Xylazine, a fast-acting central nervous system depressant that is not approved for human use, is showing up largely in fentanyl, the ultra-potent synthetic opioid that is mixed into heroin and pressed into counterfeit pills and responsible for more overdose deaths than any other drug. Adding xylazine to fentanyl, which is also a depressant, increases the already high odds of overdose. It's a double whammy to the central nervous system. It "should be avoided at all cost," said UCLA researcher Joseph Friedman, who has studied the drug extensively.
In Michigan, xylazine has turned up in toxicology screenings of almost 200 people who have died from drug overdoses since 2019, said Varun Vohra, who is director of the Michigan Poison and Drug Information Center at Wayne State University in Detroit.
That number is certainly an undercount. Most hospital emergency department drug tests are not calibrated to detect xylazine and since a xylazine overdose looks similar to an opioid overdose ― pinpoint pupils, loss of consciousness, slowed or no breathing — they're often mistaken for heroin or fentanyl overdoses. In addition, medical examiners don't always look for xylazine post-mortem.
Researchers say xylazine, which has fully infiltrated the illicit drug supply in Philadelphia — 91% of the illicit fentanyl tested there came back positive for the animal tranquilizer — is making its way west, just like fentanyl did. "We're starting to see it more ... more definitely in Michigan and throughout," said Vohra, who is involved in a study on xylazine.
“It definitely seems to be emerging right now," said Shannon Phillips, epidemiologist at the Washtenaw County Health Department.
There is fear xylazine will push the already record-breaking number of overdoses in Michigan and across the nation further into the stratosphere. Narcan (generic name: naloxone) may reverse an opioid overdose if given in a timely manner. But it only works on opioids. And xylazine is not an opioid.
What to know about this newest threat?
Here are the details:
Why should I care?
If you or someone you love uses street drugs, there is growing likelihood that those drugs — especially fentanyl ― may be laced with xylazine. With more than 107,000 people in the United States dying from drug overdoses last year ― including 3,040 in Michigan ― the presence of xylazine could cause even more people to overdose and/or die.
If the loss of life doesn't faze you, there's this: Drug overdoses cost a lot of money. According to a report by the bipartisan U.S. Commission on Combating Synthetic Opioid Trafficking, overdose deaths cost the nation an estimated $1 trillion a year, including medical costs, police response and loss of productivity.
So what is xylazine?
Also called "tranq," xylazine is a non-opioid animal tranquilizer, often used on horses. It is not approved by the U.S. Food and Drug Administration for human use. Use of the drug is allowed only by licensed veterinarians who use it as a sedative, muscle relaxant and anesthetic for animal surgeries, according to the U.S. Drug Enforcement Administration. "Xylazine is scary," said Friedman, the UCLA researcher who is lead author on a groundbreaking paper on xylazine. “Xylazine is something, unfortunately, I think is becoming increasingly common, that has really serious side effects for humans."
What kind of side effects?
If an overdose doesn't kill you or stop your breathing long enough to cause brain damage or other irreparable harm, there are other complications. Use of xylazine is linked to grotesque skin ulcers that turn into craters of rot. It's "not even a normal abscess," said Friedman, referring to the sores that often accompany intravenous drug use. "This is more like tissue death. This is black, necrotic tissue destruction." And the necrotic tissue doesn't necessarily develop at the site where the drug was injected. There's evidence it can appear anywhere on the body. Because xylazine can knock a person out for hours, it puts users at risk for sexual assault and robbery and other crimes.
David Clayton, who runs HARM:LESS, the Families Against Narcotics' street medicine and harm reduction program, said his team has seen an increase in tissue injuries in metro Detroit. He assumes the injuries are related to xylazine that's being cut into drugs but the only way to know for certain would be to test the drugs at a lab. "Whatever it's cut with, it's causing severe soft tissue wound damage," he said.
How is xylazine added to street drugs?
Veterinarians generally use xylazine in liquid form. But xylazine can can be dried or cooked into a white, crystalline powder that's water-soluble, which means xylazine can be snorted, smoked, injected or swallowed. Since it is most often mixed with fentanyl, which is then mixed with a variety of street drugs ― including heroin and counterfeit pills ― users consume it the same way they consume their illicit fentanyl. If they're shooting fentanyl, they're shooting xylazine. If they're snorting fentanyl, they're snorting xylazine. If they're smoking ... you get the idea.
Do drug users know they're consuming xylazine?
"It's anyone's guess as to whether most users know that it's in (drugs) now," said Vohra. Some are probably consuming it unwittingly, the way heroin users unwittingly consumed fentanyl when dealers first started mixing it into heroin; these days most drug users know that the chances of finding unadulterated heroin is pretty slim. Some drug users may want to consume xylazine, just as some heroin users now want fentanyl in their dope.
Why would someone want xylazine in their drugs?
