Intravenous Ondansetron Dosing Guidelines for Pediatric Patients

Chemotherapy‑Induced Nausea and Vomiting

For children receiving chemotherapy, administer ondansetron 0.15 mg/kg intravenously per dose (up to a maximum of 16 mg per dose) for three doses; a 16 kg child would receive 2.4 mg per dose. 1

In the peri‑operative setting for children ≤40 kg, give a single intravenous dose of ondansetron 0.1 mg/kg (maximum 16 mg); a 16 kg child would receive 1.6 mg. 1

Dose & Age: Ondansetron 0.15 mg/kg IV (maximum 16 mg per dose) is recommended for children ≥6 months of age; a 16 kg child receives 2.4 mg IV. [2][3]1
Severity‑Based Administration:
- Severe presentation (≥3 vomiting episodes with marked lethargy, hypotonia, or cyanotic appearance): give IV ondansetron 0.15 mg/kg after IV access. [2][3]1
- Moderate presentation (≥3 vomiting episodes with mild lethargy): give IM ondansetron 0.15 mg/kg if age >6 months. [2][3]
- Mild presentation (1–2 vomiting episodes, no lethargy): consider IM ondansetron 0.15 mg/kg if age ≥6 months. [2][3]

Monitor for QT‑interval prolongation in children with congenital heart disease, electrolyte disturbances, or concomitant QT‑prolonging drugs. 2
Ondansetron is not recommended for postoperative use in infants <1 month old and is contraindicated for FPIES in children <6 months old. 2