Medetomidine Made Quitting Dangerous. Detox Still Ends on Day Five.

Thomas Harris was waiting for a bus under the Market-Frankford elevated in late October, sweating through clothes meant for a colder day, when he tried to explain to a reporter what stopping feels like now. He has used for years. He knows opioid withdrawal the way some people know a bad knee. This is something else. “Excruciating doesn’t even begin to cover it,” he told WHYY’s Andrew McGurl. “Physically, I’ve never felt closer to dying.” Then the sentence that should be pinned above every detox intake desk in the country: “I’m not using to get high anymore.”

He is using so that his heart doesn’t run away from him. The bag he buys in Kensington is sold as fentanyl, and it is fentanyl, mostly. It also carries medetomidine, a veterinary sedative that showed up in roughly 70% of the drug samples Philadelphia’s health department tested in 2025. On Tuesday, the American Society of Addiction Medicine published the country’s first national clinical guidance for it. The guidance is careful, specific, and overdue. It also describes a kind of withdrawal that the detox system, as built, cannot hold.

A five-day opioid detox for a drug that can put you in intensive care is not treatment. It is a waiting room with a discharge date.

The new drug in the bag punishes you for stopping

Here is the plain version of the pharmacology. Medetomidine is a sedative, a cousin of the xylazine that spread through the fentanyl supply a few years ago and roughly as unloved: Hamilton Morris, the researcher and chemist, told WHYY that it “does not create a pleasurable experience in any way.” It works by turning down the body’s alarm system, the part of the nervous system that raises your heart rate and blood pressure when you’re scared or in danger. Use it every day and the body compensates by turning that alarm system up. Stop suddenly and the alarm screams with nothing holding it down. Clinicians call this autonomic hyperactivity; you would call it your heart pounding at a rate you can feel in your teeth while your blood pressure climbs toward stroke territory.

The numbers from the hospitals that have seen it are not subtle. When Pittsburgh doctors wrote up ten confirmed cases for the CDC, nine of the ten patients went to the ICU, the median peak heart rate was 165 beats per minute, and the median peak systolic blood pressure was 200. One man in that report, 36 years old, came to the emergency department for what he thought was ordinary opioid withdrawal. Within three hours his heart rate hit 163; when doctors tried to put him on a ventilator, his heart stopped and they had to shock it back. He went home on day eight. A larger study of 209 patients across three Philadelphia hospital systems, led by Kory London and published in the Journal of Addiction Medicine, found 78% needed intensive care, 20% were intubated, and a third left the hospital before doctors considered them ready. That last number is the one to sit with. A third of people walked out. Some of them, almost certainly, walked out to the corner, because the corner was the only place that could make the pounding stop.

This is the part of the story that the word “adulterant” hides. For most of the history of the fentanyl era, the brutal logic of withdrawal pointed in a recognizable direction: it was miserable, it drove people back to use, and it was rarely, by itself, what killed them. Medetomidine reverses that. Stopping is now physically dangerous in a way that a decade of public messaging about “getting sick” never prepared anyone for. Dominic Cipriano, who started using medetomidine-laced dope in Kensington in the spring of 2025, told the Inquirer: “We don’t want to do this stuff. But we’re so scared to stop.” If you have ever been told you just need to want it badly enough, notice what Cipriano is describing. He wanted it. His body had been rewired to punish the wanting.

Dominic Cipriano, who started using medetomidine-laced dope in Kensington in the spring of 2025, told the Inquirer: “We don’t want to do this stuff.

The psychology follows the physiology. People in withdrawal who believe, correctly, that stopping might kill them make rational decisions inside an irrational situation. They taper on the street. Harris has cut from eight to ten bags a day down to five or six, weaning himself because nobody in a hospital would. That is not denial or “not being ready.” It is a person running his own detox protocol because the official one doesn’t fit the drug in his veins.

The guidance is good. The system it lands in is built for a different drug.

