OBJECTIVE: We describe analytically confirmed opioid-related presentations to emergency departments (EDs) in Australia.

METHODS: Presentations with analytically confirmed opioid exposure, between January 2021 and December 2024, were identified from the Emerging Drugs Network of Australia (EDNA) Clinical Registry. Demographic data, clinical features, outcomes, naloxone dosing, and analytical toxicology results were extracted.

RESULTS: Opioids were detected in 793 ED presentations. The majority were male (568, 71.6%) with a median age of 40 years (Q1-Q3: 30-48 years). Patients were unwell (Australasian Triage Score 1 or 2 = 700, 88.3%). Suicidal intent was noted in 55 (6.9%) presentations. Mono-opioid detections occurred in 550 (69.4%) presentations, most frequently heroin exposures (162, 29.5%). Novel opioids including nitazenes and U-Class synthetic opioids were uncommon (21, 2.6%). Illicit co-detections were common (547, 69.0%) especially with methylamphetamine (512, 64.6%), gamma-hydroxybutyrate (108, 13.6%), and diazepam (341, 43%). Naloxone was used in 498 (62.8%) presentations: median dose 400 μg (IQR: 200-600 μg). There was no difference in median naloxone dose for heroin (median 320 μg) and novel opioids (median 500 μg, p = 0.25). Intubation was more likely to occur in patients with novel opioids compared to heroin (8/21, 26/162, p = 0.020).

CONCLUSIONS: Heroin was the most common analytically confirmed illicit opioid detected among opioid-related ED presentations. Novel opioids were uncommon with no difference in median naloxone dose used. There were higher intubation rates for novel opioids. Polydrug exposure is common, complicating the clinical picture. Increased awareness of the national Take Home Naloxone program, particularly by emergency physicians, is a key element of harm reduction.