Animal tranquilizer 'xylazine' being mixed with illicit drugs like coca and molly, warns FDA


The animal sedative xylazine has become an increasingly common cutting agent.

Nearly half of America’s street drugs are laced with a dangerous tranquilizer for animals, a study suggests.

More than 40 percent of samples tested in Rhode Island contained xylazine, which health officials say can cause “serious and life-threatening side effects.”

Sometimes known as ‘tranq’, xylazine is commonly used as a sedative or analgesic for cows and horses in veterinary medicine.

It became popular recreationally in Puerto Rico and started showing up in Philadelphia in the early 2010s, but has now started popping up elsewhere as well.

In November, the Food and Drug Administration (FDA) warned healthcare professionals that the drug was being used as a cutting agent in heroin, methamphetamine, cocaine and opioids to boost their effects and increase supply.

For their analysis, Brown University researchers analyzed 90 drug samples from the Toxicological and Ethnographic Drug Surveillance Testing program.

Although none of the drugs were sold as xylazine, forty contained the animal tranquilizer – mostly fentanyl.

Although the drug is plentiful in Rhode Island, researchers say most users and community workers don’t even know what xylazine is.

The FDA has warned healthcare professionals that it can be “difficult to tell” a xylazine overdose from an opioid overdose — both drugs cause the lungs to begin to fail.

But unlike opioids, xylazine overdoses cannot be reduced with naloxone, the emergency opioid overdose reversal drug. Another concern is that people can also become physically dependent on the drug.

This creates complications for addicts who want to start using a drug to treat their opioid use disorder, such as methadone.

When someone stops using fentanyl as part of this process, they also experience xylazine withdrawal.

Patients who abuse drugs contaminated with xylazine can also experience ulcers and sores that “take a long time to heal,” Chelsea Shover, an assistant professor at the University of California, Los Angeles, told ABC.

Xylazine was involved in up to 20% of overdose deaths in the worst-affected states last year, including Massachusetts, Connecticut, Illinois and Pennsylvania.

Sold under the brand name Rompun in the United States, it first gained popularity in Puerto Rico in the 2000s, where it is known as ‘anestecia de caballo’.

It became a common heroin adulterant, an inexpensive way for dealers to improve the drug’s absorption and increase its potency.

In Puerto Rico, xylazine has been most prevalent in a drug combination dubbed the ‘speedball’, which is made up of heroin and cocaine and is used to balance the effects of both the depressant and the high.

A 2008 study found that over 90% of syringes used for speedballs tested in Puerto Rico contained xylazine.

Public health authorities were tipped off in part because of the appearance of ulcers on the skin of users where they injected the drug.

Painful lesions often get worse when users repeatedly inject into the same site, hoping to benefit from the analgesic effect of the opioid.

The drug left a stain on Philadelphia, home to the largest open-air narcotics market for heroin on the East Coast.

Between 2010 and 2015, xylazine was detected in 40 of Philadelphia’s 1,854 unintentional overdose deaths (just two percent) with heroin and/or fentanyl detections.

The presence of xylazine in Philadelphia has increased since then.

In 2017, it was detected in 10% of fentanyl and/or heroin overdose deaths, 18% in 2018 and 31% in 2019.

In 2020, xylazine was present in nearly 26% of overdose deaths in Philadelphia, followed by about 19% in Maryland and 10% in Connecticut.

What is xylazine?

Xylazine is a non-opioid agent originally approved by the FDA in 1972 as a sedative and analgesic for use in veterinary medicine.

The drug acts as a central alpha-2-adrenergic receptor agonist in the brainstem, causing a rapid decrease in the release of norepinephrine and dopamine in the central nervous system (CNS).

Xylazine can also bind to other CNS receptors, although more research is needed.

Xylazine is not approved for use in humans.

symptoms and risks

Signs and symptoms of acute xylazine toxicity can include difficulty breathing, high blood pressure, slow heart rate, hypothermia and high blood sugar levels.

Overdose overdoses can appear similar to opioid overdoses, making it difficult to distinguish.

But unlike opioids, xylazine overdoses cannot be reduced with naloxone, the emergency opioid overdose reversal drug.

Repeated exposure to xylazine, by injection, has been associated with severe necrotic skin ulcerations that are distinctly different from other soft tissue infections (eg, cellulitis, abscesses) often associated with injecting drug use.

These sores may develop on areas of the body far from the injection site.