TDK conference 2017

Maropitant is a polyamine derivative neurokinin-1 receptor antagonist. Due to its prominent antiemetic effect it is used widely as a treatment of chemotherapy or (other cause?) induced emesis and prevention of motion sickness in dogs. Recent studies have proved that maropitant can reduce the minimal alveolar concentration of sevoflurane during general anesthesia . The purpose of our resarch is to determine the effect of maropitant on the minimal alveolar concentration of isoflurane (the most widely used anesthetic in veterinary practice) by accurate monitoring of the parameters related to the stages of anesthesia. In addition we would like to evaluate the safety and economic benefits brought on by the possibly reduced amount of isoflurane.

Our study took place at the Department and Clinic of Reproduction , University of Veterinary Medicine. In order to create homogenic groups to determine the effect of maropitant ovariectomy was chosen as a standardized surgical intervention. We have monitored the operative anesthesia of 21 healthy female dogs and registered the selected parameters related to the depth of anesthesia (blood pressure, heart rate, respiratory rate, pupil size, eye axis, muscle tone) while reducing progressively the inhalational concentration (v/v%) of isoflurane. Dogs were divided randomly into control and treatment groups. The control group consisted of 10 dogs between the age of 8 month to 7 years (average age: 3,8 years), while there were 11 dogs in treatment group between the age of 7 month to 5 years (average age: 2 years). Before anesthesia all animals were treated with the combination of midazolam + fentanyl + ketamine as premedication, after that we used propofol for induction and morfin for analgesia. All drug dosage calculations were based on the bodyweight of the dogs. In addition animals in treatment group were given 1mg/kg maropitant (antiemetic dose) intravenously. Lenght of observation was between 30 and 100 minutes.

The registered waking of the 10 dogs in control group occured when reaching an average of 1,04 isoflurane v/v%, while treatment group wake-ups occured at reaching 0,55 v/v% in average. According to our results, intravenous administration of 1 mg / kg neurokinin-1 antagonist maropitant has a significant (p<0,05) effect on reducing the minimal alveolar concentration of isoflurane. On the basis of our results, studying the effect of different maropitant doses on isoflurane or other inhalational anesthetics could be rewarding. In case of small breed dogs, the extra expense caused by the use of maropitant can be fully compensated by the reduction of expenses on account of the lower amount of isoflurane required during the procedure.