Zofran is used to treat nausea or vomiting that may be caused by surgery or by cancer drug treatment and radiation therapy. It is also used to prevent and treat nausea and vomiting after surgery. It works by blocking one of the body’s natural substances, serotonin, that cause vomiting.


Common side effects include headache, dizziness, drowsiness, tiredness, or constipation. Unlikely side effects also include stomach pain, muscle spasm, or vision changes. In rare cases it may cause a condition that affects the heart rhythm, called QT prolongation.


The FDA issued a Drug Safety Communication alerting the medical community to the risk of abnormal heart rhythm associated with Zofran. If untreated, QT prolongation leads to ventricular defibrillation, which can lead to permanent brain damage or death.