Alpha-2 Agonists as Pain Therapy in Horses

Alpha-2 agonists such as xylazne clonidine romifidine, detomidine medetomidine, and dexmedetomidine, are potent analgesic drugs that also induce physiologic and behavioral changes such as hypertension bradycardia atrioventricular block excessive sedation and ataxia all of which can potentially limit their systemic use as analgesics in some clinical cases The use of medetomidine and dexmetomidine has been introduced for equine anesthesia/analgesia and although not approved in this species, their increased specificity for alpha-2 receptors may offer some potential advantages over the traditional alpha-2 agonists Similarly other routes of administration and benefits of alpha-2 agonists are recognized in the human and laboratory animal literature which may prove useful in the equine patient if validated in the near future This review presents this relevant information.