FDA Date: 9/14/11
Zofran Oral FDA Drug Safety Communication
Abnormal heart rhythms may be associated with use of Zofran (ondansetron)
FDA is informing the public of an ongoing safety review of the anti-nausea drug Zofran (ondansetron, ondansetron hydrochloride and their generics). Ondansetron may increase the risk of developing abnormal changes in the electrical activity of the heart, which can result in a potentially fatal abnormal heart rhythm.
FDA has reviewed all available information and is making interim changes to the drug labels. The manufacturer of Zofran (GlaxoSmithKline) is being required to conduct a thorough QT study to assess the potential for the drug to prolong the QT interval. The results from this study are expected to be available in the summer of 2012. Additional label changes may result after the additional information has been reviewed.
The Zofran (ondansetron) drug labels already contain information about the potential for QT prolongation. The labels are being revised to include a warning to avoid use in patients with congenital long QT syndrome, because these patients are at particular risk for Torsade. Additionally, recommendations for ECG monitoring in patients with electrolyte abnormalities (e.g., hypokalemia or hypomagnesemia), congestive heart failure, bradyarrhythmias, or in patients taking other medications that can lead to QT prolongation, are being included in the labels.
- ECG changes including QT interval prolongation have been seen in patients receiving Zofran (ondansetron). In addition, Torsade de Pointes, an abnormal heart rhythm, has been reported in some patients receiving ondansetron.
- The use of Zofran (ondansetron) should be avoided in patients with congenital long QT syndrome.
- ECG monitoring is recommended in patients with electrolyte abnormalities (e.g., hypokalemia or hypomagnesemia), congestive heart failure, bradyarrhythmias, or patients taking concomitant medications that prolong the QT interval.
- Advise patients to contact a healthcare professional immediately if they experience signs and symptoms of an abnormal heart rate or rhythm while taking Zofran (ondansetron).