Treatment Options for Persistent Cough
The most effective approach to managing persistent cough requires systematic investigation of underlying causes followed by targeted treatment based on the specific etiology.
Initial Assessment and Classification
- Determine if the cough is acute (<3 weeks), subacute (3-8 weeks), or chronic (>8 weeks) to guide treatment approach 1
- Perform chest radiograph and spirometry as mandatory initial tests 2
- Rule out serious conditions requiring specific treatment such as pneumonia, pulmonary embolism, or malignancy 1
- Consider if the patient is taking ACE inhibitors, as these are a common cause of persistent cough 2
Common Causes and Targeted Treatments
Upper Airway Cough Syndrome (UACS)
- Most common cause of persistent cough (up to 56% of cases) 3
- For prominent upper airway symptoms, prescribe a trial of topical corticosteroids 2
- Consider antihistamines, though efficacy reports vary 2
Asthma and Cough Variant Asthma
- Present in 14-25% of persistent cough cases 4, 3
- Perform bronchial provocation testing in patients with normal spirometry 2
- Trial of inhaled corticosteroids and bronchodilators is recommended 2
- Consider oral leukotriene inhibitors before oral corticosteroids 2
Gastroesophageal Reflux Disease (GERD)
- Accounts for 5-10% of persistent cough cases 4, 3
- May occur without typical gastrointestinal symptoms 2
- Intensive acid suppression with proton pump inhibitors and alginates should be undertaken for a minimum of 3 months 2
- Note: In patients with unexplained chronic cough and negative workup for acid GERD, proton pump inhibitors are not recommended 2
Non-Asthmatic Eosinophilic Bronchitis (NAEB)
- Consider after ruling out UACS and asthma 2
- Diagnosis made through induced sputum testing for eosinophils 2
- Responsive to corticosteroid therapy 2
Postinfectious Cough
- Consider when cough has been present for 3-8 weeks following respiratory infection 2
- Antibiotics have no role unless bacterial infection is confirmed 2, 1
- Consider trial of inhaled ipratropium bromide 2, 1
- For severe paroxysms, consider short course of prednisone (30-40 mg daily) 2
Symptomatic Treatment Options
For Acute or Subacute Cough
- Dextromethorphan is recommended for dry, bothersome cough, particularly when it disrupts sleep 1, 5
- Use with caution in patients taking MAOIs or with chronic productive cough 5
- Codeine may be considered for short-term relief but has limited efficacy 1
- Inhaled ipratropium bromide is recommended for cough suppression 1
For Chronic Unexplained Cough
- Consider multimodality speech pathology therapy 2
- Gabapentin may be tried with careful discussion of side effects and risk-benefit profile 2
- Start at 300 mg once daily and titrate up to maximum tolerable dose of 1,800 mg daily in divided doses 2
- Avoid inhaled corticosteroids if tests for bronchial hyperresponsiveness and eosinophilia are negative 2
Special Considerations
Smoking-Related Cough
- One of the most common causes of persistent cough 2
- Smoking cessation should be encouraged as it leads to significant symptom improvement 2
Medications to Avoid
- Expectorants, mucolytics, and antihistamines lack consistent evidence for beneficial effects in acute lower respiratory tract infections 1
- Antibiotics should not be used for viral infections or postinfectious cough 2, 1
- Combination cough preparations should not be prescribed 6
When to Refer to Specialist Care
- When cough persists despite systematic evaluation and treatment trials 2
- Consider referral to a specialist cough clinic 2
- High-resolution CT scan and bronchoscopy may be needed for unexplained cases 2
Common Pitfalls to Avoid
- Failing to consider GERD as a cause for cough 2
- Using cough suppressants when cough is productive and helping clear mucus 1
- Not recognizing when cough persists beyond expected timeframes, which may indicate a serious condition 1
- Making a diagnosis of unexplained cough before ruling out uncommon causes 2