Ondansetron (Zofran): QT Prolongation may lead to Fatal Heart Rhythm

Oncology, Surgery, Gastroenterology physicians and patients are informed by the U.S. FDA that, according to a recent study, a 32 mg single intravenous dose of Ondansetron may affect the QT interval prolongation (the electrical activity of the heart) leading to potentially fatal heart rhythm.

Background of Ondansetron (Zofran)

Zofran (Ondansetron), by GlaxoSmithKline, is a serotonin 5-HT3 receptor antagonist used mainly as an antiemetic (to treat nausea and vomiting), often following chemotherapy.

FDA Alert on Ondansetron (Zofran)

According to the preliminary results of recently completed clinical study, a 32 mg single intravenous dose of Ondansetron (Zofran, Ondansetron hydrochloride, and generics) may affect the QT interval prolongation (the electrical activity of the heart) leading to potentially fatal heart rhythm, Torsades de Pointes.

GlaxoSmithKline will remove the 32 mg single intravenous dose from Zofran label. Single intravenous dose should not exceed 16 mg.

FDA Recommendation on Ondansetron (Zofran)

“The new information on QT prolongation does not change any of the recommended oral dosing regimens for ondansetron.  It also does not change the recommended lower dose intravenous dosing of ondansetron to prevent post-operative nausea and vomiting.

• The use of a single 32 mg intravenous dose of ondansetron should be avoided.  New information indicates that QT prolongation occurs in a dose-dependent manner, and specifically at a single intravenous dose of 32 mg.
• Patients who may be at particular risk for QT prolongation with ondansentron are those with congenital long QT syndrome, congestive heart failure, bradyarrhythmias, or patients taking concomitant medications that prolong the QT interval
• Electrolyte abnormalities (e.g., hypokalemia or hypomagnesemia) should be corrected prior to the infusion of ondansetron.
• The lower dose intravenous regimen of 0.15 mg/kg every 4 hours for three doses may be used in adults with chemotherapy-induced nausea and vomiting. However, no single intravenous dose of ondansetron should exceed 16 mg due to the risk of QT prolongation.
• The new information does not change any of the recommended oral dosing regimens for ondansetron, including the single oral dose of 24 mg for chemotherapy induced nausea and vomiting.”

Contacting the FDA to report cases with Ondansetron (Zofran)

In case of detection of adverse events or side effects related to the use of Ondansetron (Zofran), healthcare professionals and patients should report it to the FDA’s MedWatch Safety Information and Adverse Event Reporting program through any of the following ways:

The report can be completed and submitted Online at: www.fda.gov/MedWatch/report.htm

The form can be downloaded or requested by calling 1-800-332-1088, then completed and returned on the address indicated on the form

The completed form can be faxed to:  1-800-FDA-0178

AttorneyOne.com is a free nationwide legal referral service. We are not a law firm. We help consumers find the best representation for their legal needs.