What is the treatment for post infectious cough?

Treatment for Post-Infectious Cough

For adult patients with post-infectious cough, a stepwise approach starting with inhaled ipratropium bromide is recommended as first-line therapy, followed by inhaled corticosteroids if needed, with central-acting antitussives reserved for refractory cases. 1

Definition and Diagnosis

• Post-infectious cough is defined as cough persisting for 3-8 weeks following symptoms of an acute respiratory infection 2
• If cough persists beyond 8 weeks, it should be reclassified as chronic cough and evaluated for other causes 1, 2
• Diagnosis is clinical and one of exclusion, requiring careful assessment of potential underlying pathogenetic factors 1

Treatment Algorithm

First-Line Therapy

• Inhaled ipratropium bromide should be tried first as it has demonstrated efficacy in attenuating post-infectious cough in controlled trials 1
• Antibiotics have no role in treatment unless there is confirmed bacterial infection (such as pertussis) as the cause is typically not bacterial 1

Second-Line Therapy

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

For Severe Cases

• Oral prednisone (30-40 mg daily) for a short, finite period may be prescribed for severe paroxysms of post-infectious cough 1
• This should only be considered after ruling out other common causes of cough such as upper airway cough syndrome, asthma, or gastroesophageal reflux disease 1

When Other Measures Fail

• Central-acting antitussive agents such as codeine and dextromethorphan should be considered when other treatments fail 1
• These medications can provide symptomatic relief by suppressing the cough reflex centrally 3, 4
• Guaifenesin may help loosen phlegm and thin bronchial secretions to make coughs more productive 5

Special Considerations

Pertussis (Whooping Cough)

• When cough lasts ≥2 weeks with paroxysms, post-tussive vomiting, or inspiratory whooping sound, consider pertussis infection 1, 2
• Pertussis requires specific diagnosis (nasopharyngeal culture is the gold standard) 1
• Macrolide antibiotics are indicated for confirmed pertussis, and patients should be isolated for 5 days from the start of treatment 1

Common Pitfalls to Avoid

• Failing to recognize when post-infectious cough has persisted beyond 8 weeks, which requires reclassification as chronic cough 1, 2
• Inappropriate use of antibiotics for non-bacterial causes of post-infectious cough 1, 2
• Overlooking underlying conditions that may contribute to persistent cough (asthma, UACS, GERD) 1, 2
• Underestimating the limited efficacy of dextromethorphan in cough associated with acute upper respiratory tract infection 6

Monitoring and Follow-up

• Patients should be followed up within 4-6 weeks after initial evaluation 2
• If cough persists beyond 8 weeks, further evaluation for chronic cough causes is warranted 1, 2
• Treatment response should be assessed using validated cough severity tools 2, 7