For more information or confidential assistance
se habla español

Zofran and Morning Sickness

pregnant woman wearing white in profileAs many pregnant women will attest, the term “morning sickness” is a misnomer, considering nausea and vomiting can occur at all hours of the day and evening. An estimated 60 to 80 percent of all women experience some form of morning sickness during their pregnancy, which can manifest as extreme nausea, queasiness and vomiting. Thought to be triggered by hormonal fluctuations, this condition is most prevalent during the first trimester of pregnancy, and usually begins around the sixth week of gestation, though some women may experience symptoms as early as two weeks after conception.

Morning sickness risk factors and symptoms

Morning sickness commonly affects women of all ages and ethnicities, though certain risk factors include:

  • A family history of hyperemesis gravidarum (an extreme type of morning sickness that warrants medical intervention)
  • Pregnancy with twins or multiples
  • Previous history of morning sickness
  • Inclination toward nausea associated with smells, motion sickness or estrogen exposure from birth control pills

Hyperemesis gravidarum differs from regular morning sickness in the following ways:

  • Severe nausea accompanied by persistent/uncontrolled vomiting
  • Unrelenting nausea throughout the day
  • Vomiting that results in dehydration and/or malnutrition
  • Decrease in urination
  • Extreme fatigue
  • Low blood pressure
  • Electrolyte imbalance
  • Confusion and fainting
  • Weight loss of at least 5 percent of pre-pregnancy weight

Treatments for severe hyperemesis gravidarum

In milder cases of hyperemesis gravidarum, expectant women may find relief from bed rest, dietary changes and over-the-counter antacids. However, those who suffer from severe morning sickness, resulting in dehydration and weight loss, may be admitted to the hospital for IV fluids to help restore vitamins, nutrients and electrolytes. In addition, doctors may prescribe anti-nausea meds, including Diclegis, metoclopramide or ondansetron (Zofran), which blocks serotonin and is prescribed as an “off-label” treatment for morning sickness.

In the majority of pregnancies, mild cases of morning sickness pose little threat to mother and baby, but frequent vomiting and total food aversion can lead to more serious complications, if not addressed promptly.

Homeopathic and alternative treatments for persistent morning sickness have come to include:

  • Herbal remedies including peppermint and ginger
  • Hypnosis
  • Aromatherapy combined with reflexology
  • Therapeutic doses of Vitamin B6
  • Acupuncture
  • Acupressure

Zofran and morning sickness

Since morning sickness is a natural and expected component of most pregnancies, mitigating its unpleasant side effects often requires a multi-pronged approach. The only drug approved by the FDA for this very condition is Diclegis – a combination of doxylamine and pyridoxine. And while Zofran has frequently been prescribed to pregnant women for morning sickness, the medication was never approved by the FDA for this particular purpose, as risk of fetal injury has yet to be determined.

Manufactured by GlaxoSmithKline (GSK), Zofran is a 5-HT3 receptor antagonist that is approved for the prevention of vomiting and nausea in patients undergoing chemo or radiation therapy, as well as individuals waking from general anesthesia.

It remains unclear how ondansetron can affect the fetus in utero, but a recent study indicates that the drug is characterized by “rapid transplacental transfer and longer elimination half-life in neonates compared to their mother.” The findings were published in the medical journal Clinical Pharmacology & Therapeutic and underscore the importance of further investigation into Zofran pregnancy risks since the drug can cross the placental barrier.

Prior studies on Zofran use by expecting women and the risk for birth defects have yielded conflicting results. For instance, research published in the February 28, 2013 edition of the New England Journal of Medicine states that “ondansetron taken during pregnancy was not associated with a significantly increased risk of adverse fetal outcomes.”

In August of 2013, a different group of researchers analyzed data from the same national registries as the NEJM study and found a two-fold increase in incidence of heart defects in babies who were exposed to Zofran during the first trimester. Their results were presented at the International Society of Pharmacoepidemiology conference in Montreal.

Possible Zofran risks to mother and child

According to Health Canada, two Canadian patients reported suffering serotonin syndrome – a potentially life-threatening condition — after taking drugs like Zofran, dolasetron (Anzemet), and granisetron (Kytril and generics) for approved uses. Both patients recovered fully, but the agency issued health alerts warning about risk of irregular heartbeats and serotonin syndrome with the medications.

The FDA classifies Zofran as a category B pregnancy drug, meaning that clinical trials in animals failed to reveal evidence of fetal harm. Beyond warning about the potential for heart arrhythmias and potentially fatal cardiac risks to adult patients, the FDA has yet to publish a warning cautioning against Zofran use during pregnancy.

Since prescribing medication for off-label uses is not illegal in the United States, and the long-term implications of Zofran for morning sickness treatment are still uncertain, it remains to be seen if GSK will be held liable in emerging product liability lawsuits alleging Zofran-related birth defects. Zofran litigation is only just unfolding against the health care giant, with a handful of claims filed in the United States.

  1., Hyperemesis Gravidarum
  2. Mayo Clinic, Morning Sickness
  3., Morning Sickness
  4., Ondansetron: New and troubling data
  5. New England Journal of Medicine, Ondansetron in Pregnancy and Risk of Adverse Fetal Outcomes
  6. National Institutes of Health, Placental transfer of ondansetron during early human pregnancy