Introduction to the clinical pharmacology of medetomidine

Medetomidine is a sedative and analgesic drug intended for use in dogs and cats but it can also be successfully used in many other species. The effect of medetomidine is dose dependent at the recommended dose range (10-80 micrograms/kg for dogs and 50-150 micrograms/kg for cats). At doses higher than the recommended ones the strength of sedation does not increase, only the duration of the effect. From the cardiovascular changes induced with medetomidine, the profound bradycardia is most prominent. It can be transiently prevented with atropine or glycopyrrolate medication. An initial increase in arterial blood pressure followed by a longer lasting slightly hypotensive or normotensive period can be observed. Respiratory frequency tends to decrease but the changes stay within normal limits for resting animals. Vomiting may occur during the induction period of sedation. Occasional muscle jerks can be observed. Hypothermia has been reported in every animal sedated with medetomidine. Medetomidine can be used as preanaesthetic prior to ketamine, barbiturate and halothane anaesthesia.