Zofran for Children: Why Doctors Prescribe It

When Your Child Has a Stomach Flu

A girl who cared by Grandma is taking pills in bed
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If your child was recently in the ER because he was vomiting and doctors gave him a dose of Zofran, you may have noticed it seemed to help. Why, then, do doctors sometimes use Phenergan? There are a few good reasons why your child got Zofran (ondansetron) instead of Phenergan.

Zofran vs. Phenergan

For one thing, in 2006 the FDA recommended that Phenergan not be used for children under age 2.

That warning has made many doctors hesitant to use Phenergan in young children and most won't use it in children under age 2 anymore.

Even in older children, Phenergan so often causes drowsiness that many pediatricians don't like to use it. Remember that even if your child isn't vomiting, if he is too sleepy to drink when he has a stomach virus, then he will likely still become dehydrated.

Zofran has its own warning, though, at least for higher dosages that were once for nausea and vomiting associated with chemotherapy. This followed a study that found that a single 32mg dose might affect the heart's rhythm, leading to QT interval prolongation. This dose, however, is no longer available and is much higher than the 2mg to 8mg that children and teens typically get.

Zofran for Stomach Flu

But why use Zofran for the vomiting? Although Zofran is only approved for preventing nausea and vomiting for patients about to undergo chemotherapy or surgery, many medications are used off-label for other uses. And in this case, there are many research studies that show that Zofran can be helpful for treating and preventing vomiting associated with gastroenteritis or the "stomach flu."

In one study, Zofran "was effective in lowering the rates of intravenous fluid administration and hospital admission in patients with vomiting from acute gastroenteritis."

Another study showed that children with gastroenteritis, some as young as 6 months old, given Zofran were less likely to need an IV and spent less time in the ER than children who were given a placebo.

Zofran for Children

If it is so helpful in the ER at preventing and treating vomiting from gastroenteritis, how come your pediatrician hasn't always been quick to prescribe Zofran at an office visit? For one thing, there are no research studies supporting that it works in this situation. All of the studies have been done in an ER setting.

And Zofran used to be fairly expensive, with one tablet costing over $20. New generic versions of the tablets and orally disintegrating tablet form of Zofran have made it much more affordable, and if research supports it, maybe doctors will use it more for kids with the stomach flu.

Even considering the full price of Zofran, when compared to the cost of a hospital admission or even a visit to the ER, the cost of Zofran may be worth it, though. Another study did show that Zofran reduced "the need for admission in those who are treated at an initial visit to the emergency department."

Keep in mind that most of the current practice guidelines, including those from the American Academy of Pediatrics, don't recommend using medications to stop vomiting.


A randomized clinical trial comparing oral ondansetron with placebo in children with vomiting from acute gastroenteritis. Ramsook C - Ann Emerg Med - 01-APR-2002; 39(4): 397-403

Oral ondansetron useful for gastroenteritis in pediatric ER. N Engl J Med 2006;354:1698-1705.

Ondansetron Decreases Vomiting Associated With Acute Gastroenteritis: A Randomized, Controlled Trial. PEDIATRICS Vol. 109 No. 4 April 2002, pp. e62

Cheng, A. Emergency department use of oral ondansetron for acute gastroenteritis-related vomiting in infants and children. Paediatr Child Health. 2011 Mar; 16(3): 177–179.

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