Substance Use Monitoring Among People Who Use Drugs Using a Novel Assay to Test Dried Blood Spot Specimens.

BACKGROUND AND AIMS

The development of comprehensive strategies to understand emerging trends in substance use is necessary to design effective prevention and harm reduction strategies for people who use drugs (PWUD). Dried blood spots (DBS) can be used as a non-conventional drug testing approach that meets Food and Drug Administration (FDA) accuracy and precision guidelines.

DESIGN, SETTING, AND PARTICIPANTS: From July 2021 to July 2022, 1,559 PWUD were enrolled at six US syringe service programs (SSP) in Sacramento, California, Ellensburg, Washington, and Missoula, Montana ("Western"), Madison, Wisconsin, New Haven, Connecticut, and Wilmington, North Carolina ("Eastern").

MEASURES

Participants completed a survey on demographic and behavioral characteristics and provided DBS specimens. A novel toxicology assay coupling liquid chromatography and tandem mass spectrometry was developed and used to identify the presence/absence of fentanyl, methamphetamine, xylazine, cocaine, and heroin, along with their metabolites. In this cross-sectional analysis, we describe the prevalence of each substance stratified by SSP.

RESULTS

Among 1,345 PWUD, methamphetamine was more prevalent in the Western versus Eastern state SSPs (95% vs. 33%). The Eastern state SSPs saw higher prevalence of cocaine, fentanyl, heroin, and xylazine than the Western state SSPs (86% vs. 24%; 41% vs. 11%; 20% vs. 17%; 20% vs. 6%, respectively). Testing positive for more than one substance was common (50%).

CONCLUSIONS

These results confirm existing regional differences in substance use. Further research is needed on the logistical implications of DBS and in which public health and research settings they may be useful.