What is the treatment for chronic dry cough secondary to underlying Interstitial Lung Disease (ILD)?

From the Guidelines

Treatment of chronic dry cough secondary to underlying interstitial lung disease (ILD) should prioritize addressing the underlying ILD with immunosuppressive or antifibrotic medications, alongside symptomatic cough management with neuromodulators like gabapentin or pregabalin, as recommended by the most recent guidelines 1. The primary treatment involves addressing the underlying ILD, and according to the 2023 American College of Rheumatology (ACR)/American College of Chest Physicians (CHEST) guideline for the treatment of interstitial lung disease in people with systemic autoimmune rheumatic diseases, mycophenolate, azathioprine, rituximab, and cyclophosphamide are conditionally recommended as first-line ILD treatment options for people with SARD-ILD 1. For symptomatic cough management, consider gabapentin starting at 300 mg daily and titrating up to 300 mg three times daily over 1-2 weeks, or pregabalin starting at 75 mg twice daily and increasing to 150-300 mg twice daily as needed, as suggested by the CHEST guideline and expert panel report 1. Low-dose opioids like codeine (15-30 mg every 4-6 hours) or hydrocodone may be used for refractory cases, with careful monitoring of side effects and cough severity 1. Inhaled corticosteroids such as fluticasone (250-500 mcg twice daily) can help if there's an inflammatory component, but their use should be tailored to the specific ILD diagnosis and presence of inflammation 1. Proton pump inhibitors like omeprazole (20-40 mg daily) should be added if gastroesophageal reflux contributes to the cough, although their use is not universally recommended for all ILD patients with cough 1. Pulmonary rehabilitation, oxygen therapy for hypoxemia, and treatment of comorbidities are important adjunctive measures to improve quality of life and reduce morbidity and mortality in patients with ILD and chronic cough. These treatments work by reducing inflammation, slowing fibrosis progression, and modulating neural hypersensitivity in cough reflex pathways, ultimately improving morbidity, mortality, and quality of life outcomes for patients with ILD and chronic cough. Regular monitoring of medication side effects and cough severity is essential for optimal management, and treatment should be individualized based on the specific ILD diagnosis, cough severity, and patient comorbidities.

From the Research

Treatment of Chronic Dry Cough Secondary to Underlying Interstitial Lung Disease (ILD)

• The treatment of chronic dry cough in patients with interstitial lung disease (ILD) is complex and often challenging, with limited effective treatment options available 2, 3.
• The pathophysiology of cough in ILD is multifactorial, involving neural hypersensitivity, structural lung changes, inflammatory processes, and comorbid conditions such as gastroesophageal reflux disease (GERD) 2.
• Management strategies for chronic cough in ILD include pharmacological interventions, such as neuromodulators, antifibrotic agents, and pharmacologic and surgical GERD treatments, as well as non-pharmacological approaches like behavioral therapies, cough suppression techniques, and pulmonary rehabilitation and physiotherapy 2, 3.
• Emerging treatments, such as P2X3 receptor antagonists and airway hydration therapies, offer promising avenues but require further investigation through robust clinical trials 2.
• Clinicians should be cautious when ascribing chronic cough to ILD without first completely evaluating for other possible causes of cough, such as asthma, upper airway cough syndrome, or GERD 4.
• Corticosteroids may be helpful in alleviating chronic cough in some cases of ILD, but treatment should weigh the risks and benefits for each patient individually 4.
• Nonspecific antitussive therapies, such as codeine and dextromethorphan, have been shown to be clinically effective for chronic cough in general, but their efficacy in ILD has not been specifically studied 4.
• A high prevalence of non-ILD causes of cough has been recorded in patients with ILD, highlighting the need for a thorough evaluation of cough triggers and mechanisms 5.
• Patients with ILD often adopt their own strategies to control their cough, including avoidance of triggers, and report moderate benefit from various medications, including anti-fibrotics, immunosuppression drugs, inhalers, and proton pump inhibitors 5.

Mechanisms of Cough in ILD

• The mechanisms of chronic cough in ILD are not fully understood and are likely to involve multiple pathways, including mechanical distortion of airways, parenchyma, and nerve fibers 3.
• The pathophysiology of cough in different ILD subtypes, such as idiopathic pulmonary fibrosis (IPF), connective tissue disease-related ILD (CTD-ILD), sarcoidosis-related ILD (Sc-ILD), chronic hypersensitivity pneumonitis-related ILD (CHP-ILD), and post-COVID-19-related interstitial lung disease (PC-ILD), may vary 3.
• Further research is needed to elucidate the complex pathways involved in the pathogenesis of chronic cough in ILD and to identify new therapeutic agents to alleviate this distressing and often intractable symptom 6.

Evaluation and Assessment of Cough in ILD

• Evaluating cough in ILD relies on subjective and objective tools to measure its severity, frequency, and impact on daily life, although standardization of these measures remains challenging 2.
• The Leicester cough questionnaire is a validated tool that can be used to assess cough severity and impact on quality of life in patients with ILD 5.
• A visual analogue scale can also be used to assess cough severity and impact on quality of life in patients with ILD 5.