Researchers Test Harm Reduction Tool Xylazine Test Strips

In collaboration with the City of Philadelphia Department of Public Health (DPH), researchers at the Center for Forensic Science Research and Education (CFSRE) have tested xylazine test strips to detect the substance in opioids. Investigators and public health professionals postulate that this could be a critical harm-reduction tool for opioid users.

For decades, the opioid crisis has plagued the United States, contributing to most drug overdoses and thousands of deaths. According to data in a StatPearls textbook, 18% of the 16 million people with opioid use disorder (OUD) worldwide are in the US.

Although federal organizations, private establishments, and providers have worked to minimize OUD, drug overdoses, and other fatal factors associated with opioid use, they have been unable to manage laced opioid supplies.

Recently, the Philadelphia DPH announced that over 90% of opioid samples had included xylazine, a veterinary tranquilizer, sometimes called tranq. Research and samples from 2021 note that xylazine is often combined with street fentanyl or heroin.

According to the CFSRE, xylazine is associated with sedation, altered mental status, and skin ulcerations or wounds. The FDA also notes that xylazine use can cause CNS and respiratory depression, leading to the cessation of breathing. Additional side effects of this veterinary medicine include hypotension, bradycardia, hypothermia, and high blood glucose levels.

Beyond the fatal dangers of use, xylazine is highly addictive, leading to dependence and withdrawal symptoms, such as agitation or anxiety. Since the drug is not an opioid or approved in humans, overdose reversal drugs like naloxone are ineffective, significantly increasing the risk for people with OUD.

Because naloxone is becoming a standard harm-reduction tool for individuals with OUD and is ineffective against xylazine, clinicians and public health professionals sought an alternative harm-reduction strategy.

The search yielded xylazine test strips manufactured by BTNX Inc. Investigators at CFSRE evaluated the efficacy and validity of these tools, finding 100% sensitivity, 85% specificity, and 91% precision. Clinicians concluded that these tools were an acceptable harm-reduction strategy, stipulating that lidocaine is an interferant and may affect results.

Researchers in the study noted, “Future studies will be explored, including continued testing of authentic samples, testing of additional XTS batch lots, added drugs for interference studies and macro-dose interference studies to test higher concentrations of drugs, and assessment of the test strips using mock and authentic urine specimens, among other research opportunities.