Treatment for Post-Viral Cough
Start with inhaled ipratropium bromide as first-line therapy, escalate to inhaled corticosteroids if symptoms persist and affect quality of life, and reserve oral prednisone (30-40 mg daily) for severe paroxysms after excluding other causes. 1, 2
Defining Post-Viral Cough
- Post-infectious cough is diagnosed when cough persists for 3-8 weeks following an acute respiratory infection 1, 2
- If cough extends beyond 8 weeks, reclassify as chronic cough and investigate alternative diagnoses such as upper airway cough syndrome, asthma, or gastroesophageal reflux disease 1
- The diagnosis is clinical and one of exclusion, requiring assessment of multiple pathogenetic factors including postviral airway inflammation, bronchial hyperresponsiveness, mucus hypersecretion, and impaired mucociliary clearance 1
Treatment Algorithm
First-Line: Inhaled Ipratropium Bromide
Begin with inhaled ipratropium bromide, which has demonstrated efficacy in controlled trials for attenuating post-infectious cough. 1, 2
- This anticholinergic agent addresses mucus hypersecretion and airway irritation 1, 2
- A randomized controlled trial showed significant reduction in daytime cough severity (P = 0.003) after 10 days when combined with salbutamol versus placebo 3
- Ipratropium has fair-level evidence with intermediate net benefit (Grade B recommendation) 1
Second-Line: Inhaled Corticosteroids
- Add inhaled corticosteroids when cough adversely affects quality of life and persists despite ipratropium use 1, 2
- The mechanism involves suppression of airway neutrophil inflammation and bronchial hyperresponsiveness that characterizes post-viral cough 1, 2
- This carries expert opinion-level evidence with intermediate net benefit (Grade E/B recommendation) 1
Third-Line: Oral Corticosteroids for Severe Cases
For severe paroxysms, prescribe prednisone 30-40 mg daily for a short, finite period (2-3 weeks with taper) only after ruling out upper airway cough syndrome, asthma, and gastroesophageal reflux disease. 1, 2
- This approach is based on the speculation that intense airway inflammation drives persistent cough 1
- Evidence level is low with intermediate net benefit (Grade C recommendation) 1
- Reserve this for protracted, persistently troublesome cough that significantly impairs function 1
Last Resort: Central-Acting Antitussives
- Consider codeine or dextromethorphan when all other measures fail 1, 2, 4
- These opioid derivatives suppress neural cough activity centrally but carry side effects including drowsiness, nausea, constipation, and potential dependence 5, 6
- Evidence is expert opinion with intermediate net benefit (Grade E/B recommendation) 1
What NOT to Do
Antibiotics have absolutely no role in treating post-viral cough, as the cause is not bacterial infection. 1, 2, 7
- This carries expert opinion-level evidence with no net benefit (Grade I recommendation) 1
- Inappropriate antibiotic use contributes to antimicrobial resistance without improving outcomes 2, 7
Special Consideration: Pertussis
- When cough lasts ≥2 weeks with paroxysms, post-tussive vomiting, or inspiratory whooping sound, suspect Bordetella pertussis infection 1, 2
- Confirm diagnosis with nasopharyngeal culture (gold standard) 1, 2
- Macrolide antibiotics are indicated for confirmed pertussis, with patient isolation for 5 days from treatment start 2
Common Pitfalls to Avoid
- Failing to reassess at 8 weeks: Cough persisting beyond this timeframe requires reclassification as chronic cough with full evaluation for alternative diagnoses 1, 2
- Premature use of oral corticosteroids: Always exclude upper airway cough syndrome, asthma, and gastroesophageal reflux disease before prescribing systemic steroids 1, 2
- Overlooking treatment failure: Non-response should prompt immediate consideration of alternative diagnoses rather than escalating symptomatic therapy 1