Nalbuphine Tablets for Cough in Patients with Idiopathic Pulmonary Fibrosis

Association of pruritus and chronic cough: an all of us database study

PURPOSE

Based on a potential shared pathophysiology tied to mast cell activity and neurogenic inflammation that may link pruritus and chronic cough (CC), this study, leveraging the All of Us database, examines the association between the two conditions.

MATERIALS AND METHODS

A nested case-control comparison was used to examine the association, identifying cases with SNOMED codes 418363000 (pruritus) and 68154008 (CC). Matching was performed on a 1:4 ratio by age, sex, and ethnicity using the MatchIt package in R, followed by maximum likelihood method to estimate odds ratios (ORs) and 95% confidence intervals from 2x2 contingency tables.

RESULTS

CC patients (n = 2,388) were more than twice as likely to be diagnosed with pruritus (OR: 2.65) and pruritus patients (n = 22,496) were more than twice as likely to be diagnosed with CC (OR: 2.57), than respective matched controls.

CONCLUSIONS

These results highlight the potential bidirectional relationship between CC and pruritus, suggesting possible shared immune and neural pathways. Treatments like difelikefalin and nalbuphine that modulate these pathways, alongside P2X3 targeting agents, are emerging as potential therapeutic approaches for itch and chronic cough given the possible interconnected pathophysiology. This study's insights into the associations between pruritus and CC may pave the way for targeted therapeutic strategies that address their shared mechanisms.

Precision medicine for respiratory diseases: A current viewpoint

In the realm of respiratory illnesses, despite the immense costs and efforts invested in diagnosis and treatment, numerous patients with chronic respiratory conditions or malignancies do not respond well to existing therapies. Delayed diagnoses and inadequate treatments contribute to these challenges, along with adverse reactions or treatment limitations due to side-effects. However, recent advancements in understanding respiratory diseases have paved the way for personalized medical treatments, considering individual genetic, molecular and environmental factors. Precision medicine, which accommodates individual differences in disease susceptibility and response to treatments, aims to improve patient care by aligning medical research with tailored therapies. Innovative technologies, such as genomic sequencing and biomarker identification contribute to this approach, allowing for customized treatments and the identification of effective therapies. Additionally, the application of precision medicine in lung cancer treatment exemplifies the forefront of individualized care within respiratory medicine. Several studies have explored the role of precision medicine in managing respiratory infectious diseases, asthma and idiopathic pulmonary fibrosis, aiming to categorize diseases more accurately and design targeted therapies. The ultimate goal is to enhance treatment effectiveness, minimize adverse events, and shift towards a patient-centered approach to managing respiratory conditions. Despite limitations, precision medicine holds promise for improving patient outcomes and emphasizing personalized care in respiratory medicine.

Interstitial Lung Disease: A Review

Importance

Interstitial lung disease (ILD) consists of a group of pulmonary disorders characterized by inflammation and/or fibrosis of the lung parenchyma associated with progressive dyspnea that frequently results in end-stage respiratory failure. In the US, ILD affects approximately 650 000 people and causes approximately 25 000 to 30 000 deaths per year.

Observations

The most common forms of ILD are idiopathic pulmonary fibrosis (IPF), which accounts for approximately one-third of all cases of ILD, hypersensitivity pneumonitis, accounting for 15% of ILD cases, and connective tissue disease (CTD), accounting for 25% of ILD cases. ILD typically presents with dyspnea on exertion. Approximately 30% of patients with ILD report cough. Thoracic computed tomography is approximately 91% sensitive and 71% specific for diagnosing subtypes of ILDs such as IPF. Physiologic assessment provides important prognostic information. A 5% decline in forced vital capacity (FVC) over 12 months is associated with an approximately 2-fold increase in mortality compared with no change in FVC. Antifibrotic therapy with nintedanib or pirfenidone slows annual FVC decline by approximately 44% to 57% in individuals with IPF, scleroderma associated ILD, and in those with progressive pulmonary fibrosis of any cause. For connective tissue disease-associated ILD, immunomodulatory therapy, such as tocilizumab, rituximab, and mycophenolate mofetil, may slow decline or even improve FVC at 12-month follow-up. Structured exercise therapy reduces symptoms and improves 6-minute walk test distance in individuals with dyspnea. Oxygen reduces symptoms and improves quality of life in individuals with ILD who desaturate below 88% on a 6-minute walk test. Lung transplant may improve symptoms and resolve respiratory failure in patients with end-stage ILD. After lung transplant, patients with ILD have a median survival of 5.2 to 6.7 years compared with a median survival of less than 2 years in patients with advanced ILD who do not undergo lung transplant. Up to 85% of individuals with end-stage fibrotic ILD develop pulmonary hypertension. In these patients, treatment with inhaled treprostinil improves walking distance and respiratory symptoms.

Conclusions and Relevance

Interstitial lung disease typically presents with dyspnea on exertion and can progress to respiratory failure. First-line therapy includes nintedanib or pirfenidone for IPF and mycophenolate mofetil for ILD due to connective tissue disease. Lung transplant should be considered for patients with advanced ILD. In patients with ILD, exercise training improves 6-minute walk test distance and quality of life.

