RESUMEN
INTRODUCTION: The administration of illicit drugs by injection is associated with considerable harm, including an increased risk of overdose. The chemical analysis of used syringes can enhance knowledge on injecting drug consumption beyond traditional data sources (self-report surveys). This additional information may be useful during significant global events like the COVID-19 pandemic. This study aimed to examine a snapshot of the drugs injected at the Medically Supervised Injecting Centre (MSIC) in Sydney, Australia, in 2019-2020. METHODS: Used syringes were collected from MSIC across three periods throughout 2019 and 2020 (February 2019, March-April 2020 and June-September 2020). Drug residues were extracted from used syringes using methanol before detection by gas chromatography-mass spectrometry and ultra-performance liquid chromatography-tandem mass spectrometry. The chemical analysis results were compared to self-report data obtained from MSIC clients. RESULTS: Heroin (46-53%), methamphetamine (24-34%) and pharmaceutical opioids (15-27%) were the most common drug residues detected. The chemically detected drugs had declining coherence with the drugs self-reported by MSIC clients across the time periods examined. DISCUSSION AND CONCLUSIONS: There was no significant change in the drugs injected (heroin, methamphetamine and pharmaceutical opioids) across the three periods collected throughout varying COVID-19 lockdown restrictions. Changes in the frequency of other drugs injected and discrepancies between chemical analysis and self-report were potentially related to regulatory changes, degradation or misinformed sales. Routine chemical analysis of used syringes has provided an alternative information source to promote awareness of current drug trends and aid harm reduction.