Risk of fentanyl overdose among clients of the Sydney Medically Supervised Injecting Centre

Fentanyl is a powerful analgesic, the prescription of which has increased markedly in recent years. The emergence of the drug at the Sydney Medically Supervised Injecting Centre (MSIC) warranted a retrospective clinical audit to assess the risk of fentanyl overdose in comparison with other opioids, in the context of a drug consumption room.Heroin, fentanyl or other prescription opioids (PO) injections resulting in overdose were audited (September 1, 2012 and August 31, 2015). Rates of overdose per 1000 injections and relative risks (RR) of overdose were calculated.In the audit period 189,203 injections by 4177 individuals occurred, with fentanyl injections increasing by 1000%, heroin injections increasing by 70% and, inversely, a sharp decline in other PO injections. Fentanyl injections had approximately four and half times the risk of resulting in overdose than heroin or other PO injections combined (RR=4.6); and, had two times the risk of heroin injections, and eight times the risk of resulting in overdose than other PO injections (RR=2.2 and RR=7.9).Findings from a drug consumption room, such as the Sydney MSIC can effectively inform harm reduction services and emergency services of the increased use of, and therefore risk of, fentanyl overdose relative to other opioids. The dynamic nature of drug markets mean that services such as MSIC are uniquely placed to provide not only real-time data on drug use trends, but also safer injecting advice to those engaging in new practices.