Palonosetron is a new generation 5-HT3 antagonist and It has hasgreater receptor-binding properties, which results in a much longer half-life than the previously described drugs. This selective and conformationally restricted 5-HT3 receptor antagonist was approved for the treatment of chemotherapy-induced nausea and vomiting. The drug was originally developed by Syntex Corp (now Roche Bioscience) and is currently being developed by Helsinn and MGI Pharm.