Treatment of Cough and Sore Throat in a Healthy 18-Year-Old After Four Days of Influenza-Like Illness
For this healthy 18-year-old presenting after four days of influenza-like illness, prescribe oseltamivir 75 mg orally twice daily for 5 days along with symptomatic treatment using ibuprofen or naproxen for pain and fever relief. 1, 2, 3
Antiviral Therapy
Oseltamivir remains indicated even at day four of symptoms in this patient, as the American Academy of Pediatrics and British Infection Society guidelines support antiviral use within 6 days of symptom onset, particularly in patients with ongoing symptoms. 1, 2
The standard adult dose is oseltamivir 75 mg orally twice daily for 5 days. 1, 4
While maximum benefit occurs when started within 48 hours, treatment initiated at day four can still reduce illness duration and prevent complications, especially if symptoms are progressive or severe. 1, 2
Symptomatic Management
Prescribe ibuprofen (400-600 mg every 6-8 hours as needed) or naproxen for throat pain, headache, and fever control, as these NSAIDs are specifically recommended by German clinical practice guidelines for sore throat symptom relief. 3, 5
Acetaminophen (650 mg every 4-6 hours as needed) is an alternative if NSAIDs are contraindicated. 6
Encourage adequate oral fluid intake to maintain hydration. 2
Antibiotic Decision-Making
Do not prescribe antibiotics at this time unless specific features of bacterial superinfection develop. 7, 3
When to Consider Antibiotics
Antibiotics should only be added if the patient develops:
Worsening symptoms after initial improvement (recrudescent fever or increasing dyspnea), suggesting bacterial superinfection. 7
Signs of bacterial pharyngitis with a clinical score ≥3 points using Centor/McIsaac/FeverPAIN criteria (tonsillar exudates, tender anterior cervical lymphadenopathy, fever >38°C, absence of cough). 3, 5
Evidence of suppurative complications such as acute otitis media, sinusitis, or peritonsillar abscess. 7, 8
If Antibiotics Become Necessary
First-line choice: Co-amoxiclav (amoxicillin-clavulanate) 625 mg orally three times daily for 5-7 days to cover S. pneumoniae, S. aureus, and H. influenzae—the most common bacterial pathogens complicating influenza. 7, 4
Alternative for penicillin allergy: Clarithromycin 500 mg orally twice daily for 5-7 days or doxycycline 100 mg twice daily on day 1, then 100 mg daily. 7
Important Clinical Context
Why Antibiotics Are Not Routinely Indicated
Multiple high-quality trials demonstrate that antibiotics do not benefit previously healthy adults with acute bronchitis complicating influenza in the absence of pneumonia. 7
Even when antibiotics reduce sore throat symptoms, the absolute benefit is modest—reducing symptoms by approximately half a day at day three, with 82% of untreated patients symptom-free by one week. 9, 8
The number needed to treat to prevent one case of sore throat at day three is 6, but increases to 18 by one week as most cases resolve spontaneously. 8
Red Flags Requiring Urgent Evaluation
Advise the patient to seek immediate medical attention if they develop:
Respiratory distress (increased respiratory rate, chest retractions, breathlessness with chest signs). 7, 2
Signs of sepsis (extreme pallor, hypotension, persistent high fever despite antipyretics). 7
Common Pitfalls to Avoid
Do not withhold oseltamivir simply because 48 hours have passed—guidelines support treatment up to 6 days from symptom onset, particularly in patients with ongoing or progressive illness. 1, 2
Do not prescribe antibiotics "just in case" for uncomplicated influenza-like illness, as this contributes to antimicrobial resistance without meaningful clinical benefit in previously healthy adults. 7, 3
Do not rely on the color of nasal discharge alone to diagnose bacterial infection—purulent discharge is common in viral infections and does not mandate antibiotic therapy without other supporting features. 4
Avoid aspirin in patients under 18 years due to Reye's syndrome risk, though this patient at 18 years can safely use NSAIDs. 7