Chronic cough in idiopathic pulmonary fibrosis: what can be done?

Stuart* stopped in his tracks and stooped over. A barking cough shook his entire frame. The bullish sound exploded down the hospital corridor. He shrank back in embarrassment, looking at me apologetically, face flushed from exertion. We had just arrived at the respiratory outpatient’s department for his first clinical trial visit.

For the past six months, I’ve been co-ordinating a study. Stuart was the first participant recruited to our site. Only 57 years old, he was willing and eager for any possibility of relieving his most incessant symptom.

What is idiopathic pulmonary fibrosis?

Idiopathic pulmonary fibrosis is a chronic, fibrosing interstitial lung disease of unknown origin.^[1] It is a progressive, incurable disease characterised by breathlessness and worsening lung function over time.^[1]  Cough is often present, with or without sputum.^[1] The median survival time is approximately three years from diagnosis, but the rate of deterioration varies significantly from person to person.^[1]

The intrusion of cough in idiopathic pulmonary fibrosis

Cough is debilitating for many people living with IPF. In one longitudinal study consisting of 242 participants, 84% reported cough as their main symptom.^[2] The study also found that cough is a predictor of disease progression, independent of the disease severity.^[2]

Chronic cough is a severely distressing symptom, with the frequency of cough correlating to a significant reduction in quality of life.^[3] Cough impacts every part of a person’s well-being, from the social stigmatisation found post COVID-19, to physical symptoms such as air hunger, fatigue, anxiety and psychological distress.^[4]

A chronic cough is identified as a cough lasting a minimum of eight weeks.^[5] For people living with IPF, cough rate is worse than the healthy population or people with asthma.^[6]

Chronic cough can also be attributable to other comorbidities commonly associated with IPF, such as gastroesophageal reflux disease (GERD), obstructive sleep apnoea, or asthma.^[4],[7] Achieving a correct diagnosis of the underlying physiology of cough is therefore essential. Screening for other risk factors, and determining the severity, duration and frequency of a person’s cough helps us to establish aetiology and guide the treatment options we discuss with patients.

Current treatments for idiopathic pulmonary fibrosis

There is, of yet, no known cure for IPF.^[8] The current mainstays of therapy consist of two anti-fibrotic drugs.^[7] These work to slow disease progression and decrease in lung function.^[9],[10] However, in my experience in clinics, not all patients tolerate these drugs well, with some experiencing side effects such as nausea, migraines and photosensitivity.^[11],[12]

Antacids are sometimes prescribed for cough in IPF, but recent recommendations advise against their use for the sole purpose of improving respiratory outcomes.^[13]

Neuromodulators are also prescribed, with some evidence to show they can increase cough-related quality of life.^[14]

Based on evidence from treatment of refractory chronic cough, morphine is also being used as a therapeutic agent, with a current study underway to investigate its effects.^[15]

Hope for the future?

The mechanisms of cough in IPF are complex. The study I am currently coordinating is one amongst several clinical trials investigating different therapeutic targets involved in the hypersensitive cough reflex. Certainly more research needs to be done to understand the fibrotic and neurological processes associated with cough in IPF to relieve this burdensome symptom.

For Stuart, a lung transplant is now his only option. He uses ambulatory oxygen and is breathless on the slightest exertion. As his research nurse, I’ve accompanied him throughout his clinical trial journey, and witnessed the devastating impact of this disease. My hope is that as new treatments are engineered, and our understanding of the pathogenesis of IPF cough develops, effective treatments, and ultimately a cure, will be found.

Meanwhile Stuart, alongside all participants who take part in research, has made an invaluable contribution to the future health of generations to come. It will not be forgotten.

*names have been changed to protect privacy. 

Any advice given and opinions expressed in this article are those of the author and do not reflect the view of Chiesi Limited (Chiesi).  All content in this article is for informational and educational purposes only.  Although Chiesi strives to always provide accurate information, it is not responsible for and does not verify for accuracy any of the information contained within.

[1] NICE. Idiopathic pulmonary fibrosis in adults: diagnosis and management. Available at: https://www.nice.org.uk/guidance/cg163/chapter/Introduction

[2] Ryerson CJ, Abbritti M, Ley B, et al. Cough predicts prognosis in idiopathic pulmonary fibrosis. Respirology. 2011; 16(6): 969-75

[3] Lee J, White E, Freiheit E et al. Cough-Specific Quality of Life Predicts Disease Progression Among Patients With Interstitial Lung Disease. Chest. 2022; 162(3): 603-613

[4] Wakwaya, Y, Ramdurai, D and Swigris, J. Managing cough in idiopathic pulmonary fibrosis. Chest. 2021; 160(5): 1774–1782

[5] Irwin R, French C, Chang A, et al. Classification of Cough as a Symptom in Adults and Management Algorithms: CHEST Guideline and Expert Panel Report. Chest. 2018; 153(1): 196-209

[6] Key, A, Holt K, Hamilton A, et al. Objective Cough Frequency in Idiopathic Pulmonary Fibrosis. Cough. 2010; 6: 4

[7] Chung, K, Birring, S, Morice, A et al. Tackling the Neuropathic Cough of Idiopathic Pulmonary Fibrosis (IPF): More Needs to be Done. Lung. 2022; 200: 673–675

[8] NHS. Idiopathic pulmonary fibrosis. Available at: https://www.nhs.uk/conditions/idiopathic-pulmonary-fibrosis/

[9] Krauss E, Tello S, Wilhelm J, et al. Assessing the Effectiveness of Pirfenidone in Idiopathic Pulmonary Fibrosis: Long-Term, Real-World Data from European IPF Registry (eurIPFreg). J Clin Med. 2020; 9(11): 3763

[10] Khan MA, Sherbini N, Alyami S, et al. Nintedanib and pirfenidone for idiopathic pulmonary fibrosis in King Abdulaziz Medical City, Riyadh: Real-life data. Ann Thorac Med. 2023; 18(1): 45-51

[11] EMC. Healthcare Professionals (SmPC). Available at: https://www.medicines.org.uk/emc/product/2731/smpc#about-medicine

[12] EMC. Healthcare Professionals (SmPC). Available at: https://www.medicines.org.uk/emc/product/7705/smpc

[13] Raghu G, Remy-Jardin M, Richeldi L et al. Idiopathic Pulmonary Fibrosis (an Update) and Progressive Pulmonary Fibrosis in Adults: An Official ATS/ERS/JRS/ALAT Clinical Practice Guideline. Am J Respir Crit Care Med. 2022; 205(9): e18-e47

[14] Wei W, Liu R, ZhangTong Y, Qiu Z. The efficacy of specific neuromodulators on human refractory chronic cough: a systematic review and meta-analysis. J Thorac Dis. 2016; 8(10): 2942-2951

[15] Wu, Z, Banya, W, Chaudhuri, N et al. PAciFy Cough—a multicentre, double-blind, placebo-controlled, crossover trial of morphine sulphate for the treatment of pulmonary Fibrosis Cough. Trials. 2022; 23(1): 184