Naloxone cascade of care among people who regularly inject drugs in Australia, 2020-2022

Abstract

Background: Examining take-home naloxone (THN) uptake using a 'cascade of care' framework could help identify targets for increasing THN training and carriage among people who may witness or experience opioid overdose. We describe the THN cascade and factors associated with engagement among people who inject drugs.

Methods: People aged ≥18 years in Australia who inject drugs were interviewed from 2020 to 2022, reporting lifetime THN awareness and acquisition and past-month carriage. We examined factors associated with engagement using multivariable logistic regression.

Results: Of 2,149 participants (64 % men, mean age 44.5), 85 % had heard of naloxone, of whom 76 % were aware of THN programs. Of these, 72 % had ever participated in THN training/brief education, 92 % of whom had acquired THN. Of those who had ever acquired THN and reported past-month opioid use, 63 % always/often carried THN when using opioids. Past six-month opioid agonist treatment (OAT) (adjusted odds ratio [AOR] 2.55; 95 %CI 1.91-3.42) and ≥daily injecting (1.32; 1.01-1.73) were associated with awareness. OAT (1.79; 1.38-2.33), past-year opioid overdose (1.68; 1.18-2.42) and older age (1.02; 1.00-1.03) were associated with acquisition. Primarily injecting methamphetamine (versus heroin) in the past month was associated with lower awareness (0.43; 0.31-0.58) and acquisition (0.59; 0.44-0.78). Reporting no accommodation (squatting/sleeping rough) was associated with reduced odds of carriage (0.46; 0.24-0.88).

Conclusion: Participants reported high THN awareness and acquisition, with lower carriage. Future efforts should focus on improving THN access and reducing barriers to carriage, particularly for people experiencing homelessness or who primarily inject non-opioids.

Keywords: Injecting drug use; Naloxone; Opioid agonist treatment; Opioids; Overdose.