The antiemetic effects of domperidone, a novel potent gastrokinetic

Domperidone is the prototype of a new chemical class of compounds with potent gastrokinetic properties. The present study reports on the antiemetic activity and safety of domperidone in dogs. The lowest ED50-values protecting from apomorphine (0.31 mg/kg s.c.) induced emesis are 0.003 mg/kg intravenously, 0.007 mg/kg subcutaneously, 0.03 mg/kg orally and 0.10 mg/kg rectally. Emesis induced by i.v. hydergine, s.c. morphine and oral levodopa is also prevented by low doses of intravenous domperidone, whereas oral copper sulphate-induced emesis is not antagonized. The doses of domperidone needed to induce central depressant effects in dogs (inhibition of conditioned reactions) are at least 300 times higher than the antiemetic doses (apomorphine-induced emesis). Domperidone is also devoid of sedative, adrenolytic and cardiovascular side-effects. The LD50-values in dogs are 42.7 mg/kg intravenously, and more than 160 mg/kg subcutaneously and orally.