What is effective cough therapy?

Effective Cough Therapy

The most effective cough therapy is identifying and treating the specific underlying cause—when the etiology is established, targeted therapy is highly successful, whereas currently available nonspecific cough suppressants are severely limited by lack of efficacy and unacceptable side effects. 1, 2

Treatment Strategy Based on Cough Type

For Chronic Cough (>8 weeks)

Systematically evaluate and treat the three most common causes sequentially: upper airway cough syndrome (UACS), asthma, and gastroesophageal reflux disease (GERD). 3, 2

Step 1: Upper Airway Cough Syndrome (UACS)

• Initiate first-generation antihistamine/decongestant combination as first-line therapy 3, 2
• First-generation sedating antihistamines (like chlorpheniramine) are particularly effective for nocturnal cough due to their sedative properties 3, 4

Step 2: Asthma/Nonasthmatic Eosinophilic Bronchitis

• For suspected asthma: inhaled corticosteroids combined with long-acting β-agonists 2
• For nonasthmatic eosinophilic bronchitis: inhaled corticosteroids alone 2

Step 3: Gastroesophageal Reflux Disease

• High-dose proton pump inhibitor (PPI) therapy with dietary modifications and lifestyle changes 3, 2
• Add prokinetic therapy if minimal response to PPI 2

Critical caveat: Multiple simultaneous causes are present in 59% of chronic cough cases—sequential and additive therapy is often necessary rather than stopping after finding one cause. 3

For Symptomatic Relief of Nonproductive Dry Cough

Dextromethorphan is the first-line antitussive for symptomatic relief due to substantial benefit and favorable safety profile compared to other agents. 5, 6

Dextromethorphan Dosing

• Maximum cough reflex suppression occurs at 60 mg with prolonged effect 3, 5
• FDA-approved for temporary relief of cough due to minor throat and bronchial irritation 6
• More effective than codeine with fewer side effects 5

Alternative Symptomatic Options

• Menthol lozenges or inhalation: provides acute but short-lived suppression 3, 5
• Honey and lemon mixtures: effective home remedy for symptomatic relief 1, 5
• Codeine: may be used for short-term relief but has limited efficacy for upper respiratory infections and carries risks of respiratory depression, drowsiness, constipation, and physical dependence 5, 7
• Benzonatate: consider only for opioid-resistant cough when other options fail 5

Initial Assessment Requirements

Before initiating therapy, complete these essential steps:

• Obtain chest radiograph to rule out pneumonia, structural abnormalities, masses, interstitial disease, or heart failure 3, 2
• Review medication list and discontinue ACE inhibitors if present—they commonly cause persistent dry cough 3, 2
• Determine cough duration: acute (<3 weeks), subacute (3-8 weeks), or chronic (>8 weeks) 3, 2
• Advise smoking cessation for smokers—can resolve cough within 4 weeks 2

What Does NOT Work

Avoid these ineffective interventions:

• Antibiotics for nonproductive cough due to viral infections, even when phlegm is present 5
• Expectorants, mucolytics, and bronchodilators (like albuterol) for acute nonproductive cough 5
• Zinc preparations for acute cough due to common cold 5

Common Pitfalls to Avoid

• Do not rely solely on cough characteristics (timing, quality, productivity) for diagnosis—they have limited diagnostic value and nocturnal cough does not predict etiology 3, 2
• Do not assume nocturnal cough indicates psychogenic or habit cough—this is diagnostically unreliable 3
• Do not treat only one potential cause and stop—multiple factors often contribute simultaneously 2
• Do not use higher doses of dextromethorphan without checking other ingredients—some preparations contain paracetamol which can cause toxicity 5

When to Seek Specialist Referral

Consider referral to a cough specialist if cough persists despite sequential trials of therapy for all three common causes (UACS, asthma, GERD) 2. For refractory chronic cough with uncertain etiology and negative evaluation for life-threatening causes, consider cough hypersensitivity syndrome managed with gabapentin or pregabalin and speech therapy 8.

Red Flags Requiring Urgent Evaluation

Patients should seek immediate medical attention for: hemoptysis, breathlessness, prolonged fever with systemic illness, underlying conditions (COPD, heart disease, diabetes, asthma), recent hospitalization, or symptoms persisting beyond three weeks 5.