Trends in varying modes of drug use in opioid toxicity deaths in Ontario from 2017 to 2021.

Abstract

Preliminary data indicate a shift toward inhalation instead of injection in opioid toxicity deaths. Understanding changing modes of drug use is essential to addressing the North American drug toxicity crisis driven primarily by unregulated fentanyl. This study aims to comprehensively characterize this shift across Ontario, Canada. We conducted a population-based repeated cross-sectional study of accidental opioid toxicity deaths in Ontario from July 1, 2017 to June 30, 2021. For each quarter of the study period, the number and percent of deaths by mode of drug use (inhalation only, injection only, both or other) were reported. Descriptive characteristics were reported in the last two years of the study. There were 6687 accidental opioid toxicity deaths in Ontario over the study period, with a 62.1% increase in the quarterly number of deaths observed. The prevalence of deaths where inhalation was the only mode of drug use almost doubled, rising from 22.0% to 43.5%. There was a corresponding 64.4% decrease in opioid toxicity deaths with indication of injection alone (29.0% to 10.3%). This study reveals a shift in mode of drug use toward inhalation that is increasingly contributing to opioid toxicity deaths in Ontario. Understanding the shifts in patterns of opioid use serves to provide essential insights into more effective harm reduction and treatment approaches to address the drug toxicity crisis.