The dangers of xylazine – aka “tranq”

William Richardson, MD

Emergency Medicine

A drug called xylazine, which is used by veterinarians to sedate large animals, is causing an increasing number of overdose deaths in the U.S., according to the Centers for Disease Control and Prevention (CDC).

William Richardson, MD, an emergency medicine physician and medical toxicologist, explained what to know about this dangerous drug, including symptoms to look for and what to do if someone may have taken xylazine.

What exactly is xylazine?

Xylazine (also known as “tranq,” short for tranquilizer) is a non-opioid sedative commonly used in veterinary practices for the sedation of large animals. It’s not approved for human consumption.

What effect does xylazine have on humans?

Typical symptoms include:

• A low level of alertness
• Slow breathing and heart rate
• Dangerously low blood pressure

There have also been reports that, in some cases, when the drug is accidentally injected into the soft tissue instead of the vein, it can cause skin wounds that are easily infected, leading the surrounding tissue to die and rot. This is known as necrosis.

“There are a lot of drugs and chemicals that can cause that type of reaction,” Dr. Richardson said. “This appears to be one of them.”

How are people exposed to xylazine?

Xylazine is usually found in illegal street drugs such as fentanyl, cocaine and heroin.

“A lot of times adulterants like this are put into a drug to increase the quantity and make the dealer more money or enhance and prolong the high,” Dr. Richardson said. “Most of the surveys have shown that people aren’t necessarily looking for xylazine, they’re looking for fentanyl. Xylazine has been cut into the drug because it’s probably cheaper and more accessible.”

In samples from syringe programs in Maryland, tested between 2021 and 2022, xylazine was found in almost 80% of drugs samples that contained opioids, according to the CDC. In Philadelphia in 2019, it was found in 31% of overdose deaths involving heroin or fentanyl.

What can you do if you suspect a xylazine or “tranq” overdose?

The CDC recommends calling 911 and then administering Narcan if you have it. Because xylazine is not an opioid, Narcan won’t work on it, but it’s often difficult to know what has been taken. If the person has taken fentanyl cut with xylazine, it can help reverse the effects of the fentanyl. If the person has only taken xylazine, taking Narcan won’t cause additional harm.

Dr. Richardson said the combination of fentanyl and xylazine has made overdose treatment more of a challenge.

“In the emergency department, we will see what looks like a typical opioid overdose where someone is not breathing or they’re unconscious and breathing very slowly, and so we administer Narcan and we’ll see a partial or incomplete response,” he said. “In those cases, we will offer supportive care to deal with the effects. It may be necessary to intubate someone and put them on a ventilator to help them breathe. If they have low blood pressure or a low heart rate, we will give them medications to help. We can treat some of the symptoms of a xylazine overdose with supportive care, but there’s not a specific antidote or reversal agent like we have with Narcan which works so effectively for an opioid overdose like fentanyl.”

The main takeaway

It’s important to be aware of the risk of xylazine in drugs that are purchased illegally or online. If you or someone you love needs help with opioid addiction, talk to a health care provider.