What is the best treatment approach for a patient with a non-productive cough, potentially with a history of asthma or Chronic Obstructive Pulmonary Disease (COPD)?

Treatment of Non-Productive Cough

For non-productive cough, begin with a systematic diagnostic approach targeting the three most common causes—upper airway cough syndrome (UACS), asthma, and gastroesophageal reflux disease (GERD)—treating each sequentially and additively, as multiple causes frequently coexist. 1

Initial Assessment and Red Flags

Before initiating treatment, identify whether the patient is:

• Taking an ACE inhibitor (stop immediately and replace if present) 1
• A current smoker (counsel on cessation as priority) 1
• Showing signs of serious illness: hemoptysis, significant breathlessness, prolonged fever, weight loss, or night sweats (requires chest X-ray and advanced evaluation) 2, 3

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

Start with a first-generation antihistamine-decongestant combination (e.g., brompheniramine/pseudoephedrine or chlorpheniramine/phenylephrine) as initial empiric therapy. 1, 3

• Expected response time: days to 1-2 weeks 3
• This addresses post-nasal drip and upper airway inflammation, the most common cause of chronic non-productive cough 1, 4
• Add intranasal corticosteroid spray (fluticasone or mometasone) for enhanced upper airway control 3

Second-Line Treatment: Asthma or Non-Asthmatic Eosinophilic Bronchitis (NAEB)

If cough persists after treating UACS, evaluate for asthma next, ideally with bronchoprovocation challenge testing; if unavailable, initiate empiric trial of inhaled corticosteroids with beta-agonists. 1

• Medical history alone is unreliable for ruling in or out asthma as a cause 1
• Combination therapy: inhaled corticosteroids (fluticasone 220 mcg or budesonide 360 mcg twice daily) plus inhaled beta-agonists 1, 3
• Expected response time: up to 8 weeks 3
• Critical pitfall: Albuterol alone is NOT recommended for chronic cough not due to asthma 1

Third-Line Treatment: Gastroesophageal Reflux Disease (GERD)

If cough persists despite treatment for UACS and asthma, initiate high-dose proton pump inhibitor therapy (omeprazole 40 mg twice daily) with dietary modifications. 1, 3

• GERD can cause cough even without typical gastrointestinal symptoms ("silent GERD") 3
• Expected response time: 2 weeks to several months 3
• Continue previous treatments while adding GERD therapy, as causes are frequently multifactorial 3

Symptomatic Antitussive Therapy

For Chronic Bronchitis or COPD-Related Cough:

Central cough suppressants (codeine or dextromethorphan) are recommended for short-term symptomatic relief. 1

• Dextromethorphan 60 mg provides maximum cough reflex suppression 2
• Standard over-the-counter doses are subtherapeutic 2
• Use sugar-free formulations for diabetic patients 2

For Post-Infectious Cough:

Inhaled ipratropium bromide (2-3 puffs four times daily) has the strongest evidence for attenuating post-infectious cough. 3

• Expected response: 1-2 weeks 3
• Guaifenesin (200-400 mg every 4 hours) is appropriate for initial supportive care 3, 5

Peripheral Cough Suppressants:

Levodropropizine and moguisteine are recommended for short-term symptomatic relief with substantial benefit, particularly in children. 1, 6

Critical Pitfalls to Avoid

• Never prescribe antibiotics for non-productive cough unless clear evidence of bacterial infection exists 2, 3
• Do not use central cough suppressants (codeine, dextromethorphan) for upper respiratory infection-related cough—they have limited efficacy 1
• Avoid suppressing productive cough in conditions like pneumonia or bronchiectasis where clearance is important 1
• Do not use manually assisted cough in patients with COPD or airflow obstruction—it may be detrimental 1
• Sequential and additive therapy is essential: Continue effective treatments while adding next intervention rather than stopping and switching 1, 3

Special Considerations for Asthma/COPD Patients

In patients with known asthma or COPD experiencing non-productive cough:

• Optimize existing controller medications first 3
• Evaluate for exacerbation triggers or inadequate disease control 1
• Consider inhaled corticosteroids if not already prescribed 1, 3
• Huffing techniques should be taught as adjunct for sputum clearance in COPD and CF 1

When to Refer to Specialist

Refer to a cough specialist if cough remains undiagnosed after systematically addressing UACS, asthma/NAEB, and GERD, or if cough persists beyond 8 weeks despite appropriate treatment. 1, 3

• Consider high-resolution CT chest and bronchoscopy if all empiric therapies fail 3
• Idiopathic chronic cough may require low-dose morphine, baclofen, or nebulized local anesthetics under specialist guidance 1