medetomidine

A new drug has been saturating the fentanyl supply in Philadelphia and moving to other cities throughout the East and Midwestern United States: medetomidine, a powerful veterinary sedative that causes almost instantaneous blackouts and, if not used every few hours, brings on life-threatening withdrawal symptoms. It has created a new type of drug crisis — one that is occasioned not by overdosing on the drug, but by withdrawing from it. Since the middle of last year, Philadelphia’s hospitals have been strained by patients coming in with what doctors have identified as medetomidine withdrawal. Although the heart rate slows drastically right after use, in withdrawal the opposite occurs: The heart rate and blood pressure become catastrophically high. Patients experience tremors and unstoppable vomiting. Many require intensive care.

2025 December 15, Jan Hoffman, “A Powerful New Drug Is Creating a 'Withdrawal Crisis' in Philadelphia. Medetomidine, a veterinary sedative, mixed into fentanyl has sent thousands to hospitals, not only for overdose but for life-threatening withdrawal. It is spreading to other cities”, in The New York Times