Antagonism of cisplatin-induced emesis by metoclopramide and dazopride through enhancement of gastric motility.

The antiemetic activity, gastric motor activity, and dopamine receptor effects of metoclopramide, dazopride, and sulpiride were assessed to establish if enhancement of gastric motility or antagonism of central dopamine receptors is the predominant action for drug-induced suppression of cisplatin-induced emesis. Emesis produced in dogs by cisplatin is antagonized by metoclopramide and dazopride. The antiemetic actions of metoclopramide and dazopride are associated with their ability to enhance gastric motor activity. Dazopride, unlike metoclopramide, has minimal dopamine receptor antagonist properties. Sulpiride is a potent dopamine receptor antagonist; however, it had no effect on the stomach and was ineffective in suppressing cisplatin-induced emesis.