Widespread Distribution of Xylazine Detected Throughout the United States in Healthcare Patient Samples

Abstract Methods: Samples for which providers ordered testing for xylazine were subjected to enzymatic hydrolysis, extracted, and analyzed using liquid chromatography–tandem mass spectrometry. Retrospective analysis was performed on xylazine-positive samples collected from April 2021 to March 2022, to include geographic location and copositive substances. Results: Xylazine was identified in 413 of 59,498 samples from adults aged 20–73 years and originated from 25 of the 39 states where xylazine testing was ordered. The most common routine substances detected with xylazine were