An adulterant in fentanyl is creating a new crisis of withdrawal symptoms for users and provoking public concern in multiple U.S. cities.
The new drug, a veterinary sedative called medetomidine, is now widespread in the fentanyl turning up in Philadelphia, according to a report from a forensic testing lab. This crisis is not a result of overdosing on medetomidine, but of the withdrawal that patients experience within hours of using.
