Estimating the proportion of patients who transition to long-term opioid use following oxycodone initiation in the emergency department

To report the number of patients discharged from ED with oxycodone immediate release (IR) over 12 months and estimate the proportion who potentially transition to long-term opioid use and subsequent injectable heroin use.

Retrospective observational data were collected from a major tertiary-referral metropolitan ED in Melbourne, Australia, describing the number of patients discharged with an oxycodone IR prescription and proportion of discharge scripts filled. These data were projected against published data reporting trends on patients' trajectory to long-term opioid use, to subsequently estimate the proportion of patients from this cohort that may transition to injectable heroin use.

Of the 87 551 ED presentations in 2018, there were 4843 prescriptions written for oxycodone IR for 4102 different patients. An estimated 279 patients may become long-term opioid users following initial ED presentation. Of these 279 patients, 1.4 patients may potentially transition to injectable heroin use.

Modelling opioid use behaviour in an ED population demonstrated the potential development of unintentional long-term opioid use, and associated harms. Prospective study is required to fully understand trajectories of patients dispensed outpatient therapy from Australian EDs.