International Society for the Study of Drug Policy (ISSDP) 2024

CANNABIS USE TO MANAGE OPIOID AND STIMULANT CRAVINGS AMONG PEOPLE WHO USE UNREGULATED DRUGS DURING IN THE FENTANYL ERA

Background: Accumulating evidence documents that cannabis is employed as a harm reduction strategy among some people who use unregulated drugs (PWUD) yet the impact of overdose risk has not been investigated. We sought to investigate the association between cannabis use to manage cravings for drugs and self-reported changes in substance use among structurally-marginalized PWUD. We also analyzed longitudinal associations between cannabis use and risk factors for overdose.

Methods: Interview and urinalysis data were systematically collected from PWUD in three prospective cohort studies of PWUD in Vancouver, Canada. We analyzed the association between cannabis use and overdose risk (non-fatal overdose and fentanyl exposure) using multivariable generalized estimating equations. The analysis of cannabis use to manage drug cravings was collected from a subsample of these cohorts who completed a supplementary cannabis questionnaire and binary logistic regression was used to analyze the association between cannabis use to manage drug cravings and self-reported changes in unregulated drug use.

Results: We enrolled 3,937 PWUD into the present study between December 2005 to November 2023. Daily cannabis use was associated with decreased odds on non-fatal overdose (Adjusted Odds Ratio [AOR]=0.90, 95% confidence interval [CI]: 0.82, 0.98) and recent exposure to fentanyl (AOR=0.48, 95% CI: 0.43, 0.54) as measured by urinalysis. Cannabis use to manage opioid and stimulant cravings was common (opioids: 44%, stimulants: 45%) and was significantly associated with decreased odds of opioid (AOR=0.44, 95% CI: 0.23, 0.86) and stimulant use (AOR=0.24, 95% CI: 0.10, 0.56), respectively.

Conclusions: These findings indicate that cannabis use to manage cravings for other unregulated drugs is a prevalent motivation among PWUD and is associated with self-assessed reductions in opioid and stimulant use. Frequent cannabis use was also longitudinally associated with decreased odds of non-fatal overdose and fentanyl exposure. These results suggest that supporting the intentional use of cannabis for harm reduction among people at highest risk of overdose could be a useful intervention to mitigate exposure to the toxic unregulated drug supply.