Aprepitant has been shown in animal models to inhibit emesis induced by cytotoxic chemotherapeutic agents, such as cisplatin, via central actions. Animal and human Positron Emission Tomography (PET) studies with Aprepitant have shown that it crosses the blood brain barrier and occupies brain NK1 receptors. Animal and human studies show that Aprepitant augments the antiemetic activity of the 5-HT3-receptor antagonist ondansetron and the corticosteroid ethasone and inhibits both the acute and delayed phases of cisplatin induced emesis.