Drug checking: a harm reduction intervention to address the illicit drug toxicity crisis in a Canadian setting
Background: Canada is contending with an illicit drug toxicity crisis driven primarily by the unregulated opioid drug supply. In response, a number of evidence-based harm reduction initiatives have been implemented with the aim of reducing overdose deaths, including widespread availability of naloxone and medically supervised safer consumption sites. Drug checking is an intervention that offers people information about what is in street-obtained drugs to enable informed decision making. This project summarizes the viability of drug checking as a harm reduction intervention in British Columbia (BC), Canada. The objectives of this project were to: 1) examine the accuracy of point-of-care drug checking technologies (i.e., immunoassay strips, Fourier-transform infrared [FTIR] spectroscopy) in detecting substances; 2) determine the utility of community drug checking as a tool to monitor dynamics of the unregulated drug supply; and 3) to evaluate the feasibility, uptake, and possible behavioural modifications that result from drug checking for the purposes of informing future interventions.
Methods: Data for this project were collected from community harm reduction sites across BC between March 2018 and August 2023. A number of data sources were used, including: drug checking results data from FTIR spectroscopy and immunoassay strips (fentanyl and benzodiazepines); confirmatory analysis data using quantitative nuclear magnetic resonance spectroscopy, gas chromatography-mass spectrometry, and liquid chromatography-mass spectrometry; and a cross-sectional quantitative survey of a subset of individuals who have used drug checking services.
Results: In total, 86,736 samples were submitted to drug checking sites during the study period, and 381 unique individuals completed a survey. Our findings showed that the combined use of FTIR spectroscopy and immunoassay strips were beneficial in addressing the limitations of each of the technologies when used alone; however, issues with respect to detecting active substances below testing modality’s limit of detection remains. Results also revealed a rapidly changing unregulated drug market, with the presence of new adulterants (e.g., benzodiazepines, xylazine) and highly potent fentanyl analogues. Finally, our findings demonstrated that changes in overdose risk reduction practices (e.g., used less, disposed of drug) occurred more frequently among individuals who were not pleased with their drug checking results (p<0.05).
Conclusions: These findings collectively highlight how dynamic the unregulated drug supply is and point to the need for new investments in drug checking technologies to adapt to the changing market. Our findings also suggest the potential for drug checking services to reduce overdose risk by providing individuals with knowledge about the drugs they intend to consume or share.
