Background: Understanding drug use trends among people who inject drugs (PWID) is frequently based on self-reported data. Whilst insightful, it can be subjective and provides limited specifics on the drug composition. The chemical analysis of the residual drug content in used syringes has been shown to complement self-reported information. Chemical analysis can confirm the main drug injected and detect other components, such as adulterants. Injecting drug use is a dynamic; hence a longitudinal analysis might provide greater insight into market behaviours and the preferences of PWID.
Objectives: This study aims to examine the residual drug content of used syringes over time to observe trends in injecting drug use.
Methods: Used syringes were collected through multiple periods from July 2022 until early 2024 from the Medically Supervised Injecting Centre (MSIC) and four needle and syringe program (NSP) locations in Sydney. The residual content was extracted before gas chromatography - mass spectrometry (GC-MS) detection; the results were compared to the drugs self-reported by MSIC clients.
Results: Heroin, methamphetamine and pharmaceutical opioids were the most common drugs injected; sample dependent. Adulteration (for example, with 2’-fluoro-2-oxo PCE) and polydrug mixtures (heroin/methamphetamine mixtures) remained low throughout all samples.
Implications: This research aligns well with Australia’s harm minimisation approach to drugs. It holds great potential for harm reduction at the individual level for PWID by providing insights into the current drug market. This could be further enhanced by the provision of a drug-checking service at MSIC.
Harrison is a PhD candidate at the University of Technology Sydney, and he is passionate about the illicit drug problem, forensic drug chemistry and forensic intelligence. His research involves the analysis of used syringes to improve current knowledge of trends in injecting drug use in collaboration with the Uniting Medically Supervised Injecting Centre. Harrison is also currently using near-infrared spectroscopy to optimise chemometric models for identifying and quantifying illicit drugs in real-time within Australia, in collaboration with the Australian Federal Police and the University of Lausanne.