Key Points

  • Medetomidine, a veterinary alpha-2 adrenergic agonist increasingly found in the fentanyl supply, can cause profound sedation that does not reliably respond to naloxone and withdrawal severe enough to require intensive care.
  • In Philadelphia, medetomidine appeared in 72% of illegal opioid samples in late 2024; xylazine, which had been the dominant adulterant, was detected in only 31% of samples during the same period.
  • A new study of 181 adults in opioid use disorder treatment found that 72% of those using gabapentin outside their prescription had held a gabapentin prescription at some point, and nearly half held one at the time of the study.
  • Gabapentin carries no federal controlled substance classification, but taking it alongside opioids raises the risk of respiratory depression; anyone in treatment should tell their provider exactly how they are taking it.
  • A 2023 global survey found that 16% of countries surveyed reported no access to any opioid agonist medication, while naloxone distribution reached 31% of countries and drug checking only 15%.
  • Three stories, one gap: critical information about what is in a drug supply, a medicine cabinet, or a treatment program does not surface unless someone tests for it or asks.

Addiction News Weekly Episode 1.18

In This Episode

Episode Transcript

Welcome to Addiction News Weekly by Rehab.com, where we break down the biggest stories in addiction recovery and public health.

A New Sedative Is Spreading Through the Fentanyl Supply

This week starts with a research report published in the Annals of Internal Medicine. Researchers at the University of Pittsburgh School of Medicine interviewed 16 adults hospitalized with opioid use disorder between September and November of last year, all with confirmed exposure to medetomidine, a veterinary sedative now turning up in the illicit fentanyl supply.1 The participants described feeling unable to avoid it, because they rarely know what a supply contains.

They described sedation they could not fight off, which left them open to assault and robbery. They also described withdrawal severe enough to put them in a hospital bed. Many said that the standard medications for opioid use disorder did not adequately address what they were going through.1

This is not just one hospital’s problem. New York City’s health department found medetomidine in 32% of samples sold as opioids through its drug-checking program last year, nearly all of them also containing fentanyl.2 In Philadelphia, the CDC reported it in 72% of tested illegal opioid samples in late 2024, while xylazine detection fell from 98% to 31% over the same months.3

Hospitals in affected cities have been rewriting their withdrawal protocols for medetomidine, and clinicians are sharing what works as they learn it. Getting medical care is still the safest and most effective way to manage these situations.

Dr. Sylvie Stacy on Medetomidine Withdrawal

Here is Rehab.com Medical Officer Dr. Sylvie Stacy with her take on this development in the opioid epidemic.

“We’ve seen yet another shift in the unregulated opioid supply, and that is the adulterant medetomidine, which is an alpha-2 adrenergic agonist, much like xylazine, which we’ve been grappling with over the last several years, but medetomidine is significantly more potent. Both of these compounds can really cause heavy sedation, bradycardia, and hypotension, but medetomidine withdrawal is exceptionally severe, and it seems to hit patients faster, and it can present with hemodynamic instability, including dangerous spikes in blood pressure and heart rates that are very high, sometimes 150 beats per minute or so, and that is alongside intractable vomiting and oftentimes muscle jerking. Patients are telling us that standard medications for opioid withdrawal management really don’t seem to touch their withdrawal, and clinical data tells us that as well.

“Managing withdrawal effectively, when it involves both a powerful opioid like fentanyl as well as medetomidine, it appears to be best approached with a scheduled alpha-2 agonist like clonidine and in severe cases, sometimes an ICU-level admission with a continuous dexmedetomidine infusion. And in fact, the authors of this study wrote that ‘the severe, unpredictable, and potentially life-threatening withdrawal from medetomidine cessation has challenged current opioid withdrawal management,’ and they go on to say that ‘abrupt outpatient discontinuation of the contaminated supply may no longer be feasible or safe.'”1

“Unfortunately, I’ve found as a community practitioner that identifying medetomidine and deploying these protocols that are specifically designed to address it, it’s very difficult. Many doctors in methadone clinics and smaller community practices simply don’t have the necessary level of staff or capabilities or equipment and infrastructure to really provide the optimal treatment for patients who are in this situation. And as this study showed, patients are very fearful of severe withdrawal, and they’re fearful that the withdrawal treatment that they’ll receive won’t be effective for them.

