Pharmaceutical opioid poisonings in Victoria, Australia: Rates and characteristics of a decade of emergency department presentations among nine pharmaceutical opioids.

BACKGROUND AND

aimsPharmaceutical opioids are a significant contributor to the global 'opioid crisis', yet few studies have comprehensively distinguished between opioid types. We measured whether a range of common pharmaceutical opioids varied in their contribution to the rates and characteristics of harm in a population-wide indicator of non-fatal overdose.

designRetrospective observational study of emergency department (ED) patient care records in the Victorian Emergency Minimum Data set (VEMD), July 2009 to June 2019.

settingVictoria, Australia. CASES: ED presentations for non-fatal overdose related to pharmaceutical opioid use (n = 5403), where the specific pharmaceutical opioid was documented. MEASUREMENTS: We compared harms across the nine individual pharmaceutical opioids most commonly sold, and considered where multiple opioids contributed to the overdose. We calculated supply-adjusted rates of ED presentations using Poisson regression and used multinomial logistic regression to compare demographic and clinical characteristics of presentations among nine distinct pharmaceutical opioids and a 10th category where multiple opioids were documented for the presentation.

findingsThere were wide differences, up to 27-fold, between supply-adjusted rates of overdose. When considering presentations with sole opioids, the highest supply-adjusted overdose rates [per 100 000 oral morphine equivalents (OME); 95% confidence interval (CI)] were for codeine (OME = 0.078, 95% CI = 0.073-0.08) and oxycodone (OME =0.029, 95% CI = 0.027-0.030) and the lowest were for tapentadol (OME = 0.004, 95% CI = 0.003-0.006) and fentanyl (OME = 0.003, 95% CI = 0.002-0.004). These rates appeared related to availability rather than opioid potency. Most (62%) poisonings involved females. Codeine, oxycodone and tramadol were associated with younger presentations (respectively, 59.5%, 41.7% and 49.8% of presentations were 12-34 years old), and intentional self-harm (respectively 65.2%, 50.6%, and 52.8% of presentations). Relative to morphine, fentanyl [ 0.32 relative risk ratio (RRR)] and methadone ( 0.58 RRR) presentations were less likely to be coded as self-harm. Relative to morphine-buprenorphine, codeine, oxycodone and tramadol presentations were significantly more likely to be associated with the less urgent triage categories (respectively 2.18, 1.80, 1.52, 1.65 RRR).

conclusionsIn Victoria, Australia, rates and characteristics of emergency department presentations for pharmaceutical opioids show distinct variations by opioid type.