The impact of OxyContin reformulation at the Sydney Medically Supervised Injecting Centre: Pros and cons

Abstract

Abstract Background Oxycodone is implicated in a large number of overdose deaths, many involving intravenous administration of preparations designed for oral administration. International responses have included education strategies, regulatory changes, and tamper-resistant preparations to discourage injecting. Reformulated OxyContin ® was introduced in Australia in April 2014 and this study examines its impact on service utilisation, defined as visits to inject drugs at the Sydney Medically Supervised Injecting Centre (MSIC) and opioid overdoses at the MSIC. Methods Data from February 2007 to February 2016 are presented for drug type injected and onsite opioid overdose. The reformulated OxyContin ® effect was modelled using an interrupted time series approach. Results Client visits declined >1000 per month, or 18%, following reformulation, largely explained by a reduction in visits to inject oxycodone, partially offset by increased morphine or fentanyl injections. Despite this significant reduction in visits, there was no corresponding decrease in the number of overdoses managed, explained somewhat by a partial displacement from oxycodone to other opioids. Stable overdose numbers within the context of decreased visit numbers were consistent with increases in heroin and morphine overdose, with an extra 22 heroin and 12 morphine overdoses on average per month. This increase was offset by the decrease of 17 OxyContin ® , overdoses per month. Conclusions This study replicates the trend towards substitution of OxyContin ® with other opioids following the introduction of reformulated OxyContin ® in Australia and extends initial findings by showing the rate of overdose per MSIC visit increased following reformulation. These unintended consequences need to be considered when evaluating the success or otherwise of these kinds of changes in product formulation.