UBC Faculty Research and Publications

Characterizing the presence of fentanyl analogues in the unregulated drug supply in British Columbia, Canada Crepeault, Hannah; Socias, M. Eugenia; Tobias, Samuel; Lysyshyn, Mark; Custance, Allen; Shapiro, Aaron M.; Ti, Lianping


Background: The emergence of fentanyl and its analogues (e.g., carfentanil) have contributed to a rise in overdose-related mortality. The objective of this study was to describe samples containing fentanyl analogues appearing in the unregulated drug supply of British Columbia (BC), Canada. Methods: Point-of-care drug checking data, using a combination of fentanyl immunoassay strips and Fourier-transform infrared spectroscopy (FTIR), were collected at harm reduction sites in BC between 2017 and 2021. A subset of samples were sent for confirmatory analysis using quantitative nuclear resonance spectroscopy, gas chromatography-mass spectrometry, and/or liquid chromatography-mass spectrometry. Results: A total of 22916 samples were tested using point of care technologies, with 43% testing positive for fentanyl via fentanyl test strips. 1467 were sent for confirmatory analysis, and of these 854 (58%) tested positive for fentanyl via fentanyl test strips and 84 (6%) contained at least one fentanyl analogue, including: carfentanil (n=61), acetyl fentanyl (n=15), furanyl fentanyl (n=8) and cyclopropyl fentanyl (n=5). Fourteen (16%) samples containing a fentanyl analogue tested negative via fentanyl immunoassay strips and fentanyl was also not detected using FTIR. Fentanyl analogues in all fourteen samples were identified in trace amounts via confirmatory analysis. Conclusion: Fentanyl analogues were present in the unregulated drug supply and while the risk profiles are known for some, not all are well characterized. These findings underscore the importance of drug checking initiatives for monitoring the unregulated drug market.

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