Is Benzonatate Safe in COPD?
Benzonatate can be used cautiously in COPD patients, but it requires careful assessment of respiratory status and should not be combined with benzodiazepines or opioids due to additive respiratory depression risks. 1
Primary Safety Concerns
The main theoretical risk with benzonatate in COPD relates to its local anesthetic properties, which could worsen respiratory function in patients with severe hypoxia or hypercapnia. 1 This concern is most relevant in advanced COPD with significant gas exchange abnormalities rather than mild-to-moderate disease.
When Benzonatate May Be Appropriate
Limited evidence suggests benzonatate can be effective for cough control in respiratory disease:
- In lung cancer patients (who often have concurrent COPD), benzonatate effectively controlled cough in 80% of cases in one case series, including patients unresponsive to opioids. 2
- The drug works peripherally by anesthetizing stretch receptors in the respiratory tract, avoiding the central respiratory depression seen with opioid antitussives. 2
Critical Contraindications and Drug Interactions
Absolute avoidance: Do not combine benzonatate with benzodiazepines or opioids in COPD patients, as this creates dangerous additive respiratory depression. 1 This is particularly important given that:
- Benzodiazepines are commonly prescribed in COPD (31.7% of older adults with COPD receive them), despite causing increased drowsiness, COPD exacerbations, and respiratory infections. 3, 4
- Opioids should be reserved only for terminal COPD patients with refractory dyspnea. 1
Recommended Clinical Algorithm
Step 1: Optimize COPD maintenance therapy first before considering any cough suppressant. 1
- Ensure patients are on appropriate long-acting bronchodilators (LAMA preferred over LABA for reducing exacerbations). 1
- Consider LAMA/LABA combinations for better symptom control. 1
Step 2: Assess current respiratory status before prescribing benzonatate. 1
- Check for severe hypoxia or hypercapnia (contraindications). 1
- Evaluate FEV1 and recent exacerbation history.
Step 3: If benzonatate is prescribed:
- Use lowest effective dose for shortest duration.
- Verify patient is not taking benzodiazepines or opioids. 1
- Add non-pharmacologic measures (coughing techniques, forced expiratory maneuvers, pursed-lip breathing). 1
Alternative Cough Management
For chronic bronchitis-related cough in COPD, codeine and dextromethorphan have demonstrated 40-60% reduction in cough counts, though studies were small. 2 However, these centrally-acting agents carry their own respiratory depression risks.
For acute exacerbations: Short-acting beta-agonists or anticholinergic bronchodilators are first-line, not antitussives. 2
Key Pitfalls to Avoid
- Do not prescribe benzonatate during acute COPD exacerbations when respiratory compromise is greatest.
- Screen medication lists carefully for concurrent CNS depressants before prescribing. 1
- Avoid in patients with history of pneumothorax or emphysematous bullae (similar precautions as with other respiratory-affecting agents). 5
- Remember that cough may improve simply by optimizing bronchodilator therapy, making antitussives unnecessary. 1