentially lead to decreased opioid overdose mortality by serving as an adjuvant analgesic or anxiolytic/intoxicant when taken instead of prescription and non-prescription opioids. Prospective studies are needed to determine the utility of medical marijuana policies in decreasing harm from opioid analgesics.
Kevin L. Kraemer, MD, MSc
Reference:
Bachhuber MA, Saloner B, Cunningham CO, Barry CL. Medical cannabis laws and opioid analgesic overdose mortality in the United States, 1999-2010. JAMA Intern Med. 2014; 174(10):1668–1673.