What is the recommended treatment for a dry cough?

Treatment of Dry Cough

Start with simple home remedies like honey and lemon as first-line treatment, then use dextromethorphan 60 mg (not the standard 30 mg dose) if pharmacological therapy is needed, as it provides superior cough suppression with fewer side effects than codeine-based alternatives. 1, 2

First-Line Non-Pharmacological Approach

• Simple home remedies such as honey and lemon are the simplest, cheapest, and often as effective as pharmacological treatments for benign viral cough 1, 2
• Voluntary suppression of cough through central modulation may be sufficient to reduce cough frequency in some patients 1, 2
• Acute viral cough is typically benign and often does not require prescribed medication 1

Pharmacological Treatment Algorithm

Primary Pharmacological Option: Dextromethorphan

Dextromethorphan is the preferred antitussive due to its superior safety profile compared to opioid alternatives 1, 2, 3

• Use 60 mg for maximum cough reflex suppression, as standard over-the-counter dosing (30 mg) is often subtherapeutic 1, 2
• A dose-response relationship exists with maximum suppression at 60 mg 1
• Dextromethorphan is a non-sedating opiate that acts centrally to suppress the cough reflex 2
• Meta-analysis has shown effectiveness for acute cough 1

Critical caveat: Exercise caution with higher doses as some combined preparations contain additional ingredients like paracetamol that could lead to toxicity 1, 2

Alternative Options for Specific Situations

For nocturnal cough disrupting sleep:

• First-generation antihistamines with sedative properties can suppress cough and are particularly useful due to their sedative effects at night 1, 2
• The drowsiness is actually valuable when cough is disturbing sleep 4

For quick but temporary relief:

• Menthol by inhalation suppresses cough reflex acutely but provides short-lived effect 1, 2
• Can be prescribed as menthol crystals or proprietary capsules 1

What NOT to Use

Codeine and pholcodine are not recommended 1, 2

• They have no greater efficacy than dextromethorphan 1, 2
• They carry a significantly worse adverse side effect profile including drowsiness, nausea, constipation, and physical dependence 1, 2, 5
• Despite codeine being the most researched drug in this field, it is less preferred due to greater side effects 6

Red Flags Requiring Further Evaluation

Before treating symptomatically, assess for conditions requiring specific treatment:

• Cough with increasing breathlessness suggests possible asthma or anaphylaxis 1
• Cough with fever, malaise, or purulent sputum may indicate serious lung infection 1
• Significant hemoptysis or possible foreign body inhalation requires specialist referral 1
• Cough lasting more than 7 days, recurring cough, or cough with fever, rash, or persistent headache could indicate serious underlying conditions 3

Persistent Dry Cough Considerations

If cough persists beyond acute viral illness, consider underlying causes:

• GORD (gastroesophageal reflux disease) may require intensive acid suppression with proton pump inhibitors for at least 3 months 1
• Reflux-associated cough may occur without gastrointestinal symptoms—a common pitfall in diagnosis 1
• Upper airway symptoms warrant a trial of topical corticosteroid 1
• Smoking cessation should be encouraged as it leads to significant remission in cough symptoms 1
• Bronchial provocation testing should be performed in patients with chronic cough and normal spirometry without obvious cause 1

Contraindications and Warnings

• Do not use dextromethorphan if currently taking MAOIs or within 2 weeks of stopping MAOI therapy 3
• Contains sodium metabisulfite which may cause allergic-type reactions in susceptible individuals 3
• Do not use for chronic cough associated with smoking, asthma, or emphysema without medical evaluation 3
• Do not use for productive cough with excessive phlegm 3

Common Pitfalls to Avoid

• Using subtherapeutic doses of dextromethorphan (30 mg instead of 60 mg) that may not provide adequate relief 1, 2
• Prescribing codeine-based antitussives which have no efficacy advantage but increased side effects 1, 2
• Failing to consider GORD as a cause for persistent cough 1
• Not recognizing that reflux-associated cough may occur without gastrointestinal symptoms 1