medetomidine

medetomidine (uncountable)

2. A synthetic drug used in veterinary and human medicine as both a surgical anesthetic and analgesic, molecular formula C₁₃H₁₆N₂; it is also used as an adulterant of street drugs.

   Hypernyms: drug, adulterant < agent < compound, substance

   Coordinate terms: (adulterants) fentanyl (opioid), nitazenes (opioids), xylazine (tranq)

   • 2008 November 12, Sonja B. Hofer, Thomas D. Mrsic-Flogel, Tobias Bonhoeffer, Mark Hübener, “Experience leaves a lasting structural trace in cortical circuits”, in Nature, volume 457, number 7227, →DOI:

     Mice were anaesthetized with a mixture of fentanyl (0.05 mg kg -1 ), midazolam (5.0 mg kg -1 ) and medetomidine (0.5 mg kg -1 ).

   • 2025 December 15, Jan Hoffman, “A Powerful New Drug Is Creating a 'Withdrawal Crisis' in Philadelphia. Medetomidine, a veterinary sedative, mixed into fentanyl has sent thousands to hospitals, not only for overdose but for life-threatening withdrawal. It is spreading to other cities”, in The New York Times‎^[1]:

     A new drug has been saturating the fentanyl supply in Philadelphia and moving to other cities throughout the East and Midwestern United States: medetomidine, a powerful veterinary sedative that causes almost instantaneous blackouts and, if not used every few hours, brings on life-threatening withdrawal symptoms. It has created a new type of drug crisis — one that is occasioned not by overdosing on the drug, but by withdrawing from it. Since the middle of last year, Philadelphia’s hospitals have been strained by patients coming in with what doctors have identified as medetomidine withdrawal. Although the heart rate slows drastically right after use, in withdrawal the opposite occurs: The heart rate and blood pressure become catastrophically high. Patients experience tremors and unstoppable vomiting. Many require intensive care.

   • 2025 December 22, Mattha Busby, “‘It’s made things worse for everyone’: Philadelphia grapples with rise of new street drug. Medetomidine has extreme and fast-acting withdrawal symptoms – and the detox centers that help patients are struggling with how best to cope”, in The Guardian‎^[2]:

     But the mutating illegal drug supply is regularly conjuring new drugs with novel sets of potentially deadly risks. For the past 18 months, there has been a new drug in circulation, the veterinary sedative medetomidine, also known as “rhino tranq”. It has perhaps the most extreme and fast-acting withdrawal symptoms of all known street drugs. […] medetomidine complicates matters because people remain unconscious after the fentanyl overdose has been reversed. “It’s causing havoc on people’s organs,” Pichardo says of the medetomidine, which is causing even younger people to experience organ failure. “Narcan works wonders, but it doesn’t fix organs.” […] By 2021, most “stamps” – small bags of opioid-based drugs which also contain fentanyl, the potent synthetic opioid which remains the leading cause of fatal overdoses in the country – contained xylazine, an even cheaper veterinary sedative also known as “tranq”, which has no approved medicinal uses. After Pennsylvania last year banned xylazine amid a crackdown on the drug, the gangs who control the drug trade replaced it with medetomidine, mostly used as an anaesthetic for dogs but also in intensive care wards (ICUs) to deeply sedate mechanically ventilated patients. By the beginning of this year, medetomidine was present in about seven in 10 stamps. According to the Drug Enforcement Administration, medetomidine is 200 times more potent than xylazine, the flesh-destroying drug which leaves people with bone-exposing wounds on limbs that many people in Kensington have needed to get amputated.