Data gathered by the Toxicology Investigators Consortium (ToxIC) Fentalog Study was reported in the CDC’s August 1, 2024 Morbidity and Mortality Weekly Report (MMWR) “Notes from the Field: Medetomidine, a clinical and veterinary medication similar to xylazine, detected in patients presenting to the emergency department following suspected opioid overdoses - Missouri, Colorado, and Pennsylvania, September 2020-December 2023.”

This publication presents a detailed evaluation of 5 confirmed opioid overdoses in which medetomidine was detected. Medetomidine is a veterinary agent used for its anesthetic and analgesic properties in dogs. It has been reported in illicit drug samples from Maryland over the last year, but has not previously been reported in humans after recreational drug use until now. In addition to medetomidine, comprehensive toxicology blood testing demonstrated the presence of other concomitant drugs, including fentanyl in three patients, illicit benzodiazepines in three, stimulants in three, xylazine in three, and nitazene opioids in two. This is the first report demonstrating medetomidine in the blood of patients after opioid overdose. According to the report's first author, Evan Schwarz, MD, “Adulterants such as medetomidine have been found in 3 states, and there is an emerging concern for exposure in the United States. Concurrent exposure to both medetomidine and opioids may increase overdose risk in patients, and can complicate the approach to treatment.”The ToxIC Fentalog Study collects data from 10 geographically diverse hospitals in 9 states to identify risk factors and evaluate optimal treatments for nonfatal overdoses involving fentanyl, fentanyl analogs (fentalogs), illicit benzodiazepines, and adulterants (such as xylazine). Now in its 4th year, the study has enrolled over 1800 patients. Data derived from this study are used to characterize synthetic opioids used, evaluate treatments, and track regional trends in fentalog overdoses.For more information on the ToxIC *Fentalog Study and to see quarterly toxicology testing reports released by Center for Forensic Science Research and Education (CFSRE), view the ToxIC Fentalog Study webpage. Study findings are also disseminated through ToxIC partners at the Centers for Disease Control and Prevention via an interactive data dashboard. 

The Toxicology Investigators Consortium (ToxIC) is a multicenter toxicosurveillance and research network that detects new drugs of abuse, monitors adverse effects of post-marketing medications, and identifies emerging toxicological threats. Led by medical toxicology physicians and registry experts, our projects involve case registry design and maintenance.The American College of Medical Toxicology (ACMT) is a professional, nonprofit association of physicians board certification in medical toxicology and other professionals with expertise in this area. ACMT members specialize in the prevention, evaluation, treatment, and monitoring of injury and illness from exposures to drugs and chemicals, as well as biological and radiological agentsm and work in clinical, academic, governmental, and public health settings, and provide poison control center leadership. *FundingResearch reported in this publication was supported by the National Institute on Drug Abuse of the National Institutes of Health under Award Number R01DA048009 (PI: Alex Manini). Supplemental funding is provided by the Centers for Disease Control and Prevention (Award Number 3R01DA048009-04S1) to increase the project’s testing capacity.

Jessica Irving
American College of Medical Toxicology
(844) 226-8333 
communications@acmt.net

Kim Aldy
Toxicology Investigators Consortium (ToxIC)
toxic@acmt.net