Josh Trebach, MD
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jtrebach.bsky.social
Josh Trebach, MD
@jtrebach.bsky.social
ER doc. Toxicologist. 🏳️‍🌈 I post about poisons & cats & fighting misinformation. Posts/DMs = my own (not employer’s) & not medical advice. contact = [email protected]
I’m the lucky one ;)
January 23, 2026 at 5:57 PM
You might be on to something
January 23, 2026 at 5:57 PM
I still remember some codes
January 23, 2026 at 5:44 PM
I'll wrap this up here so I don't keep rambling--thanks for reading everyone.

If you are concerned about yourself/someone, please call 911/go to the nearest hospital (pls do not dm/email me asking for medical advice).
December 15, 2025 at 10:51 PM
(cont.) Good supportive care is key. Acute withdrawal from the opioids should be managed the same way you would normally manage opioid withdrawal (ie, meds like buprenorphine). Medetomidine withdrawal may require introduction of alpha 2 agonists like clonidine to help manage.
December 15, 2025 at 10:51 PM
HOW DO CLINICIANS TREAT WITHDRAWAL FROM OPIOID/MEDETOMIDINE?

I recommend consulting with tox/poison center/addiction medicine. There's good data on opioid withdrawal treatment, but medetomidine withdrawal has less data and would benefit from expert involvement (see next tweet)
December 15, 2025 at 10:51 PM
CAN YOU WITHDRAW FROM BOTH OPIOIDS & MEDETOMIDINE?

People can withdraw from opioids which can be incredibly awful to go through. One can withdraw from medetomidine as well and experience effects like tachycardia and encephalopathy. Going through both withdrawals would be awful
December 15, 2025 at 10:51 PM
TREATMENT FOR OPIOID/MEDETOMIDINE TOXICITY?

For clinicians, treatment = supportive (protect airway, address hypotension with fluids & pressors if needed, etc), give naloxone if concern for opioid toxidrome present/respiratory depression. Calling poison control/tox is recommended
December 15, 2025 at 10:51 PM
WHAT HAPPENS WHEN SOMEONE USES OPIOIDS + MEDETOMIDINE?

Medetomidine = sedation, bradycardias, hypotension. Some data show hallucinations. Opioids = sedation, bradycardias, hypotension, and life-threatening respiratory depression. Together these are a dangerous combination
December 15, 2025 at 10:51 PM
CAN YOU TEST SOMEONE FOR MEDETOMIDINE?

Yeah you can do testing to look for medetomidine/metabolite of medetomidine but it’s certainly not a routine test that is quickly done. Usually it would be a test that a hospital would have to send out to specific lab.
December 15, 2025 at 10:51 PM
WOULD SOMEONE KNOW IF THEIR OPIOIDS HAS MEDETOMIDINE IN IT?

There’s no data (to my knowledge) that says medetomidine has a certain taste/smell/appearance. People may feel their normal opioid hit them harder (or cause hallucinations?) and it may lead to a new withdrawal state
December 15, 2025 at 10:51 PM
WHY IS MEDETOMIDINE IN THE ILLICIT OPIOID SUPPLY?

Not entirely clear, but possibly bc it can be used to mimic sedative effects of opioids (e.g., fentanyl) while reducing cost for suppliers. There's also market/cost factors $$$$$. Also its high potency may make it appealing
December 15, 2025 at 10:51 PM
SO DOES THE LEVOMEDETOMIDINE DO ANYTHING?

Short version: eh
Long version: the data we have shows that it doesn’t seem to be cause any effects in dogs/rats at decent dosing; however, there may be some human cell/receptor interactions in some data (PMID 9584224)?
December 15, 2025 at 10:51 PM
WAIT ISN’T DEXMEDETOMIDINE A HUMAN DRUG?

Ya there’s a drug called Precedex (dexmedetomidine) that is used in humans for sedation. It does not contain levomedetomidine.
December 15, 2025 at 10:51 PM
WHAT IS MEDETOMIDINE?

Medetomidine is a veterinary anesthetic medication. It’s composed of two different types of molecules called enantiomers: dexmedetomidine and levomedetomidine. The dexmedetomidine is the active component and is an alpha 2 adrenergic agonist.
December 15, 2025 at 10:51 PM