How should I manage a dry cough caused by a viral upper‑respiratory infection in an adult?

Management of Viral Dry Cough in Adults

For an adult with acute dry cough from a viral upper respiratory infection, reassurance and symptomatic treatment are appropriate—antibiotics provide no benefit and should not be prescribed. 1

Understanding the Natural Course

• Acute viral cough is self-limiting and typically lasts less than 3 weeks, with most cases resolving spontaneously without specific pharmacologic intervention. 1
• The condition is benign in the absence of significant comorbidities (such as asthma, COPD, heart disease, or immunosuppression). 1
• Post-infectious cough may persist for 3–8 weeks after the initial viral infection due to ongoing airway inflammation and bronchial hyperresponsiveness, not ongoing infection. 2

When to Investigate Further

Obtain further evaluation immediately if any of the following red flags are present:

• Hemoptysis (coughing up blood) 1
• Prominent systemic illness (high fever >4 days, severe malaise, weight loss, night sweats) 1
• Suspicion of inhaled foreign body 1
• Suspicion of lung cancer (especially in smokers >50 years) 1
• New focal chest signs on examination (crackles, diminished breath sounds, dullness to percussion) 3
• Dyspnea or tachypnea >24 breaths/min 3

Symptomatic Treatment Options

First-Line: Over-the-Counter Preparations

• Patients report subjective benefit from various over-the-counter preparations, though there is little evidence of specific pharmacological effect. 1
• Honey and lemon is a reasonable home remedy for symptomatic relief through central modulation of the cough reflex. 1, 2
• Dextromethorphan-containing preparations may be the most effective among available OTC antitussives for bothersome dry cough. 1, 3
• Guaifenesin (200–400 mg every 4 hours, up to 6 times daily) is FDA-approved to help loosen phlegm and represents a safe, nonprescription option. 2

What NOT to Prescribe

• Antibiotics are explicitly contraindicated for viral upper respiratory infection–associated cough, as they provide no clinical benefit, contribute to antimicrobial resistance, and cause adverse effects. 3, 2, 4
• Do not prescribe expectorants, mucolytics, or antihistamines for acute viral lower respiratory infections, as they are ineffective. 3
• Routine antibiotic treatment of uncomplicated acute bronchitis is not recommended regardless of cough duration. 4, 5

Management of Persistent Post-Infectious Cough (3–8 Weeks)

If dry cough persists beyond the initial viral illness but less than 8 weeks:

First-Line Pharmacologic Therapy

• Inhaled ipratropium bromide (2–3 puffs, four times daily) has the strongest evidence for attenuating post-infectious cough, with clinical improvement typically within 1–2 weeks. 2, 4

Second-Line Options

• Add an inhaled corticosteroid (fluticasone 220 mcg or budesonide 360 mcg twice daily) if cough persists despite ipratropium and markedly impairs quality of life; allow up to 8 weeks for full response. 2, 4

Third-Line for Severe Cases

• Oral prednisone (30–40 mg daily for 5–10 days) should be reserved only for severe, quality-of-life–impairing paroxysms, and only after exclusion of upper airway cough syndrome, asthma, and gastroesophageal reflux disease. 2, 4

When to Reassess and Reclassify

• If cough persists beyond 8 weeks, reclassify as chronic cough and systematically evaluate for upper airway cough syndrome, asthma, and gastroesophageal reflux disease. 2, 4
• Chest radiograph and spirometry become mandatory at the 8-week threshold to exclude structural lung disease, pneumonia, heart failure, or other pathology. 1, 4

Common Pitfalls to Avoid

• Do not prescribe antibiotics reflexively for colored sputum—green or purulent sputum does not indicate bacterial infection in viral URIs. 2
• Do not overlook medication-induced cough—review for ACE inhibitors, which cause chronic dry cough in 5–35% of patients. 4
• Do not assume all persistent cough is post-infectious—consider pertussis if cough lasts ≥2 weeks with paroxysms, post-tussive vomiting, or inspiratory whooping sound. 2
• Do not delay re-evaluation—instruct patients to return immediately if fever develops, hemoptysis occurs, or symptoms worsen. 2

Patient Education Points

• Most viral coughs resolve within 2–3 weeks, though some may persist up to 8 weeks as post-infectious cough. 2, 5
• Antibiotics will not help viral infections, even when producing colored phlegm. 1, 2
• Adequate rest, hydration, warm facial packs, steamy showers, and sleeping with the head of bed elevated provide supportive benefit. 2
• Stop smoking immediately, as tobacco exposure perpetuates cough and delays healing. 1
• Practice respiratory hygiene—use handkerchiefs, wash hands frequently, and avoid spreading infection to others. 1