LAS VEGAS (KLAS) — A report out of Arizona indicates a new worry in the fight against fentanyl use.

Xylazine, a sedative used on horses and cattle, has been detected in opioid-related overdoses. The drug is apparently being used by criminal drug networks to cut fentanyl, according to the Yuma County Sheriff’s Office.

Authorities say Xylazine overdoses cannot be reversed with Naloxone (Narcan).

The Yuma County Sheriff’s Office said, “Multiple state departments have reported the presence of Xylazine in opioid-related overdoses. These drug trafficking organizations are currently running this product through U.S. communities with common street names of ‘Tranq Dope’ and ‘Zombie Drug.’ “

(Yuma County Sheriff’s Office)

A report last week indicated public health warnings have been issued in New York City, Los Angeles and San Francisco. Philadelphia was the first U.S. city to document the “tranq trend.”

Xylazine is a tranquilizer commonly used as an animal sedative by veterinarians on horses and cattle.

“This substance is not safe for human use and causes deadly symptoms such as excessive sleepiness, respiratory depression, slowed heart rate, skin rotting, and most importantly, these overdoses CANNOT be reversed with Naloxone (NARCAN),” the sheriff’s office said.

Authorities urge parents to talk with children about the facts and dangers of drugs. Need help starting the conversation? Visit