Ondansetron Dosing in Pediatric Patients
For pediatric patients with chemotherapy-induced nausea and vomiting, ondansetron should be dosed at 5 mg/m² or 0.15 mg/kg intravenously or orally, with established clinical practice supporting these weight-based or body surface area-based dosing strategies. 1
Chemotherapy-Induced Nausea and Vomiting
High and Moderate Emetogenic Risk
- Administer ondansetron at 5 mg/m² or 0.15 mg/kg as the standard pediatric dose for chemotherapy-induced nausea and vomiting 1
- Combine ondansetron with dexamethasone for optimal antiemetic control in moderate-emetic-risk chemotherapy (strong recommendation from ASCO guidelines) 1
- For high-emetic-risk chemotherapy, use a three-drug combination of ondansetron, dexamethasone, and aprepitant when possible 2
- Multiple dosing studied in trials: initial dose of 0.04 to 0.87 mg/kg (total 2.16 to 12 mg) followed by oral doses of 4 to 24 mg daily for 3 days 3
Low Emetogenic Risk
Dosing Flexibility
- Single high-dose ondansetron (0.6 mg/kg, maximum 32 mg) is as efficacious as multiple standard doses (0.15 mg/kg every 4 hours for four doses) and better facilitates administration 4
- Ondansetron 8 mg three times daily showed similar response rates in patients younger than 12 years compared to older adolescents 3
Acute Gastroenteritis
Standard Dosing
- The Infectious Diseases Society of America and American Academy of Pediatrics recommend weight-based dosing at 0.15 mg/kg (maximum 16 mg) for children >4 years with acute gastroenteritis and vomiting 5
- Ondansetron has been safely studied in children as young as 6 months of age 2
- Dose range of 0.13 to 0.26 mg/kg shows similar efficacy without increased side effects, suggesting lower doses within this range are adequate 6
Clinical Efficacy
- Single-dose ondansetron produces higher rates of vomiting cessation within 8 hours (RR 1.41) and reduces oral rehydration failure, IV hydration needs, and hospitalization rates 7
- At 24 hours, 95% of children receiving ondansetron showed improvement compared to 85% with domperidone 8
Important Caveats
- Ondansetron should not replace fluid and electrolyte therapy, which remains the mainstay of gastroenteritis treatment 5
- Use after ensuring adequate hydration or alongside rehydration efforts 5
- Exercise caution in children with heart disease due to potential QT interval prolongation 5
Postoperative Nausea and Vomiting
- Intravenous ondansetron 0.075 to 0.15 mg/kg is effective for preventing postoperative nausea and vomiting in children undergoing high-risk procedures like tonsillectomy or strabismus repair 9
- Oral ondansetron 0.1 mg/kg also demonstrates efficacy in this setting 9
- Ondansetron shows superior efficacy compared to droperidol (0.02-0.075 mg/kg) or metoclopramide (0.2-0.25 mg/kg) 9
Food Protein-Induced Enterocolitis Syndrome (FPIES)
- Administer ondansetron intramuscularly at 0.15 mg/kg/dose (maximum 16 mg) for children ≥6 months experiencing moderate to severe FPIES symptoms 2
Safety Profile
- Ondansetron is generally well tolerated in pediatric patients, rarely necessitating withdrawal 9
- Most common adverse events include mild to moderate headache, constipation, and diarrhea in chemotherapy patients 9
- Wound problems, anxiety, headache, drowsiness, and pyrexia reported most frequently post-surgery 9
- No dose-dependent increase in diarrhea episodes observed within the 0.13-0.26 mg/kg range 6