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

Area of Science:

• Public Health
• Toxicology
• Drug Use Epidemiology

Background:

• Comprehensive strategies are needed to understand emerging substance use trends.
• Dried blood spots (DBS) offer a viable, FDA-compliant method for drug testing.
• Effective prevention and harm reduction for people who use drugs (PWUD) rely on understanding current trends.

Purpose of the Study:

• To analyze the prevalence of specific substances among PWUD across different US regions.
• To investigate regional variations in the use of fentanyl, methamphetamine, xylazine, cocaine, and heroin.
• To assess the utility of DBS in a multi-site study of PWUD.

Main Methods:

• 1,559 PWUD were enrolled across six syringe service programs (SSPs) in Western and Eastern US states.
• Participants provided demographic data and DBS specimens for toxicology analysis.
• A novel liquid chromatography-tandem mass spectrometry assay identified fentanyl, methamphetamine, xylazine, cocaine, heroin, and their metabolites.

Main Results:

• Methamphetamine prevalence was significantly higher in Western SSPs (95%) compared to Eastern SSPs (33%).
• Eastern SSPs showed greater prevalence of cocaine (86% vs. 24%), fentanyl (41% vs. 11%), heroin (20% vs. 17%), and xylazine (20% vs. 6%).
• Polysubstance use was common, with 50% testing positive for more than one substance.

Conclusions:

• The study confirms existing regional disparities in substance use patterns.
• DBS proved effective for identifying multiple substances in PWUD.
• Further research should explore the logistical and practical applications of DBS in public health and research.