By Christine Vestal, Stateline

As a dangerous new additive found in fentanyl and other street drugs surges from coast to coast, health officials in nearly every state are scrambling to track it.  

Xylazine, a large-animal tranquilizer not approved for human use, started showing up routinely in the drug supply in 2019, but didn’t take off until the coronavirus pandemic began in 2020. Also known as tranq, xylazine can give users horrific skin lesions that can result in amputations. It also can cause hourslong blackouts, putting users at risk of theft, rape and exposure to extreme weather. 

Now, local health officials in nearly every state are rushing to keep tabs on where xylazine is showing up and in what quantities. They are trying to alert drug users to steer clear of the toxic additive and educate health professionals and first responders about its devastating effects. 

“They’re using any data they can get their hands on to track xylazine and its complicated set of symptoms and effects on users,” said Richa Ranade, senior director of overdose prevention at the Association of State and Territorial Health Officials. 

In the past two years, the federal Centers for Disease Control and Prevention has published three field reports tracking the spread of xylazine. But so far, there’s no national plan for how to test for the drug and protect drug users. And because the tranquilizer has only been approved for cows, horses and other large animals, medical researchers know very little about its effects on humans and have not identified antidotes.

Lacking federal guidance, Boston, New York City, North Carolina and Rhode Island have developed innovative methods for rapidly testing illicit drug samples, followed by localized messaging to drug users and medical providers about the dangers of xylazine. 

Philadelphia’s health department has published a medical advisory outlining a protocol for xylazine withdrawal management. And Maryland has a pilot project for staffing local harm reduction centers with medical professionals who can treat the horrific wounds the drug is causing. 

Epidemiologists at Brandeis University near Boston are working with state and local health officials and law enforcement to collect samples of the drug supply, test them as quickly as possible and immediately report back to the drug-using community on the prevalence of xylazine.

When temperatures dipped below zero in Boston last week, Traci Green, director of the drug testing project at Brandeis, said she worried that drug users in the city could die from exposure if they inadvertently used fentanyl mixed with xylazine. 

“That’s something we haven’t had to think about before,” she said. “We’ve had a singular focus on fentanyl for a long time and we’ve made a lot of progress preventing overdose deaths. But many of the tools we have aren’t addressing this particular drug.” 

People who overdose after ingesting opioids combined with xylazine should be given naloxone to block the effects of the opioids. But their depressed breathing and heart function may continue because naloxone doesn’t block xylazine, and there’s no known medication that does. 

Similarly, withdrawal from opioids can be managed with buprenorphine and methadone, medications approved by the U.S. Food and Drug Administration. But the agency hasn’t approved any drug for xylazine withdrawal since it is not intended for human consumption. 

Toxicology and law enforcement reports indicate that drug dealers are legally purchasing xylazine online as a cheap heroin and fentanyl filler. Little evidence exists that the tranquilizer is being diverted from veterinary clinics.

Nationwide, the prevalence of xylazine in seizures of illicit drugs by the Drug Enforcement Administration nearly doubled between 2020 and 2021, according to the federal agency. And evidence from individual states indicates it became even more pervasive last year. 

Medical examiners across the country are more frequently detecting xylazine in people who died from drug overdoses. In Vermont, for example, overdose deaths involving xylazine rose from 29 in 2021 to 54 in the first 10 months of 2022. 

But not all coroners and medical examiners test for xylazine, in part because the DEA has not yet listed it as a drug of abuse. As a result, any estimates of its prevalence are grossly undercounted, epidemiologists say.

Rapid Testing

Most often found mixed with fentanyl, xylazine tends to extend the fast-acting opioid’s effects. And although it is not an opioid, it acts on the central nervous system in a similar way, suppressing heart and lung functions. For that reason, medical experts say it’s likely to increase the risk of overdose.

Hardest hit so far have been Connecticut, Maryland, Massachusetts, Pennsylvania, Rhode Island and Vermont, as well as some mid-Atlantic cities, including Philadelphia and New York City, according to the CDC and state and local officials who track the emerging drug threat. 

Western states started seeing smaller amounts of the drug in 2020, while the biggest surge in xylazine between 2020 and 2021 was in the South, according to the DEA.  

In New York City, a new drug testing program launched in 2021 relies on harm reduction and overdose prevention centers to collect drug samples from used syringes and other paraphernalia, as well as drug donations from users, to quickly test for xylazine and get the results back to the community.

If xylazine or any other additive is found, those same harm reduction centers assist in getting the message out to drug users and the local medical community. The person who donated the drug sample is contacted and offered counseling and harm reduction supplies. 

“It’s proven that meeting people where they are and allowing them to come out of the shadows — where a lot of consumption happens — into safe, dignified environments that are also grounded with wraparound services, is life-saving,” New York City Health Commissioner Dr. Ashwin Vasan said in an interview with Stateline.

“Sadly,” Vasan said, “there is no real rapid xylazine testing like fentanyl test strips that we can distribute at bars and clubs” to limit the effect the drug may be having on fatal overdoses. 

But he said the city plans later this year to announce a new overdose prevention program as part of a broader mental health initiative to address what he called the No. 1 public health threat to the city and country and a major driver of premature death and life expectancy.

North Carolina has a similar program based at the University of North Carolina, Chapel Hill, and Rhode Island’s health agency is working with Brown University in Providence on a rapid drug-checking program.

Field test strips for xylazine are under development. They have shown promise but are not yet available.

In the meantime, Matthew Gladden, a behavioral scientist at the CDC’s Injury Center, said the agency recommends that people who use drugs continue administering naloxone to friends who overdose on opioids. If symptoms persist, Gladden said, the agency recommends calling 911 and seeking immediate medical attention. 

Harm Reduction

Xylazine is creating a pernicious new chapter in the nation’s overdose crisis. 

“It’s not just overdose deaths that we have to worry about now,” said Brandeis’ Green, explaining that states and cities will need to develop new ways to address the novel collateral damage xylazine is causing. The blackouts are especially concerning, she said, because the hours-long sedation can leave users vulnerable to rape, injury, robbery and other abuse. 

To reduce potential harm, she said, cities may need to start offering safe public places to temporarily protect drug users who become incapacitated.  

The skin lesions from xylazine can be treated, but they require a different type of treatment than the infections and abscesses medical professionals are used to seeing in drug users. The wrong type of treatment can make the wounds worse. 

Withdrawal management and addiction treatment for xylazine also will have to be explored. 

Like fentanyl in its early years, most drug users avoid xylazine because they’re afraid of the effects of the drug filler. But they have no way of knowing whether it’s in the drugs they’re buying. 

“We’re just now starting to be able to detect whether xylazine is in the drug supply — or not. And in some places, we can determine the percentage it represents. But we still don’t know what dose levels are deadly to humans,” Green said.  

“We’re just now starting to scratch the surface.” 

‘It’s Poison’

Nabarun Dasgupta, senior scientist at the Gillings School of Global Public Health at the University of North Carolina, said he’s encouraged by the drug checking and other harm reduction solutions that states and cities have employed in this xylazine scourge.

“For too long, we’ve waited until people are arrested or dead before we report out new adulterants in the drug supply,” said Dasgupta. But he emphasized that “way more resources” will be needed.

So far, public health officials interviewed by Stateline said they’ve gotten little resistance when asking local sheriffs, the DEA and other law enforcement officials to provide crime lab data and collaborate with them on field testing for xylazine. And state lawmakers are starting to understand what’s at stake, Dasgupta said. 

“Everybody gets it,” he said. “It’s not stigmatized — it’s poison. We see people throw away their drugs if xylazine is found.”

Stateline, an initiative of The Pew Charitable Trusts.