An antiemetic containing the active ingredient ondansetron, used to prevent and treat nausea and vomiting caused by chemotherapy, radiation therapy, or post-surgical procedures. It works by blocking 5-HT₃ serotonin receptors in the central nervous system and gastrointestinal tract, reducing the sensation of nausea. Dosage should be followed as per the physician's instructions, typically taking a 4 mg tablet before chemotherapy or radiation therapy at a specified time. Store in a cool, dry place, out of reach of children.