Veterinary Drug Emerges as New Threat in U.S. Illicit Drug Supply
A veterinary sedative used in dogs and cats is making its way into the U.S. illegal drug supply, contributing to severe and sometimes deadly overdose clusters across multiple states. According to a recent CDC report, illicit medetomidine—a non-controlled veterinary sedative—has been identified as a new adulterant in street drugs, often found in combination with fentanyl or heroin.
First detected in Maryland in 2022, illicit medetomidine bulk powder has now appeared in California, Colorado, Illinois, Missouri, and Pennsylvania. By early 2025, overdose clusters linked to the drug had occurred in major metropolitan areas such as Chicago, Philadelphia, and Pittsburgh.
What Is Medetomidine? Medetomidine is FDA-approved for use in dogs for sedation and pain relief and is often used off-label in cats and other small animals. It is a racemic mixture containing dexmedetomidine (the pharmacologically active enantiomer) and levomedetomidine. While dexmedetomidine is FDA-approved for human ICU sedation, medetomidine itself is not authorized for human use and is not a controlled substance.
Clinical Findings and Overdose Patterns Overdose symptoms associated with illicit medetomidine include:
Bradycardia (slow heart rate)
Altered mental status
Poor response to naloxone
In a May 2024 Chicago outbreak, 181 suspected opioid overdoses were reported at three hospitals within one week. Of these, 12 confirmed cases involved medetomidine.
Philadelphia experienced a distinct withdrawal syndrome between September 2024 and January 2025. A total of 165 individuals required hospitalization, with nearly 25% needing intubation. Traditional opioid treatments failed, but dexmedetomidine proved effective.
Pittsburgh saw a similar pattern, with 10 confirmed medetomidine-involved cases between October 2024 and March 2025. Nine required ICU care for severe autonomic symptoms, including hypertension and agitation.
Public Health Concerns Experts are sounding the alarm. A commentary in The Lancet (April 2025) stated that medetomidine’s potency—200 to 300 times that of xylazine—and its growing presence in the illicit drug supply are cause for immediate concern.
Calls to action include:
Development of medetomidine-specific overdose treatment protocols
Expanded surveillance to monitor its spread
Multi-agency collaboration to coordinate response efforts
FAQ: What You Need to Know
Q: What is medetomidine used for in veterinary medicine? A: Medetomidine is a sedative and analgesic used in dogs and cats for procedures requiring calmness and pain control.
Q: Is medetomidine dangerous to humans? A: Yes. When used illicitly or in combination with other drugs, it can cause severe sedation, bradycardia, and may not respond to traditional opioid reversal agents.
Q: Can naloxone reverse a medetomidine overdose? A: No. Naloxone is often ineffective. Dexmedetomidine has been used successfully to counteract some of the symptoms.
Q: Why is this drug turning up in street drugs? A: It is not currently a controlled substance and may be easier to acquire in bulk. Its sedative effects are likely being used to enhance or extend opioid highs.
Q: What can be done to address this crisis? A: Clinical guidelines must be developed urgently, epidemiological tracking expanded, and multi-sector partnerships formed to mitigate future outbreaks.
Medetomidine represents the latest dangerous twist in America’s overdose epidemic, reinforcing the need for both vigilance and innovation in public health response.
