What is the first line of treatment for a patient with a dry cough that worsens at rest?

Treatment for Dry Cough That Worsens at Rest

For a patient with dry cough that worsens at rest, start with honey and lemon mixtures as the simplest first-line approach, followed by dextromethorphan 30-60 mg if additional relief is needed. 1, 2

First-Line Treatment Approach

Non-Pharmacologic Options

• Honey and lemon mixtures are the simplest, cheapest, and often effective first approach for dry cough 1, 2
• Simple voluntary suppression of cough may be sufficient to reduce cough frequency in many cases 1
• Adequate hydration helps thin secretions 1

Pharmacologic First-Line: Dextromethorphan

• Dextromethorphan is the recommended first-line antitussive agent due to its superior safety profile compared to opioid alternatives 2, 3
• Optimal dosing is 60 mg for maximum cough reflex suppression with prolonged effect 1, 2
• Standard over-the-counter dosing (often 10-30 mg) is frequently subtherapeutic 2
• This is a non-sedating opiate that has been shown to suppress cough in meta-analysis 1
• Important caveat: Care must be taken with higher doses as some preparations contain other ingredients like paracetamol 1
• FDA warning: Do not use if taking MAOIs or within 2 weeks of stopping them 3

Additional First-Line Options

• Menthol by inhalation provides acute, short-lived cough suppression through the cold and menthol sensitive receptor (CMR1) 1, 2
• Can be prescribed as menthol crystals or proprietary capsules/lozenges 1
• Particularly useful for quick but brief relief 2

Second-Line Treatment Options

For Nocturnal Cough

• First-generation antihistamines with sedative properties (like chlorpheniramine) can suppress cough 1, 2, 4
• May be particularly suitable for nocturnal cough due to their sedating effect, which is valuable if cough is disturbing sleep 1, 4

What NOT to Use

Codeine and Pholcodine

• Codeine or pholcodine have no greater efficacy than dextromethorphan but have a much greater adverse side effect profile and are not recommended 1, 2
• Despite being widely regarded as the standard cough suppressant, codeine may have efficacy to suppress cough in humans only in specific situations 5
• Caution is needed to limit its use only when and as long as clinically necessary, particularly in children 5

Special Considerations for "Cough That Worsens at Rest"

Since the cough worsens at rest, consider:

• Postural relationship may suggest gastroesophageal reflux disease (GERD) as an underlying cause 6
• Nocturnal worsening makes sedating antihistamines particularly appropriate as second-line therapy 1, 4
• If this is a postinfectious cough (following acute respiratory infection within 3-8 weeks), consider inhaled ipratropium before central antitussives 6, 2

Red Flags Requiring Immediate Medical Attention

Seek medical evaluation if any of the following are present:

• Coughing up blood 6, 1
• Breathlessness, especially at rest or at night 6, 1
• Prolonged fever and feeling unwell 6, 1
• Underlying conditions like COPD, heart disease, diabetes, or asthma 6, 1
• Recent hospitalization 6, 1
• Symptoms persisting for more than 3 weeks 6, 1, 2
• Hoarseness, systemic symptoms, weight loss, or peripheral edema 6

Common Pitfalls to Avoid

• Using subtherapeutic doses of dextromethorphan (standard OTC doses of 10-30 mg) that may not provide adequate relief—use 60 mg for optimal effect 1, 2
• Prescribing codeine-based antitussives which have no efficacy advantage but increased side effects 1, 2
• Not stopping smoking, which worsens cough and respiratory symptoms 6, 1
• Failing to consider underlying causes like GERD, asthma, or upper airway cough syndrome that may require specific treatment 6

Practical Treatment Algorithm

1. Start with honey and lemon mixtures 1, 2
2. If inadequate relief, add dextromethorphan 60 mg 1, 2
3. For nocturnal symptoms, consider sedating antihistamines 1, 2, 4
4. For quick but brief relief, add menthol inhalation 1, 2
5. If symptoms persist beyond 3 weeks or red flags present, seek medical evaluation to investigate underlying causes 6, 1