how often can you take ondansetron

Ondansetron can typically be taken up to 3 times a day for 1 to 2 days after chemotherapy, radiation, or surgery to prevent nausea and vomiting. The usual adult dose is 8 mg every 8 to 12 hours, which means 2 to 3 times daily. In some cases, such as chemotherapy, an initial dosing schedule may include doses every 4 to 6 hours on the first day, but the total daily dose should not exceed 24 mg orally. For certain conditions, taking ondansetron more frequently than prescribed increases the risk of side effects like headache, constipation, or heart-related effects. People with severe liver disease should not exceed 8 mg per day. Always follow the prescribing doctor's instructions for timing and dosage.