Is there evidence for using gabapentin (neuropathic pain agent) for treating chronic cough in patients with bronchiectasis?

Gabapentin for Chronic Cough in Bronchiectasis

There is no evidence supporting the use of gabapentin for chronic cough specifically in patients with bronchiectasis based on current guidelines and available research.

Current Treatment Recommendations for Bronchiectasis-Related Cough

The management of chronic cough in bronchiectasis should focus on established therapeutic approaches:

1. Airway Clearance Techniques

   • Chest physiotherapy should be used in patients with mucus hypersecretion and difficulty expectorating 1
   • Referral to a respiratory physiotherapist is recommended to establish an optimal regimen 2
   • These techniques, while considered mainstays in treatment, have modest effects on increasing sputum volume 1

2. Antibiotic Therapy

   • For patients with ≥3 exacerbations per year, long-term antibiotics are recommended 2
   • Selection of antibiotics depends on bacterial colonization status:
     • For Pseudomonas aeruginosa: inhaled colistin (first-line) or gentamicin (second-line) 2
     • Without Pseudomonas: azithromycin or erythromycin 2
   • Antibiotics are the mainstay for treating exacerbations 1

3. Bronchodilators

   • Only recommended for patients with documented airflow obstruction or bronchial hyperreactivity 1, 2
   • Not recommended for routine use in all bronchiectasis patients 3
   • Despite limited evidence, they are commonly used in clinical practice 3

Gaps in Current Evidence

The management of chronic cough in bronchiectasis presents several challenges:

• Multiple cough mechanisms may be at play, including:

  • Productive cough due to mucus hypersecretion
  • Cough hypersensitivity syndrome
  • Complicating factors like post-nasal drip and gastroesophageal reflux 4

• Current guidelines do not address neurogenic or hypersensitivity components of chronic cough in bronchiectasis

• No specific mention of gabapentin or other neuromodulators for cough in bronchiectasis appears in the ACCP evidence-based clinical practice guidelines 1 or other recent guidelines 2

Clinical Approach to Chronic Cough in Bronchiectasis

1. First-line approaches:

   • Optimize airway clearance with chest physiotherapy 1, 2
   • Treat underlying infections with appropriate antibiotics 1, 2
   • Use bronchodilators if airflow obstruction is present 1, 3

2. For persistent cough despite optimal management:

   • Evaluate for comorbid conditions (GERD, post-nasal drip)
   • Consider referral to a multidisciplinary cough clinic
   • Consider trials of other established therapies before experimental approaches

Important Considerations

• The evidence base for bronchiectasis treatments overall is limited, with many recommendations based on expert opinion rather than high-quality RCTs 5, 6

• Most studies in bronchiectasis have small sample sizes (70% of trials included fewer than 40 participants) 6

• While gabapentin has been studied for refractory chronic cough in general, there are no specific studies examining its efficacy in the bronchiectasis population

• Potential side effects of gabapentin (dizziness, somnolence, fatigue) must be weighed against unproven benefits in this specific population

Conclusion

Based on current evidence, established treatments for bronchiectasis-related cough should be optimized before considering gabapentin. If standard treatments fail to control cough symptoms, referral to specialists with expertise in chronic cough management would be appropriate to consider experimental approaches like gabapentin on a case-by-case basis.