A patient undergoing chemotherapy with cisplatin has severe nausea. Which of the following would be the drug to use in this patient

5-HT3 ANTAGONISTS Ondansetron Mech of action:- It blocks the depolarizing action of 5-HT exeed through 5-HT3 receptors on vagal afferents in the g.i.t. as well as in NTS and CTZ. uses:- Cytotoxic drugs/radiation produce nausea and vomiting by causing cellular damage - release of mediators including 5-HT from intestinal mucosa - activation of vagal afferents in the gut -emetogenic impulses to the NTS and CTZ. Ondansetron blocks emetogenic impulses both at their peripheral origin and their central relay. thus, used to control cancer chemotherapy/radiotherapy induced vomiting, and later found to be highly effective in PONV and disease/drug associated vomiting as well. Ref:- kd tripathi; pg num:-668