Frequency and severity of non-fatal opioid overdoses among clients attending the Sydney Medically Supervised Injecting Centre.

August 2017
Citation: 
Roxburgh, A., Darke, S., Salmon, A., Dobbins. T. & Jauncey, M. (In press) Frequency and severity of non-fatal opioid overdoses among clients attending the Sydney Medically Supervised Injecting Centre. Drug and Alcohol Dependence.

Pharmaceutical opioid overdose rates have increased in recent years. The current study aimed to compare rates per 1000 injections of non-fatal overdose after heroin or oxycodone injection among clients attending Sydney’s Medically Supervised Injecting Centre.

The authors analysed prospectively collected data from 8382 individual clients who attended the MSIC to inject drugs during the period January 2007 to April 2014. Data was from 2007 onwards as there were no oxycodone overdoses at the MSIC prior to this date. The eligibility criteria to use the service include being at least 18 years of age, and having a history of injecting drug use. Data for non-fatal heroin and pharmaceutical opioid overdose are presented for clients overdosing while attending the MSIC to inject. Severity of overdose was measured using the Glasgow Coma Scale, oxygen saturation levels, and the administration of naloxone.

The analysis found that heroin overdoses occurred at a greater rate than oxycodone overdoses, and had poorer clinical profiles, reflecting greater severity of overdose. One of the consistent factors associated with greater severity of overdose was concomitant use of other central nervous system depressants, indicative that polydrug use is a major risk factor among these opioid overdoses.

Key findings:

  • Heroin overdose (OD) rate was 12.7 ODs per 1000 injections, or approx. 1 in every 80.
  • Oxycodone OD rate was 4.1 ODs per 1000 injections, or approx. 1 in every 250.
  • Heroin injections three times more likely than oxycodone injections to result in OD.
  • Heroin ODs demonstrated a more severe clinical profile than oxycodone ODs.
  • Concurrent use of other depressants a consistent predictive factor for greater severity of OD.

In summary heroin overdoses occurred at a greater rate than oxycodone overdoses, and had poorer clinical profiles, reflecting greater severity of overdose. One of the consistent factors associated with greater severity of overdose was concomitant use of other central nervous system depressants, indicative that polydrug use is a major risk factor among these opioid overdoses