What is the recommended treatment for influenza (flu) in children?

Treatment of Influenza in Children

Oral oseltamivir is the antiviral drug of choice for treating influenza in children, and should be initiated immediately in all hospitalized children with suspected influenza, children with severe or progressive illness, and children at high risk for complications—regardless of vaccination status or time since symptom onset. 1, 2

Who Should Receive Antiviral Treatment

Treatment should be offered as early as possible to the following groups:

• Any hospitalized child with clinically suspected influenza 1, 2
• Children with severe, complicated, or progressive illness attributable to influenza, regardless of duration of symptoms 1, 2
• All children at high risk for complications, including:
  • Children under 2 years of age (particularly infants under 1 year who face exceptionally high risk) 1, 2, 3
  • Children with chronic medical conditions (asthma, cardiac disease, immunocompromise, neurologic disorders) 1
  • Children within 2 weeks after influenza immunization who remain at high risk 1

Treatment may be considered for any otherwise healthy child with suspected influenza, especially if initiated within 48 hours of symptom onset, or for children whose household contacts are either younger than 6 months or have underlying medical conditions predisposing them to complications 1, 2

Recommended Medication and Dosing

Oseltamivir (oral suspension, 6 mg/mL concentration) is the preferred agent for all age groups 1, 2, 4:

Weight-Based Dosing for Children ≥12 Months:

• ≤15 kg (≤33 lb): 30 mg twice daily for 5 days 1, 2
• >15-23 kg (>33-51 lb): 45 mg twice daily for 5 days 1, 2
• >23-40 kg (>51-88 lb): 60 mg twice daily for 5 days 1, 2
• >40 kg (>88 lb): 75 mg twice daily for 5 days 1, 2

Age-Based Dosing for Infants <12 Months:

• 9-11 months: 3.5 mg/kg per dose twice daily for 5 days 2, 3
• 0-8 months (term infants): 3 mg/kg per dose twice daily for 5 days 2, 3

Preterm Infant Dosing (based on postmenstrual age):

• <38 weeks: 1.0 mg/kg per dose twice daily 2, 3
• 38-40 weeks: 1.5 mg/kg per dose twice daily 2, 3
• >40 weeks: 3.0 mg/kg per dose twice daily 2, 3

Oseltamivir can be administered with or without food, though giving with food may reduce gastrointestinal side effects 2, 3, 4

Critical Timing Considerations

Do not delay treatment while awaiting laboratory confirmation—initiate therapy immediately based on clinical suspicion, local influenza activity, and patient risk factors 1, 2, 3. The greatest clinical benefit occurs when treatment begins within 48 hours of symptom onset, reducing illness duration by approximately 36 hours (26% reduction) 2, 3. However, treatment should still be offered beyond 48 hours in hospitalized children, those with severe illness, and high-risk patients, as they continue to benefit from later initiation 1, 2.

Alternative Antiviral Agents

Inhaled zanamivir is an acceptable alternative for children ≥7 years without chronic respiratory disease, but is more difficult to administer and requires adequate inspiratory flow through the delivery device 1, 5. Zanamivir is not recommended for children with underlying airway disease due to risk of bronchospasm 1, 5.

Intravenous peramivir is approved only for acute uncomplicated influenza in non-hospitalized children ≥2 years (or ≥6 months per some formulations) who have been symptomatic ≤2 days, making it a limited option 1, 2.

Amantadine and rimantadine should not be used due to high levels of resistance among circulating influenza strains 1, 2.

Clinical Efficacy and Benefits

Timely oseltamivir treatment provides measurable benefits:

• Reduces illness duration by approximately 1.5 days when started within 36 hours of symptom onset 2, 6
• Decreases risk of otitis media by 34-44% in treated children 2, 7
• Reduces antibiotic prescriptions by approximately 10% compared to untreated children 7
• Lowers risk of complications including hospitalization and death, particularly in high-risk populations 2, 3

The drug demonstrates effectiveness against both influenza A and B, though response may be slightly less robust for influenza B 2, 7.

Safety Profile and Adverse Effects

Vomiting is the most common adverse effect, occurring in approximately 5-15% of treated children (compared to 9% with placebo), and is typically mild and transient 2, 7, 4. Diarrhea may occur in children under 1 year of age 2, 3. Despite historical concerns about neuropsychiatric adverse effects, controlled clinical trials and ongoing surveillance have failed to establish a causal link between oseltamivir and neurologic or psychiatric events 2, 4.

Antiviral Resistance Monitoring

Current surveillance data indicate that the vast majority of circulating influenza strains remain susceptible to oseltamivir, zanamivir, and peramivir, with <0.5% resistance rates for most strains 1, 3. The CDC conducts continuous monitoring of resistance patterns, and empiric treatment recommendations may be adjusted if resistant strains emerge 1.

Critical Pitfalls to Avoid

• Do not withhold treatment while awaiting laboratory confirmation in high-risk or severely ill children—clinical judgment should guide immediate treatment decisions 1, 2, 3
• Do not rely on negative rapid antigen tests to rule out influenza or make treatment decisions, as these tests have low sensitivity 2
• Do not refuse treatment beyond 48 hours in hospitalized, severely ill, or high-risk children, as they continue to benefit from later initiation 1, 2
• Ensure accurate weight-based dosing in infants and young children to avoid underdosing or overdosing 2, 3
• Do not use amantadine or rimantadine due to widespread resistance 1, 2