What is the first line of treatment for post-viral cough?

First-Line Treatment for Post-Viral Cough

Inhaled ipratropium bromide should be tried as the first-line treatment for post-viral cough as it has demonstrated efficacy in attenuating symptoms in controlled trials. 1, 2

Understanding Post-Viral Cough

• Post-viral cough (or post-infectious cough) is defined as a cough persisting for 3-8 weeks following symptoms of an acute respiratory infection 1
• The pathogenesis is thought to be due to extensive inflammation and disruption of upper and/or lower airway epithelial integrity, often associated with excessive mucus hypersecretion and/or transient airway and cough receptor hyperresponsiveness 3
• If cough persists beyond 8 weeks, it should be reclassified as chronic cough and evaluated for other causes 1, 3

Treatment Algorithm

First-Line Therapy

• Inhaled ipratropium bromide is the recommended first-line treatment as it has shown effectiveness in controlled trials for attenuating post-infectious cough 1, 2
• In a randomized, double-blind, placebo-controlled trial, ipratropium bromide significantly reduced day and night cough severity compared to placebo 4
• The mechanism is thought to be through anticholinergic effects that reduce airway secretions and bronchial hyperresponsiveness 1

Second-Line Therapy

• Inhaled corticosteroids should be considered when:
  • Cough adversely affects quality of life 1
  • Cough persists despite use of inhaled ipratropium 1
  • The mechanism is thought to be suppression of airway inflammation and bronchial hyperresponsiveness 1, 5

For Severe Cases

• For severe paroxysms of post-infectious cough, a short course of oral prednisone (30-40 mg daily) tapering over 2-3 weeks may be considered 3
• This should only be used after ruling out other common causes of persistent cough such as upper airway cough syndrome, asthma, or gastroesophageal reflux disease 1

When Other Measures Fail

• Dextromethorphan can be considered for patients with a dry and bothersome cough, particularly when it disrupts sleep 6
• Codeine may be considered for short-term symptomatic relief, though evidence for its efficacy in post-viral cough is limited 6

Medications to Avoid

• Antibiotics have no role in treating post-infectious cough unless there is confirmed bacterial infection, as the cause is typically not bacterial 1, 3, 6
• The exception is confirmed pertussis infection (whooping cough), which requires macrolide antibiotics 1
• Expectorants and mucolytics lack consistent evidence for beneficial effects in post-infectious cough 6
• Guaifenesin is only indicated to help loosen phlegm and thin bronchial secretions to make coughs more productive, but has limited evidence for post-viral cough specifically 7

Special Considerations

• When cough lasts ≥2 weeks with paroxysms, post-tussive vomiting, or inspiratory whooping sound, consider pertussis infection which requires specific diagnosis and treatment with macrolide antibiotics 1
• In children, post-viral cough may be particularly common and can affect school attendance and daily activities 8
• Recent research suggests that post-COVID-19 cough may have similar mechanisms to other post-viral coughs and may respond to similar treatments 5

Common Pitfalls to Avoid

• Failing to recognize when post-infectious cough has persisted beyond 8 weeks, which requires reclassification as chronic cough 1
• Inappropriate use of antibiotics for non-bacterial causes of post-infectious cough 1, 6
• Overlooking underlying conditions that may contribute to persistent cough (asthma, upper airway cough syndrome, gastroesophageal reflux disease) 1
• Using cough suppressants when the cough is productive and helping to clear mucus 6