What is the recommended management of headache in a patient with influenza B infection who is receiving antiviral therapy?

Management of Headache in Influenza B

For headache associated with influenza B, use acetaminophen or ibuprofen for symptomatic relief while treating the underlying viral infection with oseltamivir if indicated. 1

Symptomatic Management of Headache

• Acetaminophen (paracetamol) is the first-line antipyretic and analgesic for headache and fever in influenza B, with dosing appropriate for age and weight 1
• Ibuprofen or other NSAIDs are acceptable alternatives for adults and children over 6 months who can tolerate them 1
• Aspirin must be avoided in children and adolescents due to the risk of Reye's syndrome 1
• Taking antipyretics with food and maintaining adequate hydration enhances comfort and may reduce the severity of systemic symptoms including headache 1

Antiviral Therapy for the Underlying Infection

While antipyretics address the headache symptom directly, treating the influenza B infection itself with oseltamivir can shorten overall illness duration and reduce symptom severity:

• Oseltamivir 75 mg orally twice daily for 5 days is the standard adult dose for influenza B treatment 2, 3
• Pediatric weight-based dosing: ≤15 kg: 30 mg twice daily; >15–23 kg: 45 mg twice daily; >23 kg: 75 mg twice daily 2, 3
• Greatest benefit occurs when oseltamivir is started within 48 hours of symptom onset, reducing illness duration by approximately 1–1.5 days and symptom severity by up to 38% 2, 3, 4
• High-risk patients should receive oseltamivir regardless of timing, including those who are hospitalized, severely ill, immunocompromised, pregnant, under 2 years old, over 65 years old, or have chronic medical conditions 2, 3

Important Clinical Considerations

• Oseltamivir appears somewhat less effective against influenza B compared to influenza A (8.5% vs. 34% reduction in time to symptom resolution), but treatment is still recommended because even modest benefits outweigh risks in high-risk patients 5, 3
• Do not delay oseltamivir while waiting for laboratory confirmation in high-risk patients during influenza season—treat empirically based on clinical presentation 2, 5
• The most common adverse effect of oseltamivir is nausea and vomiting (occurring in 5–15% of patients), which is transient and rarely requires discontinuation; taking the medication with food reduces this risk 2, 4

When to Add Antibiotics

• Antibiotics are NOT indicated for uncomplicated influenza B with headache alone 1
• Add empiric antibiotics only if there is evidence of secondary bacterial infection: new pulmonary consolidation on imaging, purulent sputum production, clinical deterioration despite oseltamivir, or elevated inflammatory markers suggesting bacterial superinfection 1
• Common bacterial superinfections include S. pneumoniae, S. aureus, and H. influenzae, which would be covered by co-amoxiclav, cefuroxime, or a respiratory fluoroquinolone 1

Common Pitfalls to Avoid

• Do not withhold oseltamivir based solely on time since symptom onset in patients with risk factors for complications—mortality benefit persists even when treatment is initiated up to 96 hours after illness begins 2, 3
• Do not reflexively add antibiotics for viral influenza symptoms alone, as this contributes to antimicrobial resistance without clinical benefit 1
• Do not use amantadine or rimantadine for influenza B, as these older agents are only active against influenza A 1, 3