Palonosetron (Aloxi): A Second-Generation 5-H[T.Sub.3] Receptor Antagonist for Chemotherapy-Induced Nausea and Vomiting (Pharmacology Notes) (Drug Overview‪)‬

In July 2003, the Food and Drug Administration approved palonosetron hydrochloride injection for the treatment of chemotherapy-induced nausea and vomiting (CINV). The newest agent in the class of 5-H[T.sub.3] receptor antagonists (5-H[T.sub.3]RAs), palonosetron differs from other agents in its class by its higher receptor-binding affinity and longer half-life. These pharmacological properties have resulted in improved antiemetic activity in clinical trials, particularly in the treatment of delayed CINV following moderate emetogenic chemotherapy. Based on the results of these clinical studies, palonosetron is the only 5-H[T.sub.3]RA approved for delayed CINV. Palonosetron is given as a single 0.25-mg intravenous dose 30 minutes before the initial dose of chemotherapy. Headache and constipation were the most common adverse events reported with palonosetron therapy. **********