S91 A randomised, double-blind, placebo-controlled crossover study to assess the efficacy of a single dose of 100 mg of VRP700 by inhalation in reducing the frequency and severity of cough in adult patients with Idiopathic Pulmonary Fibrosis

The Therapeutic Landscape in Chronic Cough

In recent years, there has been a substantial increase in the development of antitussive therapies and the first new therapy, gefapixant has been licenced in Europe. This review describes current unlicenced treatments for chronic cough and details treatments currently in development for refractory chronic cough and cough in idiopathic pulmonary fibrosis, as well as compounds previously explored.

Mechanisms and management of cough in interstitial lung disease

INTRODUCTION

Many patients with interstitial lung diseases (ILDs), especially fibrotic ILDs, experience chronic cough. It negatively impacts both physical and psychological well-being. Effective treatment options are limited.

AREAS COVERED

The pathophysiology of chronic cough in IPF is complex and involves multiple mechanisms, including mechanical distortion of airways, parenchyma, and nerve fibers. The pathophysiology of cough in other fibrosing ILDs is poorly understood and involves various pathways. The purpose of this review is to highlight mechanisms of chronic cough and to present therapeutic evidence for its management in the most commonly occurring diffuse fibrosing lung diseases including idiopathic pulmonary fibrosis (IPF), connective tissue disease-related interstitial lung disease (CTD-ILD), sarcoidosis-related ILD (Sc-ILD), chronic hypersensitivity pneumonitis-related ILD (CHP-ILD), and post-COVID-19-related interstitial lung disease (PC-ILD).

EXPERT OPINION

This review guides the management of chronic cough in fibrosing ILDs. In this era of precision medicine, chronic cough management should be individualized in each interstitial lung disease.

Pharmacological and nonpharmacological interventions to improve symptom control, functional exercise capacity and quality of life in interstitial lung disease: an evidence synthesis

We assessed efficacy and effectiveness of pharmacological and nonpharmacological interventions in improving symptom control, functional exercise capacity and quality of life (QoL) in people living with fibrotic interstitial lung disease (ILD). We summarised evidence from three previous reviews (to June 2014) and conducted an updated search of nine databases and grey literature (2011-2019) (registration: CRD42017065933) for prospective studies of interventions aimed to alleviate symptoms, improve QoL or functional exercise capacity in fibrotic ILD. Data were synthesised through narrative synthesis or meta-analysed as appropriate. Forty-seven studies with 2527 participants were included. From 22 pharmacological studies of 11 different interventions (n=1683), the most tested interventions were bosentan and sildenafil. From 25 nonpharmacological studies, the most tested intervention was for pulmonary rehabilitation/exercise training (PR) (22 studies, n=748). There was an improvement in 6-min walk distance immediately following PR (six studies; n=200, mean difference (MD) (95% CI) 39.9 m (18.2 to 61.5)), but not longer term (3 or 6 months, four studies; n=147, MD 5.3 m (-12.9 to 23.4). Multiple, varied outcome measures were used (e.g. 37 studies assessing dyspnoea used 10 different scales with a lack of reporting of rate of deterioration in outcomes). Evidence gap mapping highlighted the most and least researched symptoms, as dyspnoea and cough, respectively. This evidence synthesis highlights overwhelmingly that the most researched symptom is dyspnoea and the strongest evidence base is for short-term PR. The least researched symptom was cough. Research going forward must focus on prioritising and standardising meaningful outcomes and focussing interventions on neglected symptoms.

A Randomized Controlled Trial to Assess the Effect of Lidocaine Administered via Throat Spray and Nebulization in Patients with Refractory Chronic Cough

BACKGROUND

Refractory chronic cough (RCC) is a debilitating condition for which there are no licensed treatments. Lidocaine is a nonselective inhibitor of voltage-gated sodium channels with potential antitussive effects, but randomized placebo-controlled studies evaluating its efficacy in RCC are lacking.

OBJECTIVE

To investigate the efficacy of nebulized lidocaine and lidocaine throat spray versus matched placebos in RCC.

METHODS

This was a randomized, double-blind, double-dummy, placebo-controlled, 3-way crossover study, comparing the effect of single doses of nebulized lidocaine with lidocaine delivered by a throat spray and matched placebo. The primary end point was cough frequency over the 10 hours following treatment. Secondary end points were visual analog scale scores for urge-to-cough and cough severity; an exploratory analysis evaluated hourly cough rates up to 5 hours after treatment.

RESULTS

Twenty-six subjects with RCC were recruited (22 females; mean age, 53.5 ± 12.1 years; FEV₁ %predicted, 105.2 ± 16.8 L; forced vital capacity %predicted, 112.4 ± 18 L). Lidocaine throat spray, but not nebulized lidocaine, significantly reduced 10-hour cough frequency as compared with placebo (throat spray, 22.6 coughs/h; nebulization, 26.9 coughs/h; and placebos, 27.6 coughs/h; P = .04,). Lidocaine throat spray showed the greatest effect on cough compared with placebo in the first hour after administration (31.7 coughs/h vs 74.2 coughs/h; P = .004). Both nebulizer and spray treatments significantly alleviated urge-to-cough and cough severity visual analog scale scores compared with placebo (P < .05). There were no serious adverse events associated with lidocaine therapy.

CONCLUSIONS

Lidocaine throat spray was effective in reducing cough frequency in patients with RCC. Voltage-gated sodium channel inhibitors applied to pharynx have potential as therapies for RCC.