High risk injecting behaviour among people who inject pharmaceutical opioids in Australia.

Background: Use of opioid analgesic medicines has doubled globally over the past decade, with a concomitant increase in prevalence of injection of pharmaceutical opioids (PO), including in Australia. This study investigates types of PO injected, methods used to prepare PO for injection and correlates of recent (last 6 months) PO injection among a large national sample of people who inject drugs (PWID).

Methods: The Australian NSP Survey (ANSPS), conducted annually at ∼50 NSP services across Australia, consists of a brief self-administered questionnaire and provision of a capillary dried blood spot for HIV and hepatitis C antibody testing. Data from 2014 were used to conduct univariable and multivariable logistic regression analysis to determine factors independently associated with recent injection of PO.

Results: Among 1488 ANSPS respondents who were identified as opioid injectors, 57% (n=848) reported injection of PO in the previous six months. The majority of PO injectors (85%) reported filtering PO prior to injection, although use of efficacious wheel filters was relatively rare (11%). Correlates of POs injection included daily injection (AOR=1.65, 95% CI 1.31-2.08), receptive sharing of syringes (AOR=2.00, 95% CI 1.43-2.78), receptive sharing of drug preparation equipment (AOR=1.55, 95% CI 1.19-2.01), drug overdose in the previous year (AOR=1.81, 95% CI 1.36-2.42) and residence in inner regional (AOR=3.27, 95% CI 2.21-5.23) or outer regional/remote (AOR=5.50, 95% CI 3.42-8.84) areas of Australia.

Conclusion: PO injection is geographically widespread among Australian PWID and takes place in the context of poly-drug use. People who inject POs are at high risk of overdose, injection related injury and disease and blood borne viral infections. Harm reduction services that target this group, including in non-urban areas, should deliver health education regarding PO-specific overdose risks, the requirement to adequately filter PO before injection and to ensure that both naloxone and specialist pill filters are readily accessible.