Inhibitory Effects of Maropitant on Morphine-Induced Nausea, Vomiting and PONV in Dogs Undergoing an Ovariohysterectomy

Abstract

Sixty dogs receiving subcutaneous morphine as an analgesic before ovariohysterectomy were divided into four groups of 15 dogs each. Two groups were orally administered maropitant (2 mg/kg in the MP2 group and 8 mg/kg in the MP8 group) 4 hours before induction of anesthesia. Another two groups received subcutaneous maropitant (1 mg/kg, MS1 group) or saline (0.1 ml/kg, control group) 90 minutes before induction of anesthesia. The status of nausea and vomiting were assessed at induction and after extubation. Postoperative nausea and vomiting (PONV) scores were assessed after extubation. Vomiting before induction of anesthesia was significantly reduced in the MP2, MP8, and MS1 groups compared with the control group. Nausea was significantly reduced in the MP8 group (P＜0.05). After extubation, the MP8 group showed significant suppression of nausea and improvement in PONV scores (P＜0.05). The oral administration of maropitant had the same antiemetic effect as subcutaneous administration on morphine-induced vomiting, and oral administration of 8 mg/kg showed sufficient suppressive effects on nausea and PONV.