Medical Marijuana Laws, Dispensaries May Reduce Deaths From Opioid Overdose

Medical marijuana laws that include a “liberal” allowance of the drug to dispensaries may contribute to reducing opioid overdose-related deaths in Medicare Part D and Medicaid beneficiaries, according to a study published in the Journal of Health Economics.¹

Medical marijuana has proven an effective analgesic for a number of conditions that include chronic noncancer pain.²

Several studies examining the effects of state laws that permit the use of medical marijuana have found that their adoption led to reduced numbers of prescriptions for pain medications in Medicare Part D and of opioid-related hospitalizations and deaths.^3-5

“The implication from these studies is that medical marijuana laws enable individuals to substitute marijuana for opiates, particularly opioid analgesics,” stated the study authors, noting that the mechanisms underlying this behavior are not understood.

Seeking to identify the aspects of state medical marijuana laws — heterogeneous from state to state — which may drive patients to switch from opiates to marijuana, the investigators examined the effects of medical marijuana allowances to dispensaries under these laws. Existence of such allowances has been associated with improved patient access to the drug as well as access to more potent marijuana.^6,7 In their analysis of medical marijuana state laws, the investigators studied at the state level, admissions to treat addiction to opioid pain relievers and overdose deaths from prescription opioids, alone or in combination with heroin.

In their analysis, the existence of dispensaries was found to reduce opioid-related death rates by approximately 40% and 20% between 1999 and 2010 and between 1999 and 2013, respectively, “above and beyond the reduction from marijuana laws alone,” which is approximately 5% between 1999 and 2013. Marijuana laws combined with dispensary provisions during that same time period led to a 25% reduction in opioid overdose-related deaths (P <.05). Results were similar when assessing overdose deaths resulting from a combination of heroin and prescription opioids. The presence of dispensaries had a greater impact on overdose deaths resulting from the use of natural and semisynthetic opioids (eg, oxycodone) vs synthetic opioids (eg, fentanyl) or heroin.

No association was found between medical marijuana laws and the rate of treatment admissions for addiction to opioid analgesics. However, the presence of operational dispensaries was found to reduce by 38% the rate of admissions for abuse of prescription opioids and heroin combinations. Neither medical marijuana laws nor dispensaries were found to reduce legal distribution of opioid analgesics, but rather, the opposite was observed for the 1999 to 2010 period, coinciding with the reduction in both overdose deaths and treatment for opioid addiction resulting from marijuana laws.

“This implies that access to medical marijuana through dispensaries must decrease the harm from opioids (overdoses and addiction), but not necessarily the medical use of opioids,” noted the authors. In addition, event studies indicated that full implementation of dispensaries (active and legal) resulted in large reductions in opioid-related deaths, an effect that lasted beyond the adoption period. Both medical marijuana laws of any type and dispensaries led to long-term reductions in treatment admissions for opioid addiction treatment. 

“Our results suggest a potential overlooked positive effect of medical marijuana laws that support meaningful retail sales,” concluded the investigators.

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References

1. Powell D, Pacula RL, Jacobson M. Do medical marijuana laws reduce addictions and deaths related to pain killers? J Health Econ. 2018;58:29-42.
2. Lynch ME, Ware MA. Cannabinoids for the treatment of chronic non-cancer pain: an updated systematic review of randomized controlled trials. J Neuroimmune Pharmacol. 2015;10(2):293-301.
3. Bradford AC, Bradford WD. Medical marijuana laws reduce prescription medication use In Medicare Part D. Health Aff (Millwood). 2016;35(7):1230-1236.
4. Shi Y. Medical marijuana policies and hospitalizations related to marijuana and opioid pain reliever. Drug Alcohol Depend. 2017;173:144-150.
5. 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.
6. Pacula RL, Hunt P, Boustead A. Words can be deceiving: a review of variation among legally effective medical marijuana laws in the United States. J Drug Policy Anal. 2014;7(1):1-19.
7. Sevigny EL, Pacula RL, Heaton P. The effects of medical marijuana laws on potency. Int J Drug Policy. 2014;25(2):308-319.