Medetomidine, an animal sedative, mixed into fentanyl has sent thousands to hospitals in Philadelphia, not only for overdose but for life-threatening withdrawal. It is spreading to other cities.

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.