An outbreak of novel psychoactive substance benzodiazepines in the unregulated drug supply: Preliminary results from a community drug checking program using point-of-care and confirmatory methods.

BACKGROUND: From mid-2018, an increase in novel psychoactive substance (NPS) benzodiazepines was noted on surveillance of the unregulated drug market around Vancouver, British Columbia, Canada. The rise was concordant with an outbreak of atypical overdoses suspicious for benzodiazepine adulteration of unregulated opioids. This study sought to describe the number and type of NPS benzodiazepines in a sample drawn from a community drug checking program during this period, and to explore accuracy of point-of-care drug checking technologies when compared to confirmatory methods in this sample. METHODS: Point-of-care drug checking data using fentanyl and benzodiazepine test strips as well as Fourier transform infrared spectroscopy were gathered at harm reduction sites in the Vancouver area from October 2018 to January 2020. A convenience subsample underwent confirmatory testing with gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, or quantitative nuclear magnetic resonance spectroscopy. RESULTS: Of 159 samples with both point-of-care and confirmatory results, 24 (15.1%) contained at least one NPS benzodiazepine, including etizolam (n = 18), flubromazolam (n = 3), flualprazolam (4), and flubromazepam (n = 1). Of 114 confirmatory samples expected by participants on self-report to contain opioids, 18 (15.8%) contained some NPS benzodiazepine, with 16 (14.0%) containing both an NPS benzodiazepine and an opioid, always fentanyl. False positive and negative rates were 15.5% and 37.5% for test strips, and 3.9% and 91.7% for FTIR, respectively. Combined together, false positive and negative rates of point-of-care methods were 17.8% and 29.2%. CONCLUSIONS: NPS benzodiazepine adulteration in an unregulated drug supply sample reveals new risks compounding ongoing harms associated with the synthetic opioid epidemic. Given substantial false positive and false negative rates noted in our sample for point-of-care detection methods, cautious use of combined point-of-care methods, routinely paired with confirmatory drug checking may aid in early detection and monitoring of unregulated drug markets and inform targeted harm reduction strategies and health policy approaches.

Drug checking as a potential strategic overdose response in the fentanyl era.

Adulteration of illicit drug supplies with synthetic opioids such as fentanyl has contributed to a dramatic rise in overdose morbidity and mortality in North America. One promising response to this crisis is the implementation of "drug checking" services. Drug checking encompasses a range of interventions used to assess the constituents of illicit drug samples, such as colour-spot testing, gas or liquid chromatography, and various methods of spectroscopy. Testing may be performed on-site at events or harm reduction service locales, performed independently by consumers, or sent to a centralized lab for analysis. This information may then serve to inform individual decision-making, enhance harm reduction efforts and strengthen public health surveillance and response strategies to prevent harms associated with illicit drug use. Historical examples of drug checking services that emerged with the 1990s synthetic "party drug" movement in Europe provide a theoretical and practical basis for the adaptation of these services for use in context of the current opioid overdose crisis. Potential harm reduction benefits of drug checking for synthetic opioid adulterants include individuals being more likely to use drugs more safely or to dispose of drugs found to contain harmful adulterants. Public health benefits of drug checking may also include negative feedback on the illicit drug supply with decreased availability or consumption of drugs from sources adulterated with synthetic opioids following public health warning campaigns. As part of the response to the current synthetic opioid epidemic in BC, pilot efforts are being undertaken in Vancouver to determine the feasibility and effectiveness of drug checking as an overdose response strategy. Models of drug checking service delivery and comparison of differing technologies, including unique challenges and potential solutions related to access to these services, legal obstacles, and sensitivity and specificity of testing technologies, are explored, alongside suggestions for future research and directions.