“So at this point, what I’m going to do is keep a high index of suspicion. I’m going to watch for withdrawal that fails to respond to standard outpatient protocols. And I’m going to have a somewhat low threshold for sending a patient to the hospital for closer monitoring and possibly for IV treatment.”

Gabapentin in Opioid Treatment: The Prescription Connection

The second story is about gabapentin. Researchers at Washington University in St. Louis and the University of Arkansas, led by Matthew Ellis, recruited 181 adults through 21 opioid use disorder treatment centers across 23 states. The findings were published in the Journal of Addiction Medicine.4

Of those 181 participants, 150 had used gabapentin without a prescription or outside a prescribed dose in the last year. Thirty-one used it only as prescribed. The group using it non-medically scored higher on gabapentin craving, 3.8 against 2.2 on the study’s measure, while opioid craving scores showed no difference between the two groups.

Seventy-two percent of the people using gabapentin non-medically had held a gabapentin prescription at some point. Forty-five percent held one at the time of the study. Only about one in four had never been prescribed it. Gabapentin ranks among the most prescribed medications in the country, carries no federal controlled substance classification, and treatment programs themselves prescribe it for pain, anxiety, and sleep.

The authors note that taking gabapentin alongside opioids raises the risk of respiratory depression. If you are in treatment for opioid use disorder and you hold a gabapentin prescription, say so and say how you are actually taking it. A program watching only for opioid relapse can miss something that is already building.

Where Opioid Treatment Is Available and Where It Is Not

The final story is about what is available and where. A survey published in the International Journal of Drug Policy, run through the International Society of Addiction Medicine’s Global Expert Network, collected reports in 2023 from 42 addiction medicine organizations across 39 countries.5 Methadone was available in 75% of those countries. Buprenorphine in 70%. Sixteen percent reported no access to any opioid agonist medication at all.

A look at harm reduction as a whole shows a similar gap. HIV antiretroviral therapy was available in 95% of countries. Naloxone distribution reached 31%. Drug checking, the service that tells a person what is actually in a supply, reached 15%.

These are expert assessments of national systems, not automated service counts, and the same caution applies at home. A medication can be legal nationwide and still have no prescriber in your county. When you call a program, ask which of the three approved medications it actually offers and whether you leave with naloxone in hand.

Conclusion

Three stories, all with similar gaps. Nobody can identify what is in a drug supply without testing it. Nobody knows what else is in your medicine cabinet unless you say so. And nobody tells you which medications a program stocks unless you ask. The medications and protocols exist. Getting to them runs through a conversation.

If you or someone you love is looking for treatment, Rehab.com lists thousands of verified centers across the country. Free confidential support is available at any time through the SAMHSA National Helpline at 1-800-662-4357. If you are in crisis, you can call or text 988 at any time.

Those are the top stories in the news. For more, visit Rehab.com. We will be back next week. I’m Kay, and thank you for listening.

Sources in This Episode

  1. New York City Department of Health and Mental Hygiene. Drug Checking Program: Medetomidine Detection Data, 2025. Available at: https://www.nyc.gov/site/doh/health/health-topics/drug-checking.page. Accessed September 2026.
  2. Huo S, London K, Murphy L, et al. Notes from the Field: Suspected Medetomidine Withdrawal Syndrome Among Fentanyl-Exposed Patients — Philadelphia, Pennsylvania, September 2024–January 2025. MMWR Morb Mortal Wkly Rep. 2025;74(15):266–268. doi:10.15585/mmwr.mm7415a2. Available at: https://www.cdc.gov/mmwr/volumes/74/wr/mm7415a2.htm
Dr. Sylvie Stacy Written By: Dr. Sylvie Stacy MD, MPH Chief Medical Officer
Sylvie Stacy, MD, MPH, Medical Officer at Rehab.com, is a board-certified addiction medicine specialist with over a decade of experience treating individuals with addictions in diverse clinical settings including residential treatment programs, detox centers, outpatient clinics, and correctional facilities.