Ondansetron is used to prevent nausea and vomiting that is caused by cancer medicines (chemotherapy) or radiation therapy. It is also used to prevent nausea and vomiting that may occur after surgery. Ondansetron works in the stomach to block the signals to the brain that cause nausea and vomiting.
Common side effects
Constipation, Headache, Flushing (sense of warmth in the face, ears, neck and trunk), Injection site reactions (pain, swelling, redness)