Liquid Antitussive Therapy for Viral Bronchitis
For an elderly female with viral bronchitis who can only tolerate liquids, prescribe liquid dextromethorphan as the first-line antitussive agent for short-term symptomatic cough relief. 1
Recommended Medication
Dextromethorphan liquid formulation is the optimal choice because:
- Available as an oral suspension/liquid that meets the patient's swallowing limitations 2
- Effective for chronic bronchitis cough suppression (40-60% reduction in cough counts), and while evidence is mixed for acute viral bronchitis, it is reasonable to presume efficacy 1
- Non-sedating compared to codeine, making it safer for elderly patients 1
- Available over-the-counter in extended-release formulations providing 12-hour relief 2
Alternative Option
Codeine liquid can be considered as a second-line agent if dextromethorphan fails:
- Supported by ACCP guidelines for chronic bronchitis with fair evidence 1
- More effective than dextromethorphan in some studies (40-60% cough suppression) 1
- However, carries greater adverse effect profile including sedation, constipation, and respiratory depression—particularly concerning in elderly patients 3, 4
- Requires prescription and careful monitoring 4
What NOT to Prescribe
Avoid the following medications:
- Expectorants (guaifenesin): No consistent favorable effect on cough in acute bronchitis; conflicting evidence and not recommended 1, 5
- Mucolytic agents: Not recommended for cough suppression in bronchitis 1
- Antibiotics: Not indicated for viral bronchitis; provide no benefit for cough and expose patients to unnecessary adverse effects 1, 6
Important Clinical Caveats
Duration expectations: Counsel the patient that viral bronchitis cough typically lasts 2-3 weeks regardless of treatment 7, 6. Antitussives provide only symptomatic relief with small/weak benefit (Grade C recommendation) 1.
Elderly-specific concerns: In elderly patients, be particularly cautious with:
- Codeine: Higher risk of sedation, falls, constipation, and respiratory depression 4
- Antihistamines: Not recommended due to anticholinergic effects in elderly 1
Red flags requiring further evaluation: Ensure this is truly viral bronchitis by ruling out:
- Pneumonia (check for fever >38°C, tachycardia >100 bpm, tachypnea >24 breaths/min, focal consolidation) 1
- Asthma or COPD exacerbation 1, 6
- Heart failure 6
Practical Prescribing
Dextromethorphan liquid: Start with standard over-the-counter formulations (e.g., 10-20 mg every 4-6 hours or extended-release 60 mg every 12 hours) 2. The extended-release suspension may be preferable for convenience and sustained relief 2.
If prescribing codeine liquid: Use lowest effective dose (typically 10-20 mg every 4-6 hours as needed) and monitor closely for adverse effects 4.