Medetomidine
Medetomidine is a non-opioid sedative and anesthetic used in veterinary medicine that is around 200 times more powerful than xylazine.
It is being added to fentanyl, as well as other street drugs and counterfeit pills. It can be included with xylazine as an adulterant, though in some areas, it has replaced xylazine as the most common drug adulterant.
Sedative effects can last between 2-3 hours but can be prolonged when combined with opioids. Initial effects can include:
- Very low blood pressure
- Slow heart rate
- Extreme sleepiness
- Trouble breathing
- Hypothermia
- Overdose
- Coma
While Naloxone may not fully reverse a medetomidine-involved overdose it should still be administered in suspected overdose cases due to the likely presence of opioids.
Withdrawal from substances containing medetomidine occurs within hours and can be life-threatening. Symptoms of withdrawal can include:
- Extremely high blood pressure (> 200)
- Fast heart rate (>140)
- Hallucinations
- Tremors
- Psychosis
- Vomiting
- Reduced alertness (staring, inability to talk)
Dial 911 for medical assistance in the event of an overdose or symptoms of Medetomidine withdrawal.
Sources: CDC MMWR: www.cdc.gov/mmwr/volumes/74/wr/mm7415a2.htm
Philadelphia Department of Public Health
Pennsylvania Department of Health
Fact Sheets
Research & Data
- Notes from the Field: Severe Medetomidine Withdrawal Syndrome in Patients Using Illegally Manufactured Opioids — Pittsburgh, Pennsylvania, October 2024–March 2025 (CDC)
- Notes from the Field: Suspected Medetomidine Withdrawal Syndrome Among Fentanyl-Exposed Patients — Philadelphia, Pennsylvania, September 2024–January 2025