Understanding Medetomidine and Its Risks

Yes – you read that right – in recent years a flesh-eating drug, known as xylazine (or Tranq) has emerged on the streets of the US and is causing concern among health officials and communities alike.

What is Xylazine?

Xylazine is a veterinary tranquilizer (which comes as either a clear injectable liquid or white powder/pill) that is primarily used to calm and sedate large animals such as horses and cattle. It is NOT approved for human use.

Illicitly it can appear as a white or brown powder. Often, unknown to users, it can be found mixed with opioids and other illicit drugs, particularly fentanyl. While Philadelphia, PA still has the highest rates of xylazine use, according to the U.S. Drug Enforcement Administration (DEA), it has been found in fentanyl mixtures in 48 out of 50 states and has issued warnings about the rising prevalence of this dangerous combination, noting that it significantly increases the risk of fatal overdoses.

Scary Statistics

In Philadelphia during 2022, 34% of the city’s 1,413 unintentional overdose deaths involved xylazine, and of those almost all also involved fentanyl.
The DEA reports that in the eastern and southern states, tranq supplies have jumped 61% and 193%, respectively, between 2020 and 2021.
About 30% of Fentanyl that has been seized off the streets by the DEA contains xylazine.
Southern California is also seeing an uptick in cases through its US-Mexico drug trade. A recent San Diego and Tijuana bi-national 24 hour study held at a harm reduction clinic (and published in The Journal of Addiction Medicine on March 20, 2025) found that the majority of the users whose urine was tested were positive for xylazine. As many as 82.6% of the samples tested positive.
Recent news has xylazine being blamed for 25% of fentanyl overdose deaths.

Xylazine Street Names

Impairing the user’s ability to stand up straight, this drug has also garnered the nickname “zombie drug” in addition to its other chilling moniker “flesh-eater”.

Side Effects of Xylazine

The most common side effects of xylazine include:

Impaired judgment/confusion/disorientation
Hypotension (dangerously low blood pressure)
High blood sugar
Miosis (pinpoint/constricted pupils)
Blurred vision
Hypoventilation (respiratory depression)
Bradycardia (slow heart rate)
Coma
Slurred speech, trouble swallowing, and slower reflexes
Drowsiness/lethargy and/or sedation
Amnesia

Its continued usage can lead to extreme dependence and severe withdrawals.

One of the most alarming aspects of xylazine is its potential to cause severe tissue damage. It is an animal-grade sedative and muscle relaxant, and the human body cannot naturally process it. Since xylazine lowers heart rate and blood pressure and constricts blood vessels causing disease of the small vessels – it restricts blood flow to the skin and soft tissue thus starving it of nutrients and oxygen.

US correspondent David Woiwood, with 7News Australia, reported from the streets of Philadelphia a couple of years back describing the impact of fentanyl and xylazine while interviewing addicts and visiting wound and treatment clinics. Drugs that contain xylazine burn through the skin of users, causing skin ulcers and necrosis (the rotting of human flesh) — literally eating them alive. The dead tissue can look black and yellow and can lead to serious infections and possible amputations.

Patient Stigma

In an interview with The Conversation US, emergency room nurse Rachel McFadden, with the University of Pennsylvania Hospital and a wound care clinic in North Philadelphia, that serves people who use drugs and has seen an uptick in necrosis cases, discussed the stigma associated with addiction. Here are a few of the issues users face:

Whether as a result of the attitudes of healthcare workers or policies in place with certain institutions, addicts experience issues obtaining timely medical care and other help.
A limited availability to free or low-cost wound care clinics.
Some may be denied access to rehab/detox centers until their wounds have healed.
They experience humiliation at clinics because of their wounds.
Some users are denied surgical wound care intervention due to drug use.

Why is Xylazine So Dangerous?

Some users claim xylazine knocks them out for six to eight hours and additionally, its sedative effects can lead to dangerously slowed breathing and heart rates, further increasing the risk of death.

According to Matt Johnson, a drug user and harm reduction worker at the Parkdale Queen West Community Health Centre in Toronto: “It puts people in sort of blackout states, people are at really high risk of walking into traffic because they don’t really know what’s going on.”

Unlike opioids, it does NOT respond to naloxone (Narcan), the life-saving medication used to reverse opioid overdoses. This makes overdoses involving xylazine particularly deadly, as there is no effective antidote available. But since xylazine is frequently mixed with opioids, the NIDA states that opioid overdose reversal medication naloxone should be used during a suspected xylazine overdose. However, because xylazine isn’t an opioid, naloxone may not reverse the effects of the drug.

Conclusion

At present xylazine is not included in routine immunoassay testing so it is most likely being under-reported. Yet the rise of xylazine in the illicit drug market is a stark reminder of the ever-evolving nature of the drug crisis. We are already struggling with the fentanyl and opioid crisis and the emergence of xylazine has made the threat that more dangerous. As communities and health officials grapple with this new threat, it is crucial to stay informed and take proactive steps to protect those at risk. By raising awareness and promoting harm reduction, we can help mitigate the devastating impact of this flesh-eating drug.

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