(Second of five parts. Read part one HERE)
BETHLEHEM, Pa. — The drug that has overtaken Philadelphia's illicit street supply first came to the United States less than two decades ago.
Now, "it's to the point that basically everything [the Philadelphia Department of Health] tests is fentanyl and xylazine," said Dr. David T. O'Gurek.
O'Gurek is a vice chairman of Lehigh Valley Health Network's department of family medicine, innovation, equity and wellness.
Xylazine, originally from Puerto Rico, initially was detected by the Philadelphia Department of Health in the illicit drug market in 2006. It is not approved for human use.
From 2017-23, the percentage of drug overdose deaths in Pennsylvania involving xylazine increased from 0% to 24.7%, according to the Drug Overdose Surveillance Interactive Data report.
Preliminary data shows that, of the 3,271 overdose deaths in Pennsylvania in 2024, xylazine contributed to the cause of death in 790 cases, or 24.2%, according to the state Department of Health.
In Lehigh County last year, xylazine contributed to the cause of death in 20 of the 112 overdose deaths, or 17.9 percent.
It's now among the three "biggest abused substances that are misused," in the Lehigh Valley, said Dr. Rachael Westover, medical director of toxicology at St. Luke's University Health Network.
What is xylazine?
Xylazine offers a near-immediate high and lengthens the euphoric effects of opioids, all while cutting costs for dealers.
But experts say the after-effects deliver negative health impacts including high blood pressure, low blood pressure, reduced heart rate, an abnormal heart rate and respiratory depression.
And while the medication naloxone has had tremendous significance in the opioid crisis for its ability to rapidly reverse overdoses, it is ineffective with xylazine.
Heather Noonan was a 31-year-old veterinary technician from Bethlehem and one of the 20 who died with xylazine in her system in Lehigh County in 2024.
Her mother said she didn't know of Noonan's drug use until her death — that she chalked up the difference in her "bright" and "fiery" daughter's behavior to the stress of newfound homeownership.
When paramedics rushed Noonan to the hospital after finding her unresponsive in her car, she had eight breaths per minute, according to her coroner's report. The normal range for an adult is around 12 to 20 breaths per minute.
The U.S. Food and Drug Administration says xylazine also can create "severe, necrotic skin ulcerations" — which Westover said she's seen in the Lehigh Valley, sometimes with devastating effects such as bone exposure and even requiring amputations.
While those symptoms typically are present in users who inject xylazine, the National Institute on Drug Abuse states the drug also can be snorted, swallowed or inhaled.
When it entered the illicit drug supply, it commonly was used in combination with the synthetic opioid fentanyl and referred to as "tranq dope." It's also been found in combination with methamphetamines, cocaine and heroin, officials said.
Its introduction to the illicit drug supply led to a steady takeover in Pennsylvania, officials said.
"For instance, you would see years ago that it was... let's say 80 percent fentanyl to 10 percent xylazine, and then 10 percent some different cut," said Sarah Laurel, founder and executive director of Savage Sisters, a nonprofit harm-reduction organization in Philadelphia.
"And you saw that progressively change, where it was like, 'OK, now we're at 70 percent fentanyl,' and it would kind of go down.
"And now we're at one part fentanyl to the rest being tranquilizer and different adulterants."
How it spread
Xylazine first was approved by the FDA in 1972 for use in animals.
"The drug remains essential for veterinarians who work with horses and other large animals, like cattle and deer," the FDA says.
The FDA and Mayo Clinic note that xylazine "is not approved for human use."
Xylazine made its way into the illicit drug supply through shipments from China, according to the U.S. Drug Enforcement Administration.
Information about the drug was discussed in an Oct. 3, 2024, video and release from the DEA in which officials announced indictments against China-based manufacturing companies and employees.
"DEA has seized xylazine-fentanyl mixtures in 48 of 50 states and in Washington, D.C.," DEA Administrator Anne Milgram said.
"We know where this xylazine comes from — it comes as powder from China and as liquid diverted from veterinary supply chains."
Low cost, lower risk
A joint intelligence report from the DEA and U.S. Justice Department in 2022 said xylazine often could be purchased online from Chinese retailers, oftentimes without association to the veterinary profession.
"A kilogram of xylazine powder can be purchased online from Chinese suppliers with common prices ranging from $6-$20 U.S. dollars per kilogram," the report says.
"At this low price, its use as an adulterant may increase the profit for illicit drug traffickers, as its psychoactive effects allows them to reduce the amount of fentanyl or heroin used in a mixture."
Laurel said bags of tranq dope — xylazine mixed with fentanyl — sold through the illicit drug market used to be $10.
They now range from $3 to $5, Laurel said.
The DEA's laboratory system found that, from 2020-21, the Northeast saw the highest "instances of exhibits involving xylazine," compared with the South, Midwest and Western census regions.
Ultimately, the report says xylazine attracted illicit drug suppliers because of its "low cost and lower risk" nature.
The Shapiro administration didn't classify it as a Schedule III drug until May 2024, which meant anyone transporting xylazine couldn't face "law enforcement scrutiny, as it [was] not a controlled substance," when the report came out.
Now that xylazine is considered a controlled substance, harm-reduction specialists worry its classification could push suppliers to a new cutting agent.
Public health alerts from PA Groundhogs, a statewide drug-checking organization, indicate it already has.
Medetomidine, another animal tranquilizer, appears to be replacing xylazine in the illicit drug supply, with most drug samples showing higher concentrations of medetomidine than xylazine in combination with fentanyl, experts say.
