What is the first line treatment for pediatric patients with influenza?

First-Line Treatment for Pediatric Influenza

Oseltamivir is the first-line antiviral treatment for pediatric patients with influenza, and should be initiated as soon as possible without waiting for laboratory confirmation, particularly in children under 2 years of age, those hospitalized, or those with severe/progressive illness. 1, 2

Who Should Receive Treatment

Offer treatment immediately to:

• All children hospitalized with suspected influenza 1, 2, 3
• Children with severe, complicated, or progressive illness attributable to influenza 1, 2, 3
• All children under 2 years of age (high-risk group for complications and hospitalization) 1, 3
• Children of any age with underlying medical conditions that predispose to complications 1, 2

Consider treatment for:

• Any otherwise healthy child with suspected influenza, especially if treatment can be initiated within 48 hours 1, 2
• Healthy children whose siblings or household contacts are younger than 6 months or have medical conditions predisposing to complications 1, 2

Medication and Dosing

Oseltamivir (oral suspension, 6 mg/mL) is the drug of choice with the following weight-based dosing for treatment (twice daily for 5 days): 2, 3, 4

Age/Weight	Dose
0-8 months	3 mg/kg per dose twice daily
9-11 months	3.5 mg/kg per dose twice daily
≥12 months, ≤15 kg	30 mg twice daily
≥12 months, >15-23 kg	45 mg twice daily
≥12 months, >23-40 kg	60 mg twice daily
≥12 months, >40 kg	75 mg twice daily

Alternative agents (less preferred):

• Inhaled zanamivir: acceptable for children >7 years without chronic respiratory disease, but more difficult to administer 2, 5
• IV peramivir: approved only for children ≥2 years with acute uncomplicated influenza 2, 3

Timing of Treatment

Initiate treatment immediately upon clinical suspicion—do not delay while awaiting confirmatory testing. 1, 2, 3

• Greatest benefit occurs when started within 48 hours of symptom onset 1, 2, 6
• Treatment started within 12 hours can reduce acute otitis media incidence by 85% 6
• However, treatment beyond 48 hours is still recommended for high-risk children (especially infants and those hospitalized) as they continue to benefit from later initiation 1, 2, 3

Clinical Efficacy

In children with laboratory-confirmed influenza, oseltamivir:

• Reduces median duration of illness by 36 hours (26% reduction) 1, 2
• Decreases risk of otitis media by 34% 1, 2
• Reduces risk of hospitalization and death 2, 3
• When started within 24 hours in children 1-3 years with influenza A, shortens illness by 3.5 days and reduces parental work absenteeism by 3 days 6

Common Adverse Effects and Safety

Vomiting is the most common side effect:

• Occurs in approximately 5-15% of treated children (compared to 9% with placebo) 1, 2
• Diarrhea may occur in infants under 1 year 2, 3
• Administering with food may improve gastrointestinal tolerability 3

Neuropsychiatric concerns:

• Despite historical reports from Japan, controlled clinical trials and ongoing surveillance have failed to establish a link between oseltamivir and neurologic or psychiatric events 1, 2

Diagnostic Testing Considerations

Do not delay treatment while awaiting test results—clinical judgment based on symptoms and local influenza activity should guide immediate treatment decisions. 1, 2, 3

• Rapid antigen tests have low sensitivity (10-70%); negative results should not be used to rule out influenza or withhold treatment 1
• Rapid molecular assays (sensitivity 86-100%) and PCR are preferred for hospitalized patients but should not delay treatment initiation 1
• Positive rapid tests are helpful for reducing unnecessary additional testing and promoting antimicrobial stewardship 1

Antiviral Resistance

Current influenza strains show minimal resistance to oseltamivir (<0.5% of circulating strains). 2, 3

• Amantadine and rimantadine should NOT be used due to high resistance levels 1, 2, 3
• The CDC continuously monitors resistance patterns 2

Critical Clinical Pitfalls to Avoid

• Do not withhold treatment beyond 48 hours in high-risk children (infants, hospitalized, or those with underlying conditions)—they still benefit from later initiation 1, 2, 3
• Do not delay treatment while awaiting laboratory confirmation when influenza is circulating in the community 1, 2
• Ensure accurate weight-based dosing, particularly in infants where underdosing may reduce efficacy 2, 3
• Do not rely on negative rapid antigen tests to exclude influenza or make treatment decisions due to poor sensitivity 1

Special Considerations for Infants

The AAP supports oseltamivir use in both term and preterm infants from birth, despite FDA approval starting at 2 weeks of age, because benefits outweigh risks in this high-risk population. 1, 3, 4

• Preterm infants require adjusted dosing based on postmenstrual age 3
• Infants under 1 year are at particularly high risk for complications and should always receive treatment 1, 3