ASAM’s Clinical Considerations on Medetomidine Intoxication and Withdrawal does the things a clinical document should. It tells clinicians to tell intoxication from withdrawal by the heart rate: medetomidine on board slows the heart and sedates; withdrawal speeds it and spikes blood pressure. It tells them to give naloxone in small, repeated doses until breathing comes back, because the fentanyl in the bag still responds to it even though the sedative does not. It recommends the drug class that calms the alarm system, alpha-2 agonists such as clonidine and, in severe cases, IV dexmedetomidine, which is the hospital-grade version of the same molecule, and it warns that severe cases may need much higher doses than anyone is used to. ASAM president Stephen Taylor put it plainly: “Medetomidine withdrawal can be debilitating and life-threatening.” Coauthor Jeanmarie Perrone, who founded Penn’s Center for Addiction Medicine and Policy, said it “demands a more intensive clinical response than typical opioid withdrawal.”

Then comes the line that matters most and will be read least: the guidance says moderate-to-severe cases often need hospital care, potentially in an ICU, that people stabilized there can step down to medically monitored residential care, ASAM Level 3.7, for medication management and vital-sign checks, and that Medicare, Medicaid, and other payers should cover Level 3.7. “Should” is doing heroic work in that sentence. Level 3.7 beds are scarce in most states, and the reimbursement for them was built around a few days of opioid withdrawal management, not a week or more of titrating blood-pressure medications in someone whose heart rate can swing 60 beats in an afternoon.

Harris described the gap in seven words: “They treat you for opioids, not medetomidine.” And: “The last time I ended up in the hospital, nobody would give me Precedex,” the brand name for dexmedetomidine. Jamaal Shaban, a surgeon who works with Philadelphia harm-reduction groups, told WHYY that “detox can’t be a five-day event; it has to be at least two weeks now.” Perrone named the next wall: “People can’t get on dexmedetomidine for the rest of their lives.” There is no long-term medication for medetomidine dependence. There is no buprenorphine for this. The clinical playbook is a bridge, and the far bank isn’t built yet.

There is also a diagnostic hole. Standard hospital drug screens do not detect medetomidine, and there is no rapid bedside test. The CDC’s April health advisory told clinicians to suspect it when sedation persists after enough naloxone, and ASAM tells them to lean on local public-health drug-checking data. That means the quality of your care in withdrawal now depends partly on whether your city runs a drug-checking program and whether the ER doctor in front of you reads its bulletins. That is a strange thing to make survival depend on.

If you run or staff a withdrawal-management program, this week’s work is concrete. Put heart rate and blood pressure thresholds for suspected medetomidine withdrawal into your intake protocol, using ASAM’s example protocols as the starting draft. Find out today which hospital in your referral network will start dexmedetomidine and has ICU capacity to do it, and write that name on the whiteboard. Pull your Level 3.7 contracts and see whether your payers will authorize stays long enough for an alpha-2 taper; if they won’t, the ASAM document is the citation for your appeal. And ask your county health department for its most recent drug-checking results, because you cannot treat a drug you don’t know is there.

Find out today which hospital in your referral network will start dexmedetomidine and has ICU capacity to do it, and write that name on the whiteboard.

This is not Philadelphia’s problem for long

It is tempting to read this as a Northeast story. The data says don’t. Law-enforcement lab reports of medetomidine rose from 247 in 2023 to 2,616 in 2024 to 8,233 in 2025, according to the CDC advisory. In the CDC’s sentinel network, half of the 20 sites detected it, at about 35% of opioid-positive samples in the second half of 2025, and every one of the five Western sites detected it at lower levels, between 2% and 8%. Of the drug samples that tested positive for it, 98% also contained fentanyl. As of this Monday, the CDC’s emerging-drugs summary still describes it the same way: present in the illegal supply, mostly mixed with fentanyl.

