Prescription-, illicit-, and self-harm opioid overdose cases treated in hospital

Objective: Research suggests unintentional overdose on prescription drugs and intentional self-harm cases differ fundamentally from unintentional illicit drug overdoses, but there are few data on opioid overdose per se. Method: We analyzed consecutive opioid overdose patients age 13 and over (N = 435) treated by a toxicology consult service to compare three poisoning groups: unintentional illicit drug (illicit, n = 128), unintentional prescription drug (prescription, n = 217), and intentional self-harm (self-harm, n = 90). The groups were compared on key characteristics of the poisoning events (severity, co-ingestion of non-opioid) and the hospital-based treatments required to manage the poisonings (use of antidote, provision of pharmacological support). Logistic regressions yielded incident rate ratios (IRRs) and 95% confidence intervals (CI) adjusted for age and sex. Results: Compared to the illicit group, the prescription group was more likely to co-ingest a non-opioid drug (IRR [95% CI] = 1.594 [1.077, 2.358], p = .020. Compared to illicit cases, self-harm cases were more likely to co-ingest a non-opioid drug (IRR = 3.181 [1.620, 6.245], p = .001) and had a lower poisoning severity score (IRR = 0.750 [0.564, 0.997], p = .048). There were no statistically significant differences between the self-harm and prescription groups. Conclusions: The similarities between the self-harm and prescription poisoning groups suggest that they may benefit from common interventions including appropriate restriction on prescription of opioids and other medications that may be misused (e.g., sedative-hypnotic/ muscle relaxants). The characteristics of the illicit poisoning group (use of heroin; more severe overdose events) suggest the need for initiation of intensive substance use treatment interventions during hospitalization.