Trends in opioid initiation among people who use opioids in three US cities

Introduction and Aims: The increased availability of prescription opioids (PO) and non-medical prescription opioids (NMPO) has fundamentally altered drug markets and typical trajectories from initiation to high-risk use among people who use opioids (PWUO). This multi-site study explores trends in opioid initiation in three US cities and associations with sociodemographic factors, current drug use and overdose risk. Design and Methods: We analysed survey data from a cross-sectional study of PWUO in Baltimore, Maryland (n = 173), Boston, Massachusetts (n = 80) and Providence, Rhode Island (n = 75). Age of first exposure to PO, NMPO and heroin was used to calculate opioid of initiation, and multinomial regression was employed to explore correlates of initiating with each. Results: Thirty-three percent of PWUO initiated with heroin, 24% with PO, 18% with NMPO and 24% with multiple opioids in their first year of use. We observed a reduction in heroin initiation and gradual replacement with PO/NMPO over time. Women were more likely to initiate with NMPO [relative risk ratio (RRR) 2.4; 95% confidence interval (CI) 1.1, 5.0], PO (RRR 2.2, 95% CI 1.1, 4.4) or multiple opioids (RRR 2.1, 95% CI 1.1, 4.2), than heroin. PWUO initiating with NMPO had significantly higher current benzodiazepine use, relative to those initiating with heroin (RRR 3.2, 95% CI 1.4, 7.4), and a high prevalence of current fentanyl use (30%). Discussion and Conclusions: Our study highlights women and PWUO initiating with NMPO as key risk groups amid the changing landscape of opioid use and overdose, and discusses implications for targeted prevention and treatment.