Safety Alerts & Recalls

What does this mean?

The Zofran and ondansetron prescribing information already contains information about the potential for abnormal changes in the electrical activity of the heart (QT prolongation) and your doctor will be aware of this risk. The new information on QT prolongation does not change any of the recommended oral dosing regimens for ondansetron products. It also does not change the recommended lower dose intravenous dosing of ondansetron to prevent post-operative nausea and vomiting.

If you take Zofran or one of the generic ondansetron products, do not stop taking your medicine without talking to your doctor or other healthcare provider. Please discuss any questions or concerns about Zofran (ondansetron) with your healthcare professional.

Because Zofran (ondansetron) can cause abnormal changes in the electrical activity, your healthcare provider may occasionally order an electrocardiogram (ECG, EKG) to monitor your heart rate and rhythm. An ECG/EKG is a test that checks for problems with the electrical activity of your heart.

Please seek immediate care if you experience an irregular heartbeat, shortness of breath, dizziness, or fainting while taking Zofran (ondansetron).

Healthcare providers and patients are encouraged to report side effects related to the use of medicines to the FDA's MedWatch Program by telephone at 1-800-332-1088, by fax at 1-800-332-0178, by mail at MedWatch, FDA, 5600 Fishers Lane, Rockville, MD 20852-9787, or on the MedWatch website at

FDA Warns: Abnormal Heart Rhythms May Be Associated with Use of High Dose Zofran (Ondansetron)

The U.S. Food and Drug Administration (FDA) has informed healthcare professionals that early results from a recently completed clinical study suggest that a 32 mg single intravenous dose of ondansetron (Zofran) may affect the electrical activity of the heart (QT interval prolongation), which could increase a patients risk of developing an abnormal and potentially fatal heart rhythm known as Torsades de Pointes. Zofran and its generics (ondansetron) are used to prevent nausea and vomiting caused by cancer chemotherapy, radiation therapy and surgery.

GlaxoSmithKline (GSK) has announced changes to the Zofran drug label to remove the 32 mg single intravenous dose. The updated label will state that ondansetron can continue to be used in adults and children with chemotherapy-induced nausea and vomiting at the lower intravenous dose, a dose of 0.15 mg/kg administered every 4 hours for three doses; however, no single intravenous dose should exceed 16 mg. Information from the new clinical study will be included in the updated drug label.

As part of the ongoing safety review of ondansetron, the FDA continues to assess data about the risk of QT prolongation and will update the public when more information becomes available.

For more information, please visit: more information here

Source: FDA
Publication Date: 2012-07-24
Last Updated: 2012-07-24

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