Critical Clinical Information – Zofran (ondansetron): Drug Safety Communication – Risk of Abnormal Heart Rhythms

by myMatrixx

The FDA’s MedWatch program released new safety information for patient and prescribers of Zofran® (generic-ondansetron). Ondansetron is FDA approved for prevention of cancer chemotherapy-induced nausea and vomiting, prevention of nausea and vomiting associated with radiotherapy, and prevention of postoperative nausea and/or vomiting.

Some recognized off-label uses include, alcohol consumptions/effects, bulimia, cholestatic pruritus, nausea and vomiting in palliative care, tardive dyskinesia, uremic pruritus, and treatment of vomiting associated with N-acetylcysteine use. Ondansetron is often used in pain management for opioid-induced nausea.

Ondansetron may cause a cardiac condition known as QT interval prolongation. This is fundamentally a disruption of normal heart rhythm leading to development of arrhythmias. The most severe form of cardiac arrhythmias is known as Torsade de Pointes which can be fatal.

Patients at increased risk of developing Torsade de Pointes from the use of Zofran® may have existing congenital QT interval prolongation. It is recommended to avoid the use of Zofran® in these patients.

It is recommended to monitor cardiac rhythm (ECG) in patients on Zofran® who have electrolyte abnormalities (e.g., hypokalemia or hypomagnesemia), congestive heart failure, bradyarrhythmias, or in patients taking other medication known to also cause QT prolongation such as: methadone, amiodarone, haloperidol, Abilify®, and others.

Upon learning of this situation, the myMatrixx clinical team began to immediately review our entire client population for patients that are affected. At this point, we are informing all prescribers of Ondansetron and providing sufficient information to identify the level of risk and help guide the selection of suitable alternatives. 

For more information read the FDA MedWatch safety alert, including a link to the Drug Safety Communication here.