Tamiflu (Oseltamivir) for Pediatric Patients
Tamiflu should be started as soon as possible (ideally within 48 hours of symptom onset) for any child hospitalized with influenza, children under 2 years old, and children with high-risk conditions or severe illness, using weight-based dosing from birth onward. 1, 2
Who Should Receive Treatment
Offer Treatment Immediately to:
- Any child hospitalized with presumed influenza 1, 2
- Children with severe, complicated, or progressive illness attributable to influenza 1, 2
- All children under 2 years of age (at increased risk of hospitalization and complications) 1, 2
- Children with high-risk medical conditions (regardless of illness duration or severity) 1, 2
Consider Treatment for:
- Any healthy child with presumed influenza when symptom reduction is desired 2
- Healthy children living with siblings <6 months old or household contacts with high-risk conditions 1, 2
Timing of Treatment
Start treatment as soon as possible after symptom onset—do not wait for laboratory confirmation. 1, 2 While optimal benefit occurs when initiated within 48 hours, treatment after 48 hours should still be considered in children with moderate-to-severe or progressive disease. 1, 2
Dosing Recommendations
Infants and Young Children:
Children ≥12 months (weight-based): 1, 3, 4
- ≤15 kg: 30 mg twice daily for 5 days
15-23 kg: 45 mg twice daily for 5 days
23-40 kg: 60 mg twice daily for 5 days
40 kg: 75 mg twice daily for 5 days
Infants 9-11 months: 3.5 mg/kg twice daily for 5 days 1, 3
Term infants 0-8 months: 3 mg/kg twice daily for 5 days 1, 3
Preterm infants (based on postmenstrual age): 1, 3
- <38 weeks: 1.0 mg/kg twice daily
- 38-40 weeks: 1.5 mg/kg twice daily
40 weeks: 3.0 mg/kg twice daily
Adolescents and Adults:
75 mg twice daily for 5 days 1, 3, 4
Formulation and Administration
Oseltamivir is available as capsules (30 mg, 45 mg, 75 mg) and oral suspension (6 mg/mL when reconstituted). 1, 3, 4 Administer with food to improve gastrointestinal tolerability. 1, 3, 4
For oral suspension dosing: 1, 3
- 30 mg = 5 mL
- 45 mg = 7.5 mL
- 60 mg = 10 mL
- 75 mg = 12.5 mL
Special Populations
Renal Impairment:
For creatinine clearance 10-30 mL/min, reduce dose to 75 mg once daily for 5 days (treatment) or 30 mg once daily for 10 days (prophylaxis). 1, 3
Premature Infants:
Use lower weight-based dosing due to immature renal function and risk of high drug concentrations. 1, 3 Dosing is based on postmenstrual age (gestational age + chronological age). 1, 3
Infants from Birth:
The FDA has approved oseltamivir for children as young as 2 weeks. 1, 4 However, the American Academy of Pediatrics supports use in both term and preterm infants from birth because benefits likely outweigh risks. 1, 2
Safety Profile
Vomiting is the most common adverse effect (15% treated vs 9% placebo in children aged 1-12 years). 1 Other gastrointestinal effects including nausea and diarrhea may occur. 3 Despite early concerns from Japan, systematic review of clinical trial data failed to establish a link between oseltamivir and neuropsychiatric events. 1
Clinical Decision-Making
Do not delay treatment while awaiting laboratory confirmation. 1, 2 Base decisions on underlying conditions, disease severity, time since symptom onset, and local influenza activity. 1, 2 Molecular assays or PCR are preferred over rapid antigen tests due to higher sensitivity, especially in hospitalized patients. 1
Important Caveats
- Standard-dose therapy is recommended—double-dose therapy showed no additional benefit in a randomized trial. 1
- Earlier treatment provides better outcomes, but some benefit exists even after 48 hours in children with moderate-to-severe disease. 1, 2
- Avoid live attenuated influenza vaccine (LAIV) within 48 hours before oseltamivir and do not use oseltamivir for 14 days after LAIV vaccination. 3