How should I manage a 63-year-old woman with laboratory-confirmed influenza A who has had progressive cough and sinus pain for two weeks?

Management of Influenza A with Progressive Symptoms Beyond 2 Weeks

Start oseltamivir 75 mg orally twice daily for 5 days immediately, even though symptoms have persisted for 2 weeks, and strongly consider adding empiric antibiotics for bacterial sinusitis and possible secondary bacterial bronchitis given the progressive nature and prolonged duration of symptoms. 1, 2, 3

Immediate Antiviral Treatment

Initiate oseltamivir regardless of symptom duration because this patient has progressive disease, which mandates treatment even beyond the typical 48-hour window. 3 The Centers for Disease Control and Prevention explicitly recommends antiviral treatment for any patient with progressive influenza A, regardless of time since symptom onset. 3 Additionally, at age 63, she falls into a higher-risk category (adults ≥65 years are explicitly high-risk, and those in their 60s with any chronic conditions warrant treatment). 2, 3

• Dosing: Oseltamivir 75 mg orally twice daily for 5 days 1, 2, 3
• Expected benefit: Even in late presentation, antiviral therapy reduces secondary bacterial complications by 50%, including pneumonia and sinusitis 1
• Do not delay treatment while awaiting any additional testing or imaging 2

Empiric Antibiotic Therapy for Bacterial Coinfection

The 2-week duration with progressive symptoms strongly suggests secondary bacterial infection, particularly given the sinus pain. The British Thoracic Society guidelines specifically state that patients with worsening symptoms, recrudescent fever, or increasing breathlessness should receive antibiotics for presumed bacterial bronchitis or developing pneumonia. 4

Antibiotic Selection:

First-line choice: Co-amoxiclav 625 mg three times daily orally for 7 days 4

Alternative (if penicillin allergy): Doxycycline 200 mg loading dose, then 100 mg once daily 4

• These regimens provide coverage for Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and critically, Staphylococcus aureus, which is a major pathogen in influenza-related bacterial complications 4
• A macrolide (clarithromycin 500 mg twice daily or erythromycin 500 mg four times daily) is an alternative for those intolerant of both penicillins and tetracyclines 4

Clinical Assessment for Pneumonia

Examine specifically for:

• New or worsening dyspnea 4
• Focal chest signs on auscultation 4
• Tachypnea or increased work of breathing 4
• Oxygen saturation <95% on room air 4

If pneumonia is suspected clinically, obtain a chest radiograph and consider hospital referral based on severity. 4 The presence of bilateral chest signs or severe respiratory distress warrants urgent hospital evaluation. 4

Monitoring for Treatment Failure

Reassess within 48-72 hours for the following red flags indicating treatment failure or complications: 2, 3

• Persistent fever beyond 4-5 days without improvement 2
• Clinical deterioration after initial improvement 2, 3
• New or worsening dyspnea 4
• Development of purulent sputum 1
• Altered mental status or severe weakness 4

If no improvement after 3-5 days of combined antiviral and antibiotic therapy, this indicates possible resistant bacterial infection, inadequate antibiotic coverage, or non-infectious complications requiring further investigation. 1, 2, 3

Critical Pitfalls to Avoid

Do not withhold antiviral therapy based on the 2-week symptom duration—progressive disease is an absolute indication for treatment regardless of timing. 3 The common misconception that antivirals are only effective within 48 hours applies to uncomplicated influenza in otherwise healthy patients, not to progressive or high-risk cases. 2, 3

Do not treat with antivirals alone in this scenario. The combination of 2-week duration, progressive symptoms, and sinus pain makes bacterial superinfection highly likely, and antibiotics should be started concurrently, not as a "wait and see" approach. 4

Do not use corticosteroids as adjunctive therapy for influenza treatment unless specifically indicated for another condition (such as asthma exacerbation). 1, 3

Do not prescribe amantadine or rimantadine—resistance rates exceed 99% in circulating influenza A strains. 2, 3

Supportive Care

• Adequate hydration 2
• Acetaminophen or ibuprofen for fever and pain 2
• Isolation to prevent transmission 2
• Rest 2