Pediatric Dosing of Oseltamivir (Tamiflu)
The pediatric dose of oseltamivir (Tamiflu) is weight-based, with children ≥12 months receiving 30-75 mg twice daily for treatment (5 days) or once daily for prophylaxis (10 days), depending on their weight. 1
Weight-Based Dosing for Children ≥12 Months
| Body Weight | Treatment (5 days) | Prophylaxis (10 days) |
|---|---|---|
| ≤15 kg (≤33 lb) | 30 mg twice daily | 30 mg once daily |
| >15-23 kg (33-51 lb) | 45 mg twice daily | 45 mg once daily |
| >23-40 kg (51-88 lb) | 60 mg twice daily | 60 mg once daily |
| >40 kg (>88 lb) | 75 mg twice daily | 75 mg once daily |
Dosing for Infants
- Infants 9-11 months: 3.5 mg/kg twice daily for treatment; 3.5 mg/kg once daily for prophylaxis 1
- Term infants 0-8 months: 3 mg/kg twice daily for treatment; 3 mg/kg once daily for prophylaxis (for infants 3-8 months only) 1
- Infants <3 months: Prophylaxis not recommended unless situation is judged critical due to limited safety and efficacy data 1
Preterm Infant Dosing
Preterm infants require lower dosing due to immature renal function 1:
- <38 weeks postmenstrual age: 1.0 mg/kg twice daily
- 38-40 weeks postmenstrual age: 1.5 mg/kg twice daily
- >40 weeks postmenstrual age: 3.0 mg/kg twice daily
- Extremely preterm infants (<28 weeks): Consult pediatric infectious disease specialist
Administration Guidelines
- Oseltamivir is administered orally without regard to meals, though taking with food may improve gastrointestinal tolerability 1
- Available as capsules (30 mg, 45 mg, 75 mg) and oral suspension (6 mg/mL) 1
- For the 6 mg/mL suspension 1:
- 30 mg dose = 5 mL
- 45 mg dose = 7.5 mL
- 60 mg dose = 10 mL
- 75 mg dose = 12.5 mL
Special Considerations
- Treatment should be initiated within 48 hours of symptom onset for maximum effectiveness 1
- For patients with renal insufficiency (creatinine clearance 10-30 mL/min), reduce dose to 75 mg once daily for treatment or 30 mg once daily for prophylaxis 1
- FDA has approved oseltamivir for children as young as 2 weeks of age 1
- If commercial suspension is unavailable, a suspension can be compounded by retail pharmacies or capsules may be opened and mixed with sweetened liquid 1
Clinical Pearls
- Weight-based dosing is preferred over age-based dosing whenever possible 1
- The standard treatment duration is 5 days, while prophylaxis is typically 10 days after exposure 1
- Oseltamivir is effective against both influenza A and B viruses 2
- Most common side effects are gastrointestinal (nausea and vomiting), which can be minimized by taking with food 3
The most recent guidelines from the American Academy of Pediatrics (2018) provide the most up-to-date dosing recommendations, which should be followed to ensure optimal outcomes in terms of morbidity and mortality reduction 1.