Preferred pharmaceutical-grade opioids to reduce the use of unregulated opioids: A cross-sectional analysis among people who use unregulated opioids in Vancouver, Canada

Objectives: Many people who use drugs in the United States and Canada continue to access the contaminated unregulated drug supply, resulting in the ever-escalating overdose epidemic. In Canada, even in areas where healthcare providers are authorized to prescribe alternatives to the unregulated supply (e.g., prescribed safer supply), availability and accessibility are low. We sought to characterize the needs of people who use unregulated opioids in Vancouver, Canada by asking them whether access to any pharmaceutical opioids would reduce their use of unregulated opioids, and if so, which pharmaceutical opioids they preferred. Methods: We analyzed data from participants who self-reported using unregulated opioids in three Vancouverbased prospective cohort studies between 2021 and 2022. We employed multivariable logistic regression to identify factors associated with reporting a preferred pharmaceutical opioid to reduce unregulated opioid use. Results: Of 681 eligible participants, 504 (74.0 %) identified a preferred pharmaceutical opioid to reduce unregulated opioid use. The most commonly reported preferred opioids included: diacetylmorphine (42.9 %), fentanyl patches (11.1 %), and fentanyl powder (10.5 %). Overall, 5.6 % of participants who identified diacetylmorphine, 12.5 % of participants who identified fentanyl patches, and no participants who identified fentanyl powder as their preferred opioids reported receiving prescriptions of them. In multivariable analysis, exposure to benzodiazepines through unregulated drug use (adjusted odds ratio [AOR] = 2.57; 95 % confidence interval [CI] = 1.69-3.90), and receipt of prescribed safer supply of opioids without opioid agonist therapy (OAT; AOR = 2.66; 95% CI = 1.12-6.36) within the past six months were significantly associated with reporting a preferred pharmaceutical opioid. Conclusion: Three-quarters of participants reported that receiving prescribed pharmaceutical opioids of their preference could reduce their use of unregulated opioids; however, the proportions of those actually being prescribed their preferred opioids were very low. Further, these participants were also more likely to report exposure to benzodiazepine-adulterated drugs. Our findings provide important implications for future safer supply programs.