Submitted by Dr. Joanna Jung, Associate Editor
The article “Xylazine Pharmacokinetics in Patients Testing Positive for Fentanyl and Xylazine”, published in the February 2025 issue of Clinical Chemistry, addresses the knowledge gap in the pharmacokinetics of xylazine. Understanding how xylazine behaves in patients with fentanyl exposure is crucial for managing potential overdoses. Xylazine, a sedative commonly used in veterinary medicine, is increasingly being found as a contaminant in illicit fentanyl products, raising concerns about its effects on humans. Healthcare providers need to consider the interaction between these two substances, as xylazine’s sedative effects can complicate the management of fentanyl overdose.
The authors overcame challenges related to studying drug adulterants that are not approved for human use by utilizing remnant samples. They acknowledge several limitations in their data.
One of the key findings was that xylazine’s elimination half-life may be prolonged in patients co-exposed to fentanyl, increasing the risk of prolonged sedation or respiratory depression, which is further compounded by fentanyl’s effects.
The article emphasizes the need for more research into the pharmacokinetics of xylazine, particularly in the context of fentanyl co-use, to improve treatment strategies for patients and better understand the risks associated with this combination.