Medetomidine

Medetomidine
Clinical data
Trade names	Domitor, others
AHFS/Drugs.com	Monograph
License data	US DailyMed: Medetomidine;
Drug class	Alpha-2 adrenergic receptor agonist
ATCvet code	QN05CM91 (WHO) ;
Legal status
Legal status	CA: ℞-only; US: ℞-only;
Identifiers
	IUPAC name (RS)-4-[1-(2,3-Dimethylphenyl)ethyl]-3H-imidazole;
CAS Number	86347-14-0;
PubChem CID	68602;
DrugBank	DB00633;
ChemSpider	61868;
UNII	MR15E85MQM;
KEGG	D08165; D04883;
ChEBI	CHEBI:48552;
ChEMBL	ChEMBL77921;
CompTox Dashboard (EPA)	DTXSID6048258 ;
ECHA InfoCard	100.242.450
Chemical and physical data
Formula	C13H16N2
Molar mass	200.285 g·mol−1
3D model (JSmol)	Interactive image;
Chirality	Racemic mixture
	SMILES n1cc([nH]c1)C(c2c(c(ccc2)C)C)C;
	InChI InChI=1S/C13H16N2/c1-9-5-4-6-12(10(9)2)11(3)13-7-14-8-15-13/h4-8,11H,1-3H3,(H,14,15); Key:CUHVIMMYOGQXCV-UHFFFAOYSA-N;

Medetomidine is a veterinary anesthetic medication with potent sedative effects. As of December 2025, it is an emerging illicit drug adulterant.

It is a racemic mixture of two stereoisomers, levomedetomidine and dexmedetomidine, the latter being the isomer with the pharmacologic effect as an alpha 2- adrenergic agonist. Effects can be reversed using atipamezole.

It was developed by Orion Pharma. It is approved for dogs in the United States, and distributed in the United States by Pfizer Animal Health and by Novartis Animal Health in Canada under the product name Domitor. Starting in 2022 medetomidine has been detected in the US in samples of illicit drugs and associated with overdoses.

The free base form of medetomidine is sold as an antifouling substance for marine paints.