What is the treatment for post infectious cough?

Treatment for Post-Infectious Cough

Start with inhaled ipratropium bromide 2-3 puffs four times daily as first-line therapy, as this has the strongest evidence for attenuating post-infectious cough in controlled trials. 1

Initial Management Approach

• Post-infectious cough is defined as cough persisting 3-8 weeks following an acute respiratory infection and is diagnosed clinically as a diagnosis of exclusion 1
• Antibiotics have no role in treatment since the cause is typically not bacterial, and repeating antibiotics after failed therapy is inappropriate 2, 1, 3
• For patients over 1 year of age, honey can be used as an adjunctive first-line symptomatic treatment 3

Stepwise Treatment Algorithm

First-Line: Inhaled Ipratropium

• Prescribe inhaled ipratropium bromide 2-3 puffs four times daily as the initial pharmacologic intervention 2, 1
• This agent has demonstrated efficacy in controlled trials with fewer systemic side effects compared to alternatives 2

Second-Line: Add Inhaled Corticosteroids (1-2 weeks if no improvement)

• Add inhaled corticosteroids (budesonide or fluticasone) when cough persists despite ipratropium and adversely affects quality of life 2, 1
• The mechanism involves suppression of airway inflammation and bronchial hyperresponsiveness that characterizes post-infectious cough 1

Alternative First-Line: Antihistamine/Decongestant Combination

• If upper airway cough syndrome is suspected (post-nasal drip symptoms), prescribe first-generation antihistamine/decongestant combination such as brompheniramine/pseudoephedrine or chlorpheniramine/phenylephrine 2
• Begin with once-daily bedtime dosing for 2-3 days, then advance to twice-daily to minimize sedation 2
• Add intranasal corticosteroid spray (fluticasone or mometasone) to decrease airway inflammation 2
• Critical caveat: Do not use nasal decongestant sprays for more than 3-5 days due to rebound congestion risk 2

Third-Line: Oral Corticosteroids for Severe Cases

• Prescribe prednisone 30-40 mg daily for 5-7 days only for severe paroxysms of cough that significantly impair quality of life 2, 1
• This should only be used after ruling out other common causes such as asthma or gastroesophageal reflux disease 2, 1

Fourth-Line: Central-Acting Antitussives

• When other measures fail, add codeine 15-30 mg or dextromethorphan 30 mg every 6 hours 2, 1
• Note that evidence for dextromethorphan efficacy in acute respiratory tract infection cough is limited 4, but it remains an option when other therapies have failed 5, 6

Systematic Evaluation if Treatment Fails After 2 Weeks

• After 2 weeks of adequate therapy without improvement, evaluate sequentially for asthma/non-asthatic eosinophilic bronchitis and gastroesophageal reflux disease 2
• If both upper airway cough syndrome and asthma treatments fail, initiate high-dose proton pump inhibitor therapy (omeprazole 40 mg twice daily) with dietary modifications 2
• GERD-related cough may require 2 weeks to several months for response, with some patients needing 8-12 weeks 2

When to Reclassify and Escalate Workup

• If cough persists beyond 8 weeks, reclassify as chronic cough and pursue further evaluation 1
• Order chest radiograph to rule out persistent pneumonia, masses, interstitial disease, or congestive heart failure in patients with chronic cough (>3 weeks duration) 2
• Consider high-resolution CT chest to evaluate for bronchiectasis, interstitial lung disease, or occult masses if all empiric therapy fails 2
• Consider bronchoscopy to evaluate for endobronchial lesions, sarcoidosis, eosinophilic bronchitis, or occult infection 2

Special Consideration: Pertussis

• When cough lasts ≥2 weeks with paroxysms, post-tussive vomiting, or inspiratory whooping sound, consider pertussis infection 1, 3
• Nasopharyngeal culture is the gold standard for diagnosis 1
• Macrolide antibiotics are indicated for confirmed pertussis, and patients should be isolated for 5 days from the start of treatment 1

Critical Pitfalls to Avoid

• Do not diagnose "unexplained cough" until completing systematic evaluation of upper airway cough syndrome, asthma, and GERD with adequate treatment trials 2
• Failing to recognize when post-infectious cough has persisted beyond 8 weeks requires reclassification as chronic cough 1
• Overlooking underlying conditions (asthma, upper airway cough syndrome, GERD) that may contribute to persistent cough 1