What is Zofran?

Zofran is approved by the Food and Drug Administration (FDA) to prevent nausea and vomiting caused by chemotherapy and radiation therapy. The drug is also used to treat nausea and vomiting after surgery.

Zofran is sometimes used off-label to prevent morning sickness during pregnancy, though this use has been linked to birth defects.

How does Zofran Work?

Zofran is manufactured by GlaxoSmithKline. The active ingredient in Zofran, ondansetron, is available through more than a dozen other drug makers. The medication belongs to a class of drugs called 5-HT3 antagonists. These drugs work to prevent the sensation of nausea by blocking the natural chemical serotonin, which is believed to trigger nausea and vomiting.

What is Off-Label Use?

Before a drug can be approved for a particular use, a drug company must submit clinical data and other information to the FDA for review that shows that the drug is safe and effective for the intended use. “Safe” does not mean the drug doesn’t have any side effects. It means the FDA has determined the benefits of using the drug for a particular use outweighs the potential risks.

Once a medication has been approved, health care providers generally can prescribe the drug for uses other than those approved by the FDA if they judge that it is medically appropriate for their patient. However, drug companies cannot promote a medication for off-label use.

Between 2002 and 2004, Zofran manufacturer GlaxoSmithKline began promoting Zofran as an off-label treatment for morning sickness despite the fact that the drug was never approved for this use and that there have been no well-controlled studies in pregnant women.

In 2012, the U.S. Department of Justice accused GlaxoSmithKline of marketing Zofran and other drugs for off-label uses. The drug company agreed to pay $3 billion to the U.S. government and certain states for these and other violations. More than $2 million was allocated to Zofran and about $55 million for kickbacks for nine drugs, including Zofran.

Zofran Side Effects

Common side effects of Zofran include:

  • Constipation
  • Diarrhea
  • Drowsiness
  • Fever
  • Head pain

In 2011 and 2012, the FDA issued a Safety Communication that people treated with Zofran were at risk of developing abnormal changes in the electrical activity of the heart, called prolongation of the QT interval of the electrocardiogram, which can lead to abnormal and potentially fatal heart rhythms including Torsade de Pointes.

A growing number of epidemiological studies have linked Zofran use during pregnancy to an increased risk of congenital birth defects such as cleft palate and septal heart defects.

Zofran Birth Defects

In 2012, a study conducted at the Sloan Epidemiology Center involving more than 9,000 pregnant women, found that women who were treated with Zofran during their first trimester had twice the risk of delivering a baby with a cleft palate.

A second study conducted by researchers in Denmark involving more than 900,000 births from 1997 to 2010 found that pregnant women treated with Zofran during the first trimester were twice as likely to give birth to a baby with a serious congenital heart condition.

Zofran’s potential effects on fetal development was studied again in 2014, this time by Swedish public health officials and researchers. Researchers concluded that babies exposed to Zofran during the first trimester were 1.62 times more likely to be born with congenital heart defects, specifically cardiac septum defects, which includes atrial septal defects, ventricular septal defects, and atrioventricular septal defects.

In November 2013, the journal BioMed Research International published a study during which Australian researchers found a 20 percent increased risk of a major birth defect and a 7-fold increased risk for kidney malfunctions among babies exposed to Zofran during the first trimester. Researchers reported that they could not conclude whether Zofran was safe to use during pregnancy due to the small size of the study. However, they did find “an increased risk of a major birth defect, preterm birth, shorter birth length, and maternal urinary tract infection.”

Zofran Lawsuit

More than 500 Zofran lawsuits have been consolidated into a multidistrict litigation (MDL) in the U.S. District Court of Massachusetts. Discovery proceedings began in 2016. To date, no trial dates have been scheduled.

Plaintiffs in the Zofran MDL accuse GlaxoSmithKline of unlawfully promoting Zofran for off-label use during pregnancy, hiding evidence that Zofran can increase the risk for congenital birth defects, and failing to warn the public of Zofran side effects.

Zofran Lawyer

Women who were treated with Zofran during pregnancy and delivered babies with birth defects have filed lawsuits against the manufacturer of the drug. If your child suffers from a birth defect that may have been caused by maternal use of Zofran, you may have a claim against the manufacturers. Please contact us today by filling out the brief questionnaire or by calling our toll-free number (1-800-898-2034) for a free, no-cost, no-obligation evaluation of your case


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