5-hydroxytryptamine (5-HT3) receptor antagonists (RAs) are a class of antiemetics used to relieve nausea and vomiting associated with chemotherapy. At this time, four 5-HT3 RAs are approved by the Food and Drug Administration (FDA) for use in the United States: ondansetron, granisetron, dolasetron, and palonosetron. Dexamethasone is a corticosteroid. These drugs have been evaluated for use in pediatric patients  to treat acute emesis associated with highly or moderately emetogenic chemotherapy.