FDA and Drugmaker Warnings About Zofran® for Patients and Prescribers

Anti-nausea medications can be lifesaving for patients undergoing chemotherapy and recovering from invasive surgeries. One of these medications, Zofran®, is well-known for its ability to control nausea and vomiting. However, the medication may not help a large number of patients—and in some cases, the drug can worsen medical conditions and lengthen recovery times.pills spilling out of a bottle

Zofran Warnings from the Manufacturer

Zofran and its generic form, ondansetron, are both prescribed to thousands of patients every day. Zofran’s developer, GlaxoSmithKline, has warned that some patients will benefit more from Zofran than others. Patients should be warned of the known dangers of Zofran, including:

  • Masking medical conditions. Zofran works by blocking the body’s natural vomiting response to nausea. Although this can encourage eating, it can also prevent the body from vomiting due to an underlying medical condition. Patients taking Zofran after abdominal surgery may not show symptoms of stomach distension or other complications because Zofran can block the early warning signs of complications.
  • Different absorption rates. Studies conducted by the drug manufacturer showed that ondansetron was absorbed more quickly in women than men. Women also took longer to clear the drugs from their systems and showed higher blood plasma levels of ondansetron than men.
  • Using apomorphine with Zofran. Patients who take apomorphine for the treatment of Parkinson’s disease or as a way to induce vomiting have suffered dangerously low blood pressure and loss of consciousness when taking Zofran.
  • Pregnancy risks. Although the manufacturer performed reproduction studies by administering ondansetron to pregnant rats and rabbits, no controlled studies have been performed on pregnant women. As a result, the company maintains that while there is no evidence of harm to a developing fetus, it warns that women should not use Zofran during pregnancy unless absolutely necessary. 
  • Sensitivity issues. Patients who have shown signs of hypersensitivity to other 5-HT3 receptor antagonists may suffer reactions to Zofran tablets, Zofran ODT®, and Zofran IV solutions.

FDA Warns About the Cardiac Dangers of Zofran

Shortly after Zofran’s release, the U.S. Food and Drug Administration (FDA) ordered GlaxoSmithKline to conduct a study to address the risk of adverse heart events in patients. When the results showed that heart risks were directly tied to the dose of Zofran, the FDA moved to protect patients from receiving large single-doses of the medication.

In 2012, the FDA issued a drug safety communication warning that the 32 mg single intravenous (IV) dose of Zofran (ondansetron hydrochloride) can cause an irregular heart rhythm called QT interval prolongation. This condition may lead to an abnormal and life-threatening heart rhythm known as Torsades de pointes. Doctors were advised only to administer single IV doses in 16 mg or fewer, regardless of the patient’s weight or height. The potential for prolonged QT interval would be greater; therefore, no single intravenous dose should exceed 16 mg. The FDA also notified health care professionals that the 32 mg IV doses of Zofran will be discontinued, and that all manufacturers of 32 mg dose ondansetron products should voluntarily recall that product.

The FDA advises patients to take the following actions when starting or using Zofran for nausea:

  • Always inform your prescribing doctor about your questions or concerns.
  • Ask your doctor if you need an electrocardiogram during your treatment to monitor your heart rate and rhythm.
  • Seek immediate medical intervention if you experience heart flutters, shortness of breath, dizziness, loss of consciousness, or other side effects of an irregular heartbeat while taking ondansetron.
  • Report the side effects that you experience to the FDA MedWatch program to alert officials of potential dangers to patients.

If you or someone you love was injured as a result of taking Zofran during pregnancy, the McGartland Law Firm can help you recover. We have won millions in settlements for patients injured by dangerous drugs, and we do not collect any legal fees unless we win your case. Contact us today using our or by calling the number on this page.