Ondansetron Dosing Recommendations for Pediatric Patients

Oral Weight‑Based Dosing

• For children weighing ≤ 15 kg, give 2 mg per oral dose; for those > 15 kg to ≤ 23 kg, give 4 mg per oral dose (maximum single dose 16 mg) 1

Intravenous/Intramuscular Dosing

• The standard IV or IM dose is 0.15 mg/kg (maximum 16 mg per dose) and may be repeated every 8 hours as needed 1

Gastroenteritis‑Associated Vomiting

• Single IM dose of 0.15 mg/kg (maximum 16 mg) is recommended for children ≥ 6 months 1
• For mild symptoms (1–2 vomiting episodes), start with oral rehydration; give ondansetron if the child is ≥ 6 months 1
• For moderate symptoms (≥ 3 episodes with lethargy), administer 0.15 mg/kg IM 1
• For severe symptoms, give 0.15 mg/kg IV (maximum 16 mg) 1

Age‑Specific Considerations

• Infants 6 months to <12 months: dose 0.15 mg/kg per administration 1
• Infants <6 months: limited safety data; use ondansetron only when the clinical situation is judged critical 1