Trends in Tranq: prevalence of xylazine and medetomidine in oral fluid toxicology among Great Lakes States.

Background

Xylazine and medetomidine (each sometimes referred to as "Tranq") are animal tranquilizers commonly and sometimes unknowingly used with illegal drugs, primarily fentanyl. In the United States, xylazine appeared in the Northeast beginning in the late 2010s, preceding medetomidine beginning in 2022. Current trends in the Great Lakes region west of this origin have not been thoroughly investigated.

Objectives

Identify drug use trends associated with xylazine and medetomidine specific to five states comprising the Great Lakes region.

Methods

From March 2023 through May 2025, 86,093 oral fluid specimens were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS-MS) following a presumptive positive screen for illegal substances using enzyme-linked immunosorbent assays (ELISA). Samples primarily originated from child protective, court, and probation services. Results and geospatial metadata from samples were used for analysis and discrete heatmap generation.

Results

In xylazine- or medetomidine-positive cases, fentanyl was present over 95% of the time. Multiple drug classes were frequently detected in these cases. Each adulterant increased in prevalence among fentanyl-positive cases over their respective periods of study, converging to around 32%. Heatmaps of xylazine and medetomidine positivity rates showed that the prevalence of xylazine diminished in most states, while all states increased in prevalence for medetomidine.

Conclusions

Medetomidine has been rapidly adopted as an adulterant in drug markets among Great Lakes states and is now frequently used alongside xylazine. Understanding regional trends regarding these adulterants can inform health-care professionals and policymakers of the spread and adoption of emergent drug use practices to improve public health.