New research suggests that cannabis use by people being treated for opioid addiction might improve outcomes and reduce the chance that participants will still take, and be harmed by, black market fentanyl.
Opioid agonist treatments like methadone or buprenorphine/naloxone are commonly used to support people weaning themselves off unregulated opioid usage. But in this study of 819 study participants in Vancouver's Downtown Eastside, 53 percent were still intentionally or inadvertently using fentanyl, while on a detox program.
The researchers from the British Columbia Centre on Substance Use (BCCSU) and University of British Columbia (UBC) found that those in the study who had urine tests positive for THC (the primary psychoactive component of cannabis) were approximately 10 percent less likely to have fentanyl-positive urine, and so were at lower risk of a fentanyl overdose.
The findings suggest people may be supplementing their treatment through the unregulated drug supply, putting them at risk. The THC in marijuana may effectively reduce the addictive power of opioids, aiding the process of coming off them.
"These new findings suggest that cannabis could have a stabilizing impact for many patients on treatment, while also reducing the risk of overdose," said Dr. Eugenia Socías, a clinician scientist at BCCSU and lead author of the study. "With overdoses continuing to rise...these findings highlight the urgent need for clinical research to evaluate the therapeutic potential of cannabinoids as adjunctive treatment to opioid agonist treatments to address the escalating opioid overdose epidemic."
This adds to previous research from the BCCSU, which found that individuals initiating opioid agonist treatments who reported using cannabis on a daily basis were approximately 21 percent more likely to be retained in treatment at six months than non-cannabis users.
However not all evidence points to a benefit of cannabis in opioid addiction.