Efficacy of different antiemetics with different mechanism of action on xylazine induced emesis in cats

Xylazine hydrochloride, α2 adrenoceptor agonist, is an analgesic, sedative, tranquilizer, and muscle relaxant agent in veterinary medicine which is mostly used as in pre-anesthesia in veterinary medicine. One of the main adverse effects of xylazine which limits application of this medication in small animal veterinary practice (mostly in cats) is nausea and vomiting which can end up with aspiration pneumonia. In this review, we will discuss the efficacy of prophylactic administration of different antiemetics with different mechanism of action in preventing vomiting in cats treated with xylazine hydrochloride. All medications such as acepromazine, promethazine, metoclopramide, ondansetron, dexamethasone, maropitant and vitamine B6 have been shown to have antiemetic efficacy on xylazine induced emesis in cats. These mentioned medications have different antiemetic mechanism of actions. It can be concluded that all these medications not only inhibit α2 adrenoceptor but also may exert their antiemetic effects directly on nucleus tractus solitarius and vomiting center.