Association of route of drug administration with self-reported non-fatal overdose: A cohort study of Baltimore City adults who have injected drugs.

backgroundThe COVID-19 pandemic was associated with a shift among people who use drugs away from injecting opioids and toward other routes of administration. We examined if specific routes of heroin administration were associated with overdose risk.

methodsALIVE is a cohort of adults from Baltimore, MD who have a history of injecting drugs. At twice-annual visits, participants self-reported past-six-month drug use and related information. At visits when participants reported heroin use, we estimated the association of self-reported route of heroin administration (injecting, smoking, nasal inhalation ["snorting"], injecting & smoking, injecting & nasal inhalation, smoking & nasal inhalation, all three) with non-fatal overdose using conditional logistic regression.

resultsAt visits when heroin was reported (1121 participants, 4396 study visits, 88 % age 40-79, 33 % female, 77 % Black) using heroin by all three routes of administration was associated with higher overdose odds than using injecting only (aOR 2.37, 95 % CI 1.25-4.47), nasal inhalation only (aOR 2.87, 95 % CI 1.47-5.63), and injecting and smoking (aOR 4.22, 95 % CI 1.01-17.68); injecting and nasal inhalation was associated with overdose as compared to nasal inhalation alone (aOR 1.78, 95 % 1.12-2.83).

conclusionWe found no evidence any individual route of administration was associated with higher heroin overdose risk; instead, use of a single route tended to be associated with lower overdose odds than use of multiple routes. Harm reduction programs that provide sterilized tools for drug administration may empower people who use drugs to avoid overdose risk.