Twenty-nine states and the District of Columbia have passed medical cannabis laws (MCL) permitting cannabis as a medical treatment for indications associated with chronic pain. Past studies have found an association between MCLs and reduced opioid prescribing and opioid-related harms. This analysis sought to identify changes in state-level opioid dispensing following MCL implementation among patients using Medicare Part D benefits in calendar years 2010–2015. The study examined two specific types of MCLs: those permitting patients to cultivate their own cannabis at home, and those in which a dispensary has actually been opened.
- Implementation of home cultivation was associated with a 7% reduction in daily opioid doses.
- Dispensary opening was associated with a 14% reduction in daily opioid doses.
Comments: These data further our understanding of the association between MCL and opioid prescribing by considering two specifics of MCL implementation: permitting home cultivation and opening of dispensaries. Causal inference from the observed association is limited by lack of data on uptake of medical cannabis and absence of controlling for myriad other efforts to address opioid prescribing over the same timeframe.
Marc R. Larochelle, MD, MPH
Reference: Bradford AC, Bradford WD, Abraham A, Bagwell Adams G. Association between US state medical cannabis laws and opioid prescribing in the Medicare Part D population. JAMA Intern Med. 2018; 178(5):667–673.