Medetomidine, a veterinary sedative, has started to saturate the fentanyl supply in Philadelphia and is moving to other cities throughout the East and Midwestern U.S.

The details:

Xylazine is fading from Philadelphia’s drug supply and being replaced by medetomidine, which is up to 200 times as potent.
Medetomidine is mostly manufactured in China and can be purchased cheaply online from suppliers of veterinary medicine and research chemicals. Because it is so potent, dealers don’t need to mix much into fentanyl.

Why it’s important:

Medetomidine can cause life-threatening withdrawal symptoms. While heart rate slows drastically right after use, in withdrawal, heart rate and blood pressure become catastrophically high, which can cause brain damage.
Medetomidine also causes almost instantaneous blackouts. As temperatures drop, there are increased concerns about people collapsing outdoors from medetomidine.
Patients experience tremors and unstoppable vomiting and may require intensive care.

The bigger picture: It has created a new type of crisis caused by withdrawal, rather than overdose.

Doctors have created a treatment protocol for medetomidine withdrawal that includes an intravenous drip of dexmedetomidine, a human-safe sedative cousin of medetomidine.
But: Many do not seek treatment for fear that withdrawal will not be adequately managed. And because medetomidine withdrawal is not yet a recognized diagnosis that requires extended hospitalization, reimbursement is limited, creating barriers for hospitals providing this care. Doctors are also struggling with how to safely discharge stabilized patients, as many are homeless and some are temporarily cognitively impaired.