What is the recommended dose of ondansetron (Zofran) for pediatric patients?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: June 28, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the FDA Drug Label

Three double-blind, placebo-controlled trials have been performed (one US, two foreign) in 1,049 male and female patients (aged 2 to 12 years) undergoing general anesthesia with nitrous oxide The surgical procedures included tonsillectomy with or without adenoidectomy, strabismus surgery, herniorrhaphy, and orchidopexy. Patients were randomized to either single intravenous doses of ondansetron (0. 1 mg/kg for pediatric patients weighing 40 kg or less, 4 mg for pediatric patients weighing more than 40 kg) or placebo. A double-blind, multicenter, placebo-controlled trial was conducted in 670 pediatric patients aged 1 month to 24 months who were undergoing routine surgery under general anesthesia. A single 0. 1-mg/kg intravenous dose of ondansetron administered within 5 minutes following induction of anesthesia was statistically significantly more effective than placebo in preventing vomiting.

The recommended dose of ondansetron for pediatric patients is:

  • 0.1 mg/kg for patients weighing 40 kg or less
  • 4 mg for patients weighing more than 40 kg 1

From the Research

The recommended dose of ondansetron for pediatric patients is 0.15 mg/kg intravenously for preventing chemotherapy-induced nausea and vomiting, and a single oral dose based on weight for gastroenteritis-related vomiting: 2 mg for children weighing 8-15 kg, 4 mg for those 15-30 kg, and 8 mg for those over 30 kg 2.

Key Considerations

  • The dose of ondansetron may vary depending on the indication, age, and weight of the patient.
  • For post-operative nausea and vomiting, a single dose of 0.1 mg/kg up to 4 mg is commonly used 3.
  • Ondansetron works by blocking serotonin receptors in both the brain and gastrointestinal tract, which helps prevent the vomiting reflex.
  • Common side effects include headache and constipation, and the medication should be used cautiously in children with cardiac conditions or electrolyte abnormalities.

Evidence-Based Recommendations

  • A study published in 2010 found that higher doses of oral ondansetron were not superior to lower doses in reducing emesis in children with acute gastroenteritis 2.
  • Another study published in 1997 established a dose-response relationship for ondansetron in pediatric patients undergoing tonsillectomy and adenoidectomy and strabismus surgery, and found that a dose of 0.05 mg/kg was as effective as 0.1 mg/kg and 0.15 mg/kg 4.
  • A study published in 1999 compared the antiemetic efficacy of single high-dose ondansetron and multiple standard-dose ondansetron in pediatric oncology patients, and found that single high-dose ondansetron was as efficacious as the multiple standard-dose regimen 5.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.