What is the best course of treatment for a patient with a persistent cough lasting 2 weeks, potentially with underlying conditions such as asthma or chronic obstructive pulmonary disease (COPD)?

Management of 2-Week Cough

For a patient with cough lasting 2 weeks, immediately rule out pertussis if paroxysmal coughing, post-tussive vomiting, or inspiratory whooping is present, and initiate empiric macrolide therapy while awaiting culture results; otherwise, treat as postinfectious cough with inhaled ipratropium bromide as first-line therapy. 1, 2

Immediate Diagnostic Priorities

Rule Out Pertussis First

• When cough ≥2 weeks is accompanied by paroxysmal episodes, post-tussive vomiting, or inspiratory whooping sound, diagnose pertussis unless proven otherwise. 1, 3
• Obtain nasopharyngeal aspirate or Dacron swab for culture immediately, though sensitivity is only 25-50%. 3
• Start empiric macrolide antibiotic (azithromycin or clarithromycin) without waiting for culture results if clinical presentation is consistent with pertussis, as early treatment within the first few weeks diminishes paroxysms and prevents transmission. 1, 3
• Isolate patient for 5 days after starting antibiotics to prevent spread. 1, 3

Assess for Red Flags

• Evaluate for hemoptysis, fever, night sweats, weight loss, or history of tuberculosis/cancer/AIDS—these require urgent expanded workup including chest radiography. 4
• In smokers, examine for finger clubbing with pleural effusion or lobar collapse suggesting bronchogenic carcinoma. 4

Treatment Algorithm for Postinfectious Cough (Pertussis Ruled Out)

First-Line Therapy

• Prescribe inhaled ipratropium bromide 2-3 puffs four times daily as the primary treatment, which has the strongest evidence for attenuating postinfectious cough. 1, 2, 3
• Do NOT prescribe antibiotics for postinfectious viral cough—they provide no benefit, contribute to resistance, and cause adverse effects. 1, 2, 4

Second-Line Therapy (If Cough Persists and Affects Quality of Life)

• Add first-generation antihistamine/decongestant combination (brompheniramine/pseudoephedrine or chlorpheniramine/phenylephrine) starting once-daily at bedtime for 2-3 days, then advance to twice-daily. 2
• Add intranasal corticosteroid spray (fluticasone or mometasone) to decrease airway inflammation. 2
• Consider inhaled corticosteroids when cough adversely affects quality of life and persists despite ipratropium. 1, 3

Third-Line Therapy (For Severe Paroxysms)

• Prescribe prednisone 30-40 mg daily for a short, finite period after ruling out upper airway cough syndrome, asthma, and GERD. 1, 3
• Consider central-acting antitussives (codeine or dextromethorphan) when other measures fail. 1

Evaluation for Underlying Conditions (Asthma/COPD)

If Patient Has Known Asthma or COPD

• Treat with standard antiasthmatic regimen of inhaled bronchodilators and inhaled corticosteroids if asthma is suspected as the cause. 1
• For asthmatic cough refractory to inhaled corticosteroids and bronchodilators, add leukotriene receptor antagonist before escalating to systemic corticosteroids. 1
• For severe/refractory asthmatic cough, prescribe 1-2 week course of oral corticosteroids followed by inhaled corticosteroids. 1

If Asthma Status Unknown

• Perform spirometry with bronchodilator response testing to evaluate for airflow obstruction. 4
• Normal spirometry does NOT exclude asthma or eosinophilic bronchitis. 4
• Consider methacholine challenge testing if spirometry is nondiagnostic but asthma is suspected. 1

Timeline Expectations and Follow-Up

Expected Resolution

• Postinfectious cough typically resolves spontaneously within 3-8 weeks total from symptom onset. 4
• Provide reassurance about natural history while treating symptoms. 4

When to Reassess (After 2 Weeks of Treatment)

• If no improvement after 2 weeks of adequate therapy, systematically evaluate for asthma/non-asthmatic eosinophilic bronchitis and GERD. 2
• Patients with severe cough who fit the clinical profile for GERD should receive antireflux treatment even without typical GI symptoms, as GERD can present with cough alone. 1, 2
• Initiate high-dose PPI 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, 4

When to Reclassify as Chronic Cough (>8 Weeks)

• If cough persists beyond 8 weeks total duration, reclassify as chronic cough and systematically evaluate for upper airway cough syndrome, asthma, and GERD with adequate treatment trials. 1, 3, 4
• Order chest radiograph to exclude pneumonia, malignancy, tuberculosis, bronchiectasis, and interstitial lung disease. 4

Critical Pitfalls to Avoid

• Do not use nasal decongestant sprays for more than 3-5 days due to rebound congestion risk. 2
• Do not assume GERD is ruled out simply because of prior antireflux surgery, as reflux can persist. 1, 2
• Do not abandon GERD therapy prematurely—it may require 8-12 weeks for response. 2, 4
• Do not fail to recognize the 8-week threshold where postinfectious cough becomes chronic cough requiring different evaluation. 4
• Avoid prescribing over-the-counter cough suppressants (guaifenesin, dextromethorphan) as first-line therapy—reserve for refractory cases after specific treatments fail. 5, 6