Detomidine is an imidazole derivative and α2-adrenergic agonist, used as a large animal sedative, primarily used in horses. It is usually available as the salt detomidine hydrochloride. Detomidine is a sedative with analgesic properties. α2-adrenergic agonists produce dose-dependent sedative and analgesic effects, mediatated by activation of α2 catecholamine receptors, thus inducing a negative feedback response, reducing production of excitatory neurotransmitters. Due to inhibition of the sympathetic nervous system, detomidine also has cardiac and respiratory effects and an antidiuretic action. Sedation and anaesthetic premedication in horses and other large animals, commonly combined with butorphanol for increased analgesia and depth of sedation. In conjunction with ketamine it may also be used for intravenous anaesthesia of short duration.