The legalization of marijuana in Canada preceded a “significant decrease” in the volume of opioid prescribed to patients enrolled on both public and private health insurance plans. This is evident from data published in the journal Applied Health Economics and Health Policy.
A team of investigators affiliated with the University of Toronto evaluated the volume of opioids prescribed and the amount spent on opioids in the months immediately prior to and immediately after adult marijuana sales were legalized. The researchers obtained loss data for more than 80 percent of all opioids prescribed in Canada during the study period (January 2016 to June 2019).
In line with the results of other environmental studies, the researchers concluded: “The legalization of cannabis coincided with a significant decrease in the levels of opioids prescribed in Canada.”
The authors concluded: “The results of this 42-month time series analysis showed a steady and significantly consistent decrease in the mean and mean MED [morphine equivalent dose] per claim for public payer drug plans. However, when comparing the pre-legalization and post-legalization periods, the decrease in mean MED per application over the post-legalization period was about 5.4 times higher (22.3 versus 4.1 mg per application). Additionally, prior to October 2018, the monthly reduction in opioid spending by public payers averaged $ 95,000 per month [when adult-use sales were legalized] compared to Can267,000 per month after cannabis legalization. Similar results were seen with private drug plans. … The results of this study add to the growing evidence that easier access to cannabis for patients in pain can reduce opioid use and partially offset spending on public and private drug plans. “
The abstract of the study, “Opioid Prescribing in Canada After Cannabis Legalization: A Clinical and Economic Time Series Analysis” appears online here. For more information, see the NORML Fact Sheet “Relationship Between Marijuana and Opioids”