Detomidine is an imidazole derivative and ñ<sub>2</sub>-adrenergic receptor agonist, used as a large animal sedative, primarily used in horses. It is usually available as the salt detomidine hydrochloride. It is a prescription medication available to veterinarians sold under various trade names.
Currently, detomidine is licensed for use only in non-meat horses in the United States, but it is also licensed for use in cattle in Europe and Australia. Detomidine's withholding period is 12âÂÂ72 hours for dairy cattle and 2âÂÂ3 days for meat cattle.
Detomidine is a sedative with analgesic properties. ñ<sub>2</sub>-adrenergic receptor agonists produce dose-dependent sedative and analgesic effects, mediated by activation of ñ<sub>2</sub> 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.
Detomidine is an ñ<sub>2</sub>-adrenergic receptor agonist that binds at a ratio of 260:1 with imidazoline receptor activity.
Detomidine is administered intramuscularly. Oral transmucosal has been investigated and is used in some countries although it has poor bioavailability of around 20âÂÂ25%. Intravaginal administration in the horse and alpaca has induced sedation.
Detomidine administration in sheep activates pulmonary macrophages that damage the endothelium of capillaries and alveolar type I cells. This in turns causes alveolar haemorrhage and oedema causing hypoxaemia.