Zofran, a drug classified as a 5-HT3 receptor antagonist, is given orally or by injection to treat chemotherapy-related nausea. However, manufacturer GlaxoSmithKline has pushed it on multiple occasions as an off-label treatment for extreme morning sickness, a condition known as hyperemesis gravidarum. While off-label marketing is illegal and GlaxoSmithKline faced a DOJ lawsuit regarding this practice in 2012, Zofran has been associated with birth defects and adversely affecting heart conditions.


Since 1992, GlaxoSmithKline allegedly has received hundreds of reports correlating Zofran exposure with birth defects.

The FDA, however, didn’t issue a warning until 2011. The organization’s Drug Safety Communication statement claimed that ondansetron, the generic version, is associated with developing an abnormal heart rhythm, including QT internal prolongation and Torsade de Pointes. The FDA further advised that doctors should not prescribe this drug to patients with QT syndrome, and that GlaxoSmithKline is required to conduct a study determining the medication’s risks.

By February 2013, a study published in the New England Journal of Medicine appeared, stating no correlation between Zofran usage and birth defects exists. However, results from a study from The Center for Birth Defects Research and Prevention contracted these findings. This second study used the same data but from a greater period of time; at the International Society of Pharmacoepidemiology, researchers revealed that infants exposed have double the risk of birth defects. As well, the study compared Zofran with metoclopramide, and discovered that the latter medication did not increase infants’ risk.

Also in February 2013, it was discovered that pregnant women already using an SSRI may develop serotonin syndrome after taking Zofran. The potentially-fatal condition alters the amount of serotonin in a patient’s brain. By this time, 39 reports supporting this association had been filed.

More findings followed in 2014. A study using data from the Swedish Medical Birth Register found Zofran exposure during the first trimester doubles a child’s risk for developing a cleft palate, cardiovascular defects, and a cardiac septum defect.

In early 2015, Canadian newspaper The Star published its own study, which involved examining the FDA’s database from 2010 to 2013. During this period, 20 Canadian women had children with birth defects, including two that led to death. Other infants faced kidney and heart problems, musculoskeletal anomaly, mouth deformity, jaundice, or a heart murmur, or were born underweight as a result of a condition known as “fetal growth restriction.”

By January 2015, the FDA issued a second warning, one stemming from a clinical study showing that a 32mg intravenous dosage may affect the patient’s electrical activity of the heart. As a result, GlaxoSmithKline announced it would change the drug label.

Following, Pediatric Emergency Care found that Zofran may have fatal side effects when given to children. The findings come after two children – one 10 years old and another 86 days old, both suffering from gastroenteritis – were admitted to the emergency room and given one or more doses of Zofran. Both developed tachycardia, a condition characterized by a faster-than-average heart rate.


GlaxoSmithKline first faced a lawsuit concerning its marketing practices in 2012. The Department of Justice required the manufacturer pay a $1 billion settlement concerning its illegal off-label marketing practices.

More recently, two product liability lawsuits were filed against the company. The plaintiffs allege their children had been born with serious heart-related birth defects and developmental delays resulting in multiple surgeries. Both had been given Zofran to treat morning sickness, but according to the plaintiffs, GlaxoSmithKline failed to warn their doctors about the risks.

A second lawsuit, filed in the U.S. District Court of Pennsylvania, further targets GlaxoSmithKline’s marketing practices. Court documents show that the company knew its product crosses human placental barriers during pregnancy, that they conducted studies showing pregnant women cannot safely use Zofran, that GlaxoSmithKline intentionally targeted pregnant women without providing a birth defect warning, and that they concealed important information from healthcare providers while illegally promoting Zofran to doctors.

Patients should be able to make an informed decision when given a medication. If you had been prescribed Zofran for this off-label usage, bring your case to Trantolo & Trantolo. Contact any of our Connecticut offices to speak with an attorney experienced in dangerous drug and product liability law.