Two to eight percent is where Philadelphia was before it was 70%. Alex Krotulski of the Center for Forensic Science Research and Education told the Inquirer that “medetomidine’s proliferation across the U.S. has been a lot faster than xylazine.” For anyone watching from Phoenix, Tucson, or Albuquerque, that is the sentence. You can follow the low-level detections on our novel and emerging substances page, and if the pattern of fentanyl getting stranger feels familiar, it’s because we tracked the same shape earlier this year when carfentanil resurfaced in the supply.

Why did this happen? The most honest answer in the WHYY piece came from a DEA official. Joshua Romig, assistant special agent in charge in Philadelphia, described the switch from xylazine to medetomidine as “straight economics”. Pennsylvania moved xylazine to Schedule III in 2024. Medetomidine is effective at far smaller doses and easier to move. The supply adapted, as supplies do. Perrone said it directly: “Scheduling will always cause the emergence of new drugs.”

We have watched this happen before, and the first time, the government did it on purpose. In 1926, frustrated that Americans kept drinking through Prohibition, the federal government ordered industrial alcohol laced with more and deadlier poisons, betting that the threat of death would deter the thirsty. It did not. Over Christmas 1926, Bellevue Hospital in New York counted eight dead by Christmas Eve and 23 more over the next two days. The city’s chief medical examiner, Charles Norris, called the policy “our national experiment in extermination,” and noted that it killed the poor, who drank the cheap stuff, and spared everyone else. By the end of Prohibition some estimates put the toll at 10,000, as Deborah Blum documented in Slate. Nobody is deliberately poisoning the fentanyl supply today. But the mechanism rhymes: pressure on one substance pushes the market toward something stranger, the people with the least choice absorb the consequences, and the medical system finds out from the morgue and the ICU.

The country only got its first-ever “emerging threat” designation for an adulterant in April 2023, for xylazine, two years after it had already transformed Philadelphia’s streets. The Inquirer reported that it took about nine months from first identifying medetomidine withdrawal to official city treatment guidance, and national guidance arrived this week, more than two years after it entered the supply. Danny Teixeira da Silva of Philadelphia’s health department called local adoption “the fastest I’ve seen evidence change clinical practice.” He’s right, and it was still slower than the drug.

What still works tonight, and the door that’s open

If medetomidine is in your supply or might be, some things have not changed, and they are still yours. Naloxone still reverses the fentanyl, which is in almost every bag that carries medetomidine; the CDC says to give it, repeat it every two to three minutes if breathing doesn’t come back, and call 911, even if the person stays drowsy afterward. That drowsiness is the sedative, which naloxone can’t touch; it does not mean the naloxone failed. If you are trying to stop and your heart is racing, you have chest pain, you can’t stop vomiting, or you’re drifting in and out, the CDC tells the public to go to the emergency room. That’s not overreacting. Poison Control at 1-800-222-1222 will talk to you or the ER doctor about it. And if you are planning to stop, tell whoever is helping you about medetomidine by name, and ask whether they will start an alpha-2 medication early, before the alarm system is screaming, not after. The guidance is on your side now. Bring it to the intake desk. You can find programs near you through Rize’s treatment search and our treatment and recovery coverage.

Poison Control at 1-800-222-1222 will talk to you or the ER doctor about it.

There is a second story in the Inquirer’s reporting that deserves the last word. Cipriano’s half-sister, Diamond Stahl, has been in recovery for three years and works as a certified recovery specialist at Penn Medicine. She once texted her brother three words: “Please don’t die.” He eventually landed at Penn Presbyterian, got the combination of medications that actually matched his withdrawal, including dexmedetomidine, and asked paramedics to take him to inpatient rehab. “They spent extra time with me, connected with me,” he said. “I started to think differently.” What got him through was not willpower. It was the right medicine for the actual drug, given by people who believed his withdrawal was as bad as he said it was.

That is the whole fight in one hospital bed. Thomas Harris is tapering himself on the street because the system offered him five days of treatment for the wrong drug. Dominic Cipriano got through because, for once, someone treated the drug that was actually in him. The difference between those two men is not character. It’s whether the detox unit read this week’s guidance.