5-HT<sub>3</sub> Receptor Antagonists in the Control of Cisplatin-lnduced Delayed Emesis

Two large randomized, double-blind, placebo-controlled studies with an appropriate study design have been conducted to fully evaluate the efficacy of ondansetron in the control of cisplatin-induced delayed emesis. These studies show that ondansetron and particularly ondansetron plus dexamethasone have moderate efficacy in the control of cisplatin-induced delayed emesis and nausea. The benefit of ondansetron, with or without dexamethasone, may be greatest in patients with incomplete control of acute emesis. The efficacy of ondansetron in this setting compared to its greater efficacy during the acute phase of emesis induced by cisplatin and the more prolonged phases of acute emesis induced by cyclophosphamide and carboplatin indicates that non-5-HT3-mediated emetic mechanisms maybe are relatively more important in the delayed phase of emesis following cisplatin.