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Zofran and Zuplenz Side Effects

Pregnant women taking Zofran or Zuplenz to help with nausea risk being exposed to serious side effects. Studies link Zofran to an increased risk of heart defects, cleft palate and other congenital birth defects.

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Patients who are hypersensitive to selective 5-HT3 receptor antagonists have experienced hypersensitivity reactions to Zofran and Zuplenz, including anaphylaxis.

Other reported adverse effects of these drugs have manifested in the form of electrocardiographic (ECG) changes (including QT interval prolongation) and cases of Torsade de Pointes. The Zofran and Zuplenz labels also carry warnings regarding serotonin syndrome, a potential side effect of having an excess of serotonin in the body.

Pregnancy Risk and Zofran Study

Scientific studies indicate there is also a risk that Zofran may cause congenital birth defects.

In one study, 1) researchers noted there had been reports of transplacental transfer of Zofran during the first trimester of human pregnancies.

A 2012 study that examined data from the National Birth Defects Prevention Study found more than a doubling of risk of cleft palate among babies whose mothers took ondansetron during the first trimester of pregnancy. 2

A 2014 study by Danielsson et al. determined that the risks of certain heart defects in newborns whose mothers took Zofran during early pregnancy were “increased and statistically significant.” 3 Some of the most frequently encountered of these congenital malformations due to Zofran exposure were ventricular and atrial septal defects.

Common Zofran and Zuplenz Side Effects

Certain side effects are associated with Zofran and Zuplenz usage. Those most frequently encountered during clinical trials include:

  • Headache
  • Diarrhea
  • Malaise
  • Fatigue
  • Constipation
  • Dizziness
  • Hypoxia
  • Pyrexia
  • Gynecological disorders
  • Anxiety
  • Urinary retention
  • Pruritus

Rare Side Effects

Less common side effects were also reported during clinical trials Zofran and Zuplenz including:

  • Anaphylaxis
  • Bronchospasm
  • Tachycardia
  • Angina (chest pain)
  • Hypokalemia
  • Electrocardiographic alterations
  • Vascular occlusive events
  • Grand mal seizures

  1. Lyn Colvin et al, “Off-Label Use of Ondansetron in Pregnancy in Western Australia,” BioMed Research International (2013).
  2. Marlene Anderka et al., “Medications Used to Treat Nausea and Vomiting of Pregnancy and the Risk of Selected Birth Defects,” Birth Defects Research (Part A): Clinical and Molecular Teratology (2012).
  3. Bengt Danielsson et al, “Use of Ondansetron During Pregnancy and Congenital Malformations in the Infant,” Reproductive Toxicology, Vol. 50, 134–37 (2014).