PHILADELPHIA (WPVI) — Hospitals and health officials are warning about a dangerous shift in the illicit drug supply after testing revealed fentanyl is being mixed with medetomidine, an animal tranquilizer up to 200 times stronger than xylazine.
The Philadelphia Department of Public Health began receiving alerts from hospitals in April of last year about patients arriving with unusually low heart rates and prolonged sedation.
“Folks were coming in with very low heart rates, long periods of sedation, and they were concerned someone changed the supply,” said Dr. Daniel Texeira da Silva of the health department.
Testing confirmed the presence of medetomidine, which experts say is now widespread.
“On average, there is twice as much medetomidine as fentanyl in a bag of dope,” said Christopher Moraff, founder of PA Groundhog, a grassroots organization that monitors the drug supply and advocates for safer alternatives.
Moraff described the drug’s effects as extreme.
“They basically face planted on the floor and basically snored for six hours the whole time,” he said.
According to Moraff, 80% of the samples his group tests are positive for medetomidine.
Unlike xylazine, which is known to cause severe skin lesions and amputations, medetomidine is creating intense withdrawal symptoms that have overwhelmed local hospitals.
“When people stop using, they can experience very high heart rates, high blood pressure, they can have vomiting and nausea that can’t be controlled, tremors, and many people end up in the ICU,” Texeira da Silva said. Moraff added, “I know people that are far more dependent on the medetomidine than on the fentanyl.”
The health department says identifying overdoses has become more complicated because users may not respond to Narcan but continue breathing, leading to confusion during emergencies.
“We’re working very closely with hospitals, with providers, community-based providers, to identify these changes quickly and respond quickly. I worry about it, but I know we’re ready to,” Texeira da Silva said.
Comparing the first quarter of this year to last, emergency room visits for withdrawal symptoms have risen more than 130%, according to the health department.
Copyright © 2025 WPVI-TV. All Rights Reserved.