The ups and downs of novel antiemetic drugs, part 1: substance P, 5-HT, and the neuropharmacology of vomiting.

ISSUE Novel antiemetic agents such as the newly approved aprepitant (Emend) target receptors for substance P, known as neurokinin-1 (NK(1)) receptors. When NK(1) receptors are blocked in the vomiting center of the brainstem, chemotherapy-induced emesis is reduced. It is possible that blocking NK(1) receptors elsewhere in the CNS will lead to therapeutic actions in depression and other stress-related disorders.