Antiviral Treatment for Influenza in Children
Oseltamivir (Tamiflu) is the antiviral drug of choice for treating influenza in children, and should be initiated immediately in all hospitalized children, those with severe illness, and all children under 2 years of age with suspected influenza—without waiting for laboratory confirmation. 1, 2
Who Should Receive Antiviral Treatment
Immediate treatment is mandatory for:
- Any hospitalized child with suspected or confirmed influenza, regardless of symptom duration 1, 2
- Any child with severe, complicated, or progressive illness attributable to influenza 1, 2
- All children under 2 years of age (exceptionally high risk for complications, hospitalization, and death) 2, 3
Treatment should be strongly considered for:
- Any otherwise healthy child with suspected influenza, especially if treatment can start within 48 hours 1, 2
- Children whose household contacts are under 6 months or have underlying medical conditions 1, 3
- Children with chronic medical conditions (asthma, diabetes, cardiac disease, immunosuppression) 1
Oseltamivir Dosing
For children ≥12 months (weight-based, twice daily for 5 days): 2, 4
- ≤15 kg: 30 mg twice daily
15-23 kg: 45 mg twice daily
23-40 kg: 60 mg twice daily
40 kg: 75 mg twice daily
For infants <12 months (age-based, twice daily for 5 days): 2, 4
- 9-11 months: 3.5 mg/kg per dose
- 0-8 months (term): 3 mg/kg per dose
- <38 weeks postmenstrual age: 1.0 mg/kg per dose
- 38-40 weeks: 1.5 mg/kg per dose
40 weeks: 3.0 mg/kg per dose
Formulation: Use oral suspension at 6 mg/mL concentration; can be given with or without food (food may reduce GI side effects). 2
Critical Timing Considerations
Do not delay treatment while awaiting laboratory confirmation—initiate immediately based on clinical suspicion and local influenza activity. 1, 2, 3 The greatest benefit occurs when treatment starts within 48 hours of symptom onset (reduces illness duration by approximately 36 hours or 26%). 1, 2 However, even beyond 48 hours, still treat high-risk children and those with severe illness, as they continue to benefit from antiviral therapy. 1, 2
When started within 12-24 hours, oseltamivir provides the most substantial benefits, including an 85% reduction in acute otitis media when initiated within 12 hours. 5
Clinical Benefits
Documented benefits of timely oseltamivir treatment include: 2, 3
- Reduces illness duration by 1.5 days (36 hours)
- Decreases risk of otitis media by 34-44%
- Reduces antibiotic prescriptions by approximately 10%
- Lowers risk of hospitalization and death in high-risk populations
Alternative Antiviral Agents
Inhaled zanamivir is an acceptable alternative for children ≥7 years without chronic respiratory disease, but is more difficult to administer. 2, 4
Intravenous peramivir is approved only for acute uncomplicated influenza in children ≥6 months who are not hospitalized and symptomatic ≤2 days. 2, 4
Amantadine and rimantadine should NOT be used due to widespread resistance. 1, 6
Safety Profile
Vomiting is the most common side effect, occurring in approximately 5-15% of children (compared to 9% with placebo), but is typically mild and transient. 2, 4 Diarrhea may occur in infants under 1 year. 2
Despite historical concerns, controlled trials and ongoing surveillance have failed to establish any link between oseltamivir and neurologic or psychiatric events. 2, 3
Critical Pitfalls to Avoid
- Never delay treatment while waiting for laboratory confirmation in high-risk or severely ill children 1, 2, 3
- Never rely on negative rapid antigen tests to rule out influenza or make treatment decisions (low sensitivity) 2, 3
- Never withhold treatment beyond 48 hours in high-risk children or those with severe illness 1, 2
- Never use amantadine or rimantadine due to widespread resistance 1, 6
Resistance Monitoring
Current surveillance shows <0.5% resistance rates to oseltamivir, zanamivir, and peramivir for most circulating influenza strains. 2, 3 The vast majority of influenza viruses remain susceptible to neuraminidase inhibitors. 3