Opioid poisoning in Newcastle over the last three decades: From heroin to prescription opioids

Opioid-related harm has risen in recent decades, but limited research describes the clinical burden of opioid poisoning to Australian EDs. We aimed to investigate hospital presentations with opioid poisoning over three decades. This is an observational series of prospectively collected data investigating presentations of opioid poisoning to an ED in Newcastle (1990-2021). Type of opioid, naloxone administration, intubation, intensive care unit (ICU) admission, length of stay and death were extracted from the unit's database. There were 4492 presentations in 3574 patients (median age 36, 57.7% female), increasing from an average of 93 presentations annually in the first decade to 199 in the third decade. Deliberate self-poisonings accounted for 3694 presentations (82.2%). Heroin dominated the 1990s, peaking in 1999 before decreasing. Prescription opioids then rose, with codeine (usually in paracetamol combination) predominating until 2018, after which oxycodone presentations exceeded them. Methadone consistently increased from six presentations annually in the first decade to 16 in the last decade. Naloxone was administered in 990 (22.0%) presentations and 266 (5.9%) were intubated, most frequently following methadone and heroin exposures. ICU admissions increased from 5% in 1990 to 16% in 2021. Codeine exposures resulted in less severe effects, whereas methadone had more severe effects overall. The median length of stay was 17 h (interquartile range 9-27 h). There were 28 deaths (0.6%). Opioid presentations increased in number and severity over three decades as the type of opioid changed. Oxycodone is currently the main opioid of concern. Methadone poisoning was the most severe.