Given the recent NYT article describing the life withdrawal crisis from medetomidine in Philadelphia, it’s a good time to review the medication.
Background
Veterinary alpha-2 agonist
100-200 times more potent then xylazine
An adulterant found in fentanyl supply
Action is most similar to clonidine and dexmedetomidine
Overdose result in prolonged sedation
Overdose Response
Naloxone
After giving naloxone patient may still be sedated
Administer the amount of naloxone needed to restore breathing
Withdrawal Symptoms
Symptoms begin abruptly with rapid progression within hours of last use
Symptoms peaking within 18-36 hours
Tachycardia
Severe hypertension
Waxing and waning alertness
Tremor- also described as myoclonic jerks
Intractable vomiting
End organ damage
NSTEMI
Posterior Resolving Encephalopathy Syndrome (PRES)
Treatment of Withdrawal
Early initiation of alpha-2 agonist
Clonidine is preferred
Tizanidine or guanfacine can be given in addition to clonidine if needed.
Anxiety and restlessness management
Olanzapine is preferred
Consider hydroxyzine and benzodiazepines
Pain
Acetaminophen and NSAIDs to start with
Short acting opioids and ketamine preferred if need stronger pain medications
References
Medetomidine Withdrawal Symptoms and Treatment. The New York Times. https://www.nytimes.com/2025/12/15/health/medetomidine-withdrawal-symptoms-treatment.html. Published December 15, 2025. Accessed December 17,2025.
Commonwealth of Pennsylvania. Medetomidine Guidance. https://www.pa.gov/content/dam/copapwp-pagov/en/health/documents/topics/documents/2025%20HAN/2025-794-06-18%20Medetomidine%20Guidance.pdf. Published June 18, 2025. Accessed December 17, 2025.
Substance Use Philly. Medetomidine. https://www.substanceusephilly.com/medetomidine. Accessed December 17, 2025
Centers for Disease Control and Prevention (CDC). Title of the article. MMWR Morb Mortal Wkly Rep. 2025;74(15) https://www.cdc.gov/mmwr/volumes/74/wr/mm7415a3.htm. Published April 15, 2025.