Pediatric Ondansetron Dosing Guidelines
For pediatric patients, ondansetron should be dosed at 0.15 mg/kg per dose, with a maximum of 16 mg per dose, for prevention and treatment of nausea and vomiting. 1, 2
Weight-Based Dosing for Chemotherapy-Induced Nausea and Vomiting
- For chemotherapy-induced nausea and vomiting, administer 0.15 mg/kg intravenously 30 minutes before chemotherapy, with subsequent doses at 4 and 8 hours after the first dose 3, 2
- For high-emetic-risk chemotherapy, a three-drug combination of a 5-HT3 receptor antagonist (ondansetron), dexamethasone, and aprepitant is recommended for optimal antiemetic control 4
- If aprepitant cannot be used, a two-drug combination of ondansetron and dexamethasone is recommended 4
- If dexamethasone cannot be used, a combination of palonosetron and aprepitant is recommended 4
Dosing for Postoperative Nausea and Vomiting
- For prevention of postoperative nausea and vomiting, 0.05-0.1 mg/kg IV (50-100 micrograms/kg) is effective, with 0.05 mg/kg being as effective as higher doses 5
- Maximum single dose should not exceed 16 mg 3, 6
Age-Specific Considerations
- Ondansetron has been studied and used safely in children as young as 6 months of age 4, 2
- Pediatric patients have increased clearance of ondansetron compared to adults, but dosage adjustments based on age alone are not necessary 1
- For children under 4 years of age, the same weight-based dosing (0.15 mg/kg) can be used, though limited data exists for this population 7
Administration Routes and Formulations
- Ondansetron can be administered intravenously or orally 2, 7
- For oral administration, the bioavailability is approximately 59% 1
- When using oral formulations, the timing should be adjusted to account for absorption time (peak plasma concentration occurs approximately 1 hour after oral dosing) 1
Special Clinical Scenarios
- For Food Protein-Induced Enterocolitis Syndrome (FPIES), ondansetron can be administered intramuscularly at 0.15 mg/kg/dose (maximum 16 mg) for children 6 months and older experiencing moderate to severe symptoms 4
- For low-emetic-risk antineoplastic treatments, ondansetron or granisetron monotherapy is recommended 4
- For minimal-emetic-risk antineoplastic agents, routine antiemetic prophylaxis is not recommended 4
Safety Considerations
- Ondansetron is generally well tolerated in children 2
- Most common adverse events include mild to moderate headache, constipation, and diarrhea 2
- Higher loading doses (16 mg/m² with a maximum of 24 mg) have been studied and appear safe, with hypotension, fatigue, and injection site reactions being the most common adverse events 6
- Adverse events are more common in female patients and with higher cumulative doses 6
Practical Dosing Tips
- For ease of administration, doses can be rounded according to available formulations 7
- When using ondansetron for chemotherapy-induced nausea and vomiting, combining it with dexamethasone significantly improves antiemetic efficacy 4, 2
- For multi-day chemotherapy regimens, ondansetron should be continued for the duration of the emetogenic therapy 3, 2