'Supply is changing'
PA Groundhogs on its website describes itself as a "collaborative effort between The Center for Forensic Science Research & Education; Penn State University’s Consortium on Substance Use and Addiction; The Pennsylvania Harm Reduction Network; and Narcomedia.org."
It provides free drug test kits and education services in its Philadelphia and Pittsburgh offices and clinician consulting.
Christopher Moraff, founder of PA Groundhogs and Narcomedia, said the organization captures drug composition "within two weeks of a sample coming in."
Moraff said that "supply is changing."
PA Groundhogs is active in a handful of counties, Moraff said, including Lehigh, but not Northampton.
Still, analyzing drug samples can help understand roughly what areas through which drugs are traveling.
"Supply sources told Narcomedia that the cost of Chinese Xylazine has increased substantially as more states pass laws scheduling the veterinary sedative," the alert said.
"Some suppliers won't ship to North America at all."
Sources reportedly told Narcomedia that xylazine prices have doubled — typical market behavior for adulterated substances once they're classified as scheduled drugs.
Why use xylazine?
The DEA's report suggests that some users intentionally seek out xylazine and some don't.
Westover finds that's common in the Lehigh Valley.
"It's even increased in the number of patients that come in and say they're only using 'tranq,'" Westover said. "I say 'But there's other things in that, too. It's not just xylazine that you're using.'
"But that's what they're buying and that's what they think they're using. But then you'll talk to patients and be like, 'So there's cocaine in your urine,' [and they respond] 'I don't use cocaine.' OK, it's probably in your xylazine then.
"It's kind of hard to keep up with the exact substances that patients are using, but they don't know, either."
It's also hard to determine just how many individuals use xylazine in the region, Westover said.
"I think we're only seeing the people that are actively seeking treatment or they're having these wounds," Westover said. "But I think there's likely a lot more people that are using it than we think."
T.J. Shaughnessy at Lehigh Valley Wound Specialists believes so.
Shaughnessy went to Philadelphia with Project Home and spent a day there with Lehigh Valley Health Network's street medicine team.
"They do have people who are injecting xylazine and fentanyl... but there are more moving parts to it," Shaughnessy said.
He said a lecture that focused on xylazine was part of the Philadelphia trip and addressed questions about why users with wounds avoid medical intervention.
"And so a lot of it, like 54 percent, of the people with wounds who are not seeking medical care, they cited that their reason is because of judgment or 'medical mistreatment by medical staff,'" Shaughnessy said.
"Something like 28 percent had previous bad experience. Some of them have legal concerns, you know, they're nervous to put themselves into the system for fear of detoxing or incarceration or anything like that."
Lengthens high, intensifies damage
While xylazine has been found to lengthen the effects of opioids, "it is not and has not ever been approved for human use," LVHN's O'Gurek said.
O'Gurek, with two other medical professionals, published an editorial piece, "The Role of Xylazine in the Overdose Crisis" in the National Library of Medicine in 2023.
O'Gurek previously worked at Temple University Health System in Philadelphia, so he says he's familiar with usage symptoms, the drug's prevalence and treatment.
Westover said she's seen all of those effects in xylazine users in the Lehigh Valley, too.
'You know what? I can't do this'
Usage can lead to a more severe withdrawal, experts said.
O'Gurek said patients come in with symptoms such as irritability, anxiety and overall feeling poorly, but medications typically used to treat withdrawal or opioid use disorder pose a challenge because of the drug's effects.
"People come in with low heart rates, low blood pressures," O'Gurek said. "We can't give them those medicines, because it's going to make those things worse.
"So it makes it difficult to sort of treat xylazine withdrawal... because it's going to make the person worse and cause worse, lower heart rate or slower respiratory rates, or slower blood pressure.
"Our system doesn't have quite enough knowledge to know what the right thing is."
Sometimes the pain from withdrawal can push patients away.
Westover said she's seen it in patients who come in for a detox or withdrawal management.
"I've had patients who have said, 'You know what? I can't do this. I can't take it anymore. I need to leave,'" Westover said.
"And they'll leave, and they will go use and come back. And we just encourage them to please come back whenever you feel like you're ready for treatment."
What's next?
"The real answer to this would be to create safe supply, because we have centered and focused our funding and our energy on criminalization," Laurel said.
"And we have not even begun testing for xylazine in treatment facilities across the state, nor have we begun treating for the xylazine withdrawal symptoms.
"So all of the funding has not gone into dealing with increasing resources for people consuming xylazine. Instead, it has gone toward criminalization.
"And what you see is the criminal drug market is responding with a new drug that is easier for them to access."
For health care professionals, getting word out about xylazine and adulterated tranquilizers is a top priority.
O'Gurek said that was his driving force for writing about xylazine with his medical peers, especially with the COVID-19 pandemic shifting attention away from other public health crises, such as the opioid crisis.
"The overdose crisis has continued," O'Gurek said. "And it challenges our communities in many ways. So we do need to continue to talk about it, gain greater understanding and address that."
But even getting to that point is a challenge, PA Groundhogs' Moraff said. As a journalist, he said, he finds it difficult to ensure stories have widespread readership.
"That's what's so frustrating for me," Moraff said. "I could tell you about the story I wrote in 2008 and nobody really paid much attention to it.
"I had a picture of a wound in the article, like this was happening already. And it takes time to trickle down.
"And that's why, when we have enough data, we're going to push hard with this clinician awareness program that'll require networking hospitals that are willing to work with us and willing to be educated."
COMING TOMORROW: As more and more synthetic drugs like xylazine gain a foothold, naloxone is no longer the effective antidote it has been amid the opioid crisis.
