A patient on cisplatin therapy develops intractable vomiting on the third day of treatment. The agent of choice for controlling this vomiting is :
Cisplatin-induced vomiting has two phases.

EarlyPhase: It occurs within the first 24 hours. 5 HT3 antagonists like ondansetron are the agents of choice for this condition.
Delayed Phase: Vomiting occurring after 24 hours is less responsive to ondansetron and other drugs. It is best controlled by substance P antagonist like aprepitant.
Aprepitant
Ondansetron
Metoclopramide
Prochlorperazine