JEDAN-4 contains Ondansetron 4 mg in an orally disintegrating tablet (ODT) formulation. It is an antiemetic medicine used to help prevent and control nausea and vomiting associated with certain medical treatments or conditions. Ondansetron works by blocking serotonin (5-HT3) receptors involved in triggering nausea and vomiting. The tablet is designed to disintegrate in the mouth. Use this medicine as directed by a qualified healthcare professional, especially if you have a heart rhythm disorder or take other medicines that may affect heart rhythm.