What are the treatment options for a dry cough?

Treatment of Dry Cough

For acute dry cough, start with honey and lemon mixtures, then escalate to dextromethorphan 60 mg for optimal cough suppression if needed. 1

Algorithmic Approach to Dry Cough Management

Step 1: Initial Non-Pharmacological Measures

• Begin with honey and lemon mixtures as the simplest, cheapest, and often effective first approach 1
• Encourage voluntary cough suppression techniques, which can reduce cough frequency in many cases 2
• Counsel smoking cessation immediately as smoking worsens cough symptoms 3

Step 2: First-Line Pharmacological Treatment

• Dextromethorphan is the preferred antitussive agent due to its superior safety profile compared to opioid alternatives 1, 4
• Dose at 60 mg for maximum cough reflex suppression with prolonged effect 1
• Standard over-the-counter dosing (typically 15-30 mg) is often subtherapeutic and inadequate 1
• Exercise caution with higher doses as some preparations contain additional ingredients like paracetamol 2

Step 3: Adjunctive Quick Relief

• Menthol inhalation provides acute but short-lived cough suppression through cold and menthol sensitive receptors 1
• Can be prescribed as menthol crystals, proprietary capsules, or lozenges 2
• Useful for immediate symptom relief while waiting for other treatments to take effect 1

Step 4: Nocturnal Cough Management

• First-generation sedating antihistamines are particularly suitable for nighttime cough that disrupts sleep 1
• The sedative properties provide dual benefit of cough suppression and improved sleep quality 2

Critical Pitfalls to Avoid

Medication Selection Errors

• Do not prescribe codeine-based antitussives - they have no greater efficacy than dextromethorphan but significantly more side effects including drowsiness, nausea, and constipation 1, 5
• Avoid using antitussives for productive cough where clearance of secretions is beneficial 1
• Do not use subtherapeutic doses of dextromethorphan (under 60 mg) expecting adequate relief 1

Inappropriate Antibiotic Use

• Antibiotics are not indicated for viral-induced dry cough, even if the patient feels unwell 3
• Diagnostic uncertainty often leads to inappropriate antibiotic prescribing, which should be avoided 3

Red Flags Requiring Medical Evaluation

Refer to physician immediately if any of the following are present: 3, 1

• Hemoptysis (coughing up blood)
• Breathlessness or dyspnea
• Prolonged fever with systemic illness
• Pre-existing conditions: COPD, heart disease, diabetes, asthma
• Recent hospitalization
• Symptoms persisting beyond 3 weeks

Special Clinical Scenarios

Post-Infectious Cough

• Consider inhaled ipratropium before central antitussives 1
• For severe paroxysms, short-course prednisone 30-40 mg daily may be beneficial 1
• If pertussis is suspected, macrolide antibiotics are indicated 1

Chronic Dry Cough (>3 weeks)

• Most commonly associated with post-viral syndrome, asthma, rhinosinusitis (post-nasal drip), or gastroesophageal reflux 6, 7
• ACE inhibitor use should be reviewed as a potential cause 6
• Enhanced cough reflex sensitivity is often present in these patients 6, 8
• Treatment success is considerably higher when managed in specialist cough clinics than general respiratory clinics 3

Evidence Quality Considerations

The guideline recommendations prioritize dextromethorphan over codeine based on safety profile rather than superior efficacy 1. However, it's important to note that there are no large-scale clinical trials of antitussive drugs in chronic cough patients - most studies have used capsaicin challenge protocols in healthy volunteers 3. Despite this limitation, the consistent evidence across guidelines supports the algorithmic approach outlined above for real-world clinical practice.