CDC issues warning about ‘rhino tranq,’ a mix of fentanyl and animal sedative medetomidine that resists overdose reversal meds

LOS ANGELES () — You may have heard about the street drug “tranq.” It’s an animal tranquilizer mixed with fentanyl. Now there is a new CDC warning about a stronger version called “rhino tranq,” which doesn’t respond effectively to life saving medications like fentanyl alone does.

“Rhino tranq” is an emerging, highly-risky street drug. It’s a mix of fentanyl with the animal tranquilizer medetomidine.

“Can be dangerous when people use it, because it can increase the rate of overdose, it can increase the rate of low blood pressure and other cardiovascular complications,” said Dr. Brian Hurley, the medical director of substance abuse prevention and control with the L.A. County Department of Public Health.

He compared it to “tranq,” which is a combination of fentanyl and another veterinary relaxant called xylazine. Hurley said medetomidine, which is found in ‘rhino tranq,’ is far more dangerous.

“Medetomidine is actually more potent than xylazine is, and they both seem to be associated with increased risk of overdose,” Hurley said.

The CDC issued a new warning to health care professionals on Thursday. Medetomidine, which is also known as “mede” or “dex,” is being picked up in seized drugs and wastewater samples. The highest concentration is in the Northeast.

“So it’s not present here at the same degree that is present in other cities on the East Coast, like Philadelphia,” Hurley said. “At the same time, we do think it’s important that the public and the medical providers here in Los Angeles be aware that medetomidine is here.”

He said when people experience a fentanyl overdose with medetomidine, they don’t respond effectively to the opioid reversal drug naloxone.

“Naloxone doesn’t address medetomidine intoxication, nor does it touch medetomidine withdrawal. So, that’s why people will need other supportive care,” Hurley said.

Overall in L.A. County, fentanyl-related deaths have dropped 37% in 2024 compared to 2023. But far too many overdoses are still happening and Hurley said people need to know “rhino tranq” is out there.

“The safest thing is to not use drugs, but if somebody is thinking about using, never use a loan, have naloxone on hand, and consider using test strips to look at what’s in the drug supply,” he said.

He said the county provides free fentanyl testing strips through their community health stations located at various schools, hotels and churches. You can see those locations on their website.