What are the treatment options for incessant coughing?

Treatment of Incessant Coughing

For incessant coughing, treatment must follow a systematic algorithmic approach targeting the most common causes sequentially: upper airway cough syndrome (UACS) first, then asthma, followed by non-asthmatic eosinophilic bronchitis (NAEB), and finally gastroesophageal reflux disease (GERD), with each trial lasting 1-4 weeks before moving to the next step. 1

Initial Assessment and Red Flags

Before initiating empiric therapy, determine if the patient is:

• Taking an ACE inhibitor (discontinue and wait 1-4 weeks for resolution, though some patients may take up to 3 months) 1
• A current smoker (smoking cessation is mandatory) 1
• Presenting with red flags: hemoptysis, breathlessness, prolonged fever, weight loss, or symptoms persisting beyond 3 weeks (requires immediate diagnostic workup including chest radiograph and spirometry) 1

Algorithmic Treatment Approach

Step 1: Upper Airway Cough Syndrome (UACS) - First-Line Treatment

Treat empirically for postnasal drip/rhinosinusitis:

• First-generation antihistamines with decongestants are the initial therapy 1
• Response typically occurs within 1-2 weeks 1
• If baseline spirometry is normal, proceed to Step 2 if no improvement 1

Step 2: Asthma - Second-Line Treatment

Even with normal spirometry, asthma can cause chronic cough:

• Start with inhaled beta-agonists and inhaled corticosteroids 1
• If ineffective, add oral leukotriene inhibitors before escalating to oral corticosteroids 1
• Oral corticosteroids (prednisolone) should be considered for diagnostic/therapeutic trial when inhaled therapy fails 1
• The vast majority of asthmatic cough responds to treatment within 1-2 weeks 1

Step 3: Non-Asthmatic Eosinophilic Bronchitis (NAEB)

If UACS and asthma treatments fail:

• Perform induced sputum analysis to detect eosinophils 1
• NAEB responds predictably to corticosteroid therapy 1
• This diagnosis should be considered before GERD due to straightforward diagnosis and predictable response 1

Step 4: Gastroesophageal Reflux Disease (GERD)

Empiric GERD therapy is recommended for patients with: chronic cough >2 months, normal chest radiograph, nonsmoker, not on ACE inhibitors, and failed treatment for UACS/asthma/NAEB (this profile has 92% likelihood of GERD-induced cough) 1

GERD Treatment Protocol:

• Dietary modifications: No more than 45g fat per 24 hours, eliminate coffee, tea, soda, chocolate, mints, citrus products (including tomatoes), and alcohol 1
• Proton pump inhibitor (PPI) at high doses 1
• Add prokinetic therapy (metoclopramide) if no response to PPI alone 1
• Critical timing: Response may take 2 weeks to several months—this is more variable than UACS, asthma, or NAEB 1
• If no improvement after 3 months of intensive medical therapy, consider 24-hour esophageal pH monitoring or antireflux surgery 1

Symptomatic Cough Suppression

While treating underlying causes, symptomatic relief can be provided:

Preferred Antitussive Options:

• Dextromethorphan 60mg provides maximum cough reflex suppression (standard OTC doses of 15-30mg are subtherapeutic) 2
• Honey and lemon mixtures are effective for benign viral cough and should be tried first 1, 2
• Menthol inhalation provides acute but short-lived relief 2

Medications to Avoid:

• Codeine and pholcodine have no greater efficacy than dextromethorphan but significantly worse side effect profiles (drowsiness, nausea, constipation, physical dependence) 2
• Combination products should be avoided 3

Refractory or Unexplained Chronic Cough

If cough persists after systematic treatment of all common causes:

• Perform chest CT scan and consider bronchoscopy 1
• Rule out uncommon causes including foreign body, drug-induced cough, bronchiectasis, or malignancy 1
• Consider cough hypersensitivity syndrome and trial of gabapentin or pregabalin 4, 5
• Speech therapy may provide benefit for refractory cases 4, 5

Common Pitfalls to Avoid

• Do not diagnose idiopathic cough until thorough evaluation of all common causes with appropriate treatment trials has been completed 1
• Do not use subtherapeutic doses of antitussives—standard OTC dextromethorphan doses are ineffective 2
• Do not give up on GERD too early—response can take up to 3 months, unlike other causes 1
• Do not continue empiric therapy beyond 3 weeks without reassessment if no improvement is seen 1
• Approximately 90% of chronic cough has common nonmalignant etiologies that respond to this systematic approach 4