A fentanyl high is more intense than a heroin high, but it is also relatively short-lived. Drug users ― including those interviewed in a long-term study by Friedman and colleagues ― have told researchers that xylazine extends the feeling of euphoria they get from a fentanyl high.
So it's all about chasing the best high?
Yes ― chasing it and also selling it. Drugs are a business. Dealers want to have the most desirable product on the market. If they believe adding xylazine will make that happen, then they'll add it. For them, it's about money.
How long has xylazine been in street drugs in the U.S?
In 2006, xylazine showed up in the autopsies of seven people who died in Philadelphia. From there, it has only become more commonplace. Between 2015 and 2020, the percentage of drug overdose deaths involving xylazine jumped from 2% to 26% in Pennsylvania, according to Friedman's study. In 2020, xylazine was involved in 10% of Connecticut overdoses. In 2021, it was involved in 19% of overdose deaths in Maryland.
Xylazine has appeared in 91% of the illicit fentanyl samples tested in Philadelphia. And hospital toxicology tests found it present in 78% of people who were also positive for fentanyl.
And now it's moving west.
How widespread is xylazine in Michigan?
It's here. It's in drugs, most often fentanyl, though it has been found in connection with other drugs, too.
Michigan began tracking xylazine in deaths in 2019, according to the Michigan Department of Health and Human Services. Between 2019 and 2021, xylazine was identified in the deaths of 171 people, MDHHS said. Almost all of those deaths also involved an opioid. Some involved an opioid and as well as cocaine. And some involved an opioid as well as methamphetamine. It breaks down this way: Between 2019 and 2020, xylazine-involved deaths among Michigan residents increased 86.8%. However, they appear to have decreased 12.7% between 2020 and 2021, though the 2021 data is preliminary and testing for the drug is inconsistent across the state.
Regionally, xylazine-involved deaths decreased 24.6% in southeast Michigan between 2020 and 2021 and increased 44.4% in southwest Michigan, the MDHHS data show.
But in Washtenaw County, xylazine showed up in toxicology reports of eight ― or 8% ― of the opioid overdose deaths that occurred between Jan. 1, 2021 and May 2022, Phillips said. "Something that particularly stood out to us is that 50% of those ― a relatively small set of cases, given our numbers ― 50% of those came from the start of 2022," she said. Overdoses that involve opioids cut with xylazine have "already surpassed the opioid overdose deaths that involved xylazine in 2021."
Eight percent of opioid deaths involving xylazine doesn't seem like a lot, but it's higher than those analyzed in Friedman's study of drug overdose deaths that involve xylazine. Researchers in that study looked at overdose deaths in 10 jurisdictions ― none in Michigan ― and found xylazine was present in 6.76% percent of those overdose deaths.
But how many people has xylazine actually killed?
That's difficult to determine. Remember: xylazine-involved deaths are undercounted. Vohra knows that xylazine was present in almost 200 deaths but whether it caused those deaths is unclear.
However, researchers continue to study its impact. One study that involved people who died in 2019 with xylazine in their systems showed that xylazine was a cause of death in 64% of those cases.
Is it possible to overdose on fentanyl and be revived but still die from an overdose of xylazine?
Yes. Fentanyl, a synthetic opioid that is up to 50 times more potent than heroin and 100 times more powerful than morphine, is responsible for more overdose deaths than any other drug. These days it takes more Narcan (generic name: naloxone) than ever — often several doses ― to reverse an opioid overdose because fentanyl has so thoroughly infiltrated the street drug market. Xylazine isn't an opioid. So if someone consumes fentanyl that's mixed with xylazine, it is indeed possible their fentanyl overdose may be reversed but they will die from xylazine. There is no antidote for it.
What do you do if someone is overdosing on xylazine?
You give them Narcan because a xylazine overdose looks like a heroin/fentanyl overdose and without toxicology, you can't be sure what kind overdose it is. Also, xylazine is almost always mixed with fentanyl and, said Gina Dahlem, clinical nursing professor at the University of Michigan, "at least naloxone will be effective with the opioid." If naloxone doesn't appear to be working, the overdosing person needs to go to a hospital. "The treatment for xylazine overdoses is to secure the airway, rescue breathing and when you're in the emergency room they will give you fluids or other medications to increase the blood pressure," Dahlem said.
Is there a way to determine whether drugs contain xylazine?
Fentanyl test strips, which can determine in a matter of minutes if drugs are laced with fentanyl. Knowing drugs contain fentanyl allows users to take precautions such as not use alone, have Narcan available, use at a slower pace. But there are no test strips for xylazine. Without extensive lab testing, there's no easy way to tell whether or not it's in the drugs a person is about to use.
Additional sources: National Institute on Drug Abuse; U.S. Drug Enforcement Administration; Michigan Department of Health and Human Services; U.S. Centers for Disease Control and Prevention
This article originally appeared on Detroit Free Press: Xylazine, an animal tranquilizer, is new deadly drug on the street