Morphine for treatment of cough in idiopathic pulmonary fibrosis (PACIFY COUGH): a prospective, multicentre, randomised, double-blind, placebo-controlled, two-way crossover trial

BACKGROUND

Idiopathic pulmonary fibrosis is a progressive fibrotic lung disease, with most patients reporting cough. Currently, there are no proven treatments. We examined the use of low dose controlled-release morphine compared with placebo as an antitussive therapy in individuals with idiopathic pulmonary fibrosis.

METHODS

The PACIFY COUGH study is a phase 2, multicentre, randomised, double-blind, placebo-controlled, two-way crossover trial done in three specialist centres in the UK. Eligible patients aged 40-90 years had a diagnosis of idiopathic pulmonary fibrosis within 5 years, self-reported cough (lasting >8 weeks), and a cough visual analogue scale (VAS) score of 30 mm or higher. Patients were randomly assigned (1:1) to placebo twice daily or controlled-release morphine 5 mg orally twice daily for 14 days followed by crossover after a 7-day washout period. Patients were randomised sequentially to a sequence group defining the order in which morphine and placebo were to be given, according to a computer-generated schedule. Patients, investigators, study nurses, and pharmacy personnel were masked to treatment allocation. The primary endpoint was percentage change in objective awake cough frequency (coughs per h) from baseline as assessed by objective digital cough monitoring at day 14 of treatment in the intention-to-treat population, which included all randomised participants. Safety data were summarised for all patients who took at least one study drug and did not withdraw consent. This study was registered at ClinicalTrials.gov, NCT04429516, and has been completed.

FINDINGS

Between Dec 17, 2020, and March 21, 2023, 47 participants were assessed for eligibility and 44 were enrolled and randomly allocated to treatment. Mean age was 71 (SD 7·4) years, and 31 (70%) of 44 participants were male and 13 (30%) were female. Lung function was moderately impaired; mean forced vital capacity (FVC) was 2·7 L (SD 0·76), mean predicted FVC was 82% (17·3), and mean predicted diffusion capacity of carbon monoxide was 48% (10·9). Of the 44 patients who were randomised, 43 completed morphine treatment and 41 completed placebo treatment. In the intention-to-treat analysis, morphine reduced objective awake cough frequency by 39·4% (95% CI -54·4 to -19·4; p=0·0005) compared with placebo. Mean daytime cough frequency reduced from 21·6 (SE 1·2) coughs per h at baseline to 12·8 (1·2) coughs per h with morphine, whereas cough rates did not change with placebo (21·5 [SE 1·2] coughs per h to 20·6 [1·2] coughs per h). Overall treatment adherence was 98% in the morphine group and 98% in the placebo group. Adverse events were observed in 17 (40%) of 43 participants in the morphine group and six (14%) of 42 patients in the placebo group. The main side-effects of morphine were nausea (six [14%] of 43 participants) and constipation (nine [21%] of 43). One serious adverse event (death) occurred in the placebo group.

INTERPRETATION

In patients with cough related to idiopathic pulmonary fibrosis, low dose controlled-release morphine significantly reduced objective cough counts over 14 days compared with placebo. Morphine shows promise as an effective treatment to palliate cough in patients with idiopathic pulmonary fibrosis, and longer term studies should be the focus of future research.

FUNDING

The Jon Moulton Charity Trust.

Characterization of Codeine Treatment Responders Among Patients with Refractory or Unexplained Chronic Cough: A Prospective Real-World Cohort Study

PURPOSE

Codeine is a narcotic antitussive often considered for managing patients with refractory or unexplained chronic cough. This study aimed to evaluate the proportion and characteristics of patients who responded to codeine treatment in real-world practice.

METHODS

Data from the Korean Chronic Cough Registry, a multicenter prospective cohort study, were analyzed. Physicians assessed the response to codeine based on the timing and degree of improvement after treatment initiation. Follow-up assessments included the Leicester Cough Questionnaire and cough severity visual analog scale at six months. In a subset of subjects, objective cough frequency was evaluated following the initiation of codeine treatment.

RESULTS

Of 305 patients, 124 (40.7%) responded to treatments based on anatomic diagnostic protocols, while 181 (59.3%) remained unexplained or refractory to etiological treatments. Fifty-one subjects (16.7%) were classified as codeine treatment responders (those showing a rapid and clear response), 57 (18.7%) as partial responders, and 62 (20.3%) as non-responders. Codeine responders showed rapid improvement in objective cough frequency and severity scores within a week of the treatment. At 6 months, responders showed significantly improved scores in cough scores, compared to non-responders. Several baseline parameters were associated with a more favorable treatment response, including older age, non-productive cough, and the absence of heartburn.

CONCLUSIONS

Approximately 60% of chronic cough patients in specialist clinics may require antitussive drugs. While codeine benefits some, only a limited proportion (about 20%) of patients may experience rapid and significant improvement. This underscores the urgent need for new antitussive drugs to address these unmet clinical needs.

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.

A comprehensive comparison of the safety and efficacy of drugs in the treatment of idiopathic pulmonary fibrosis: a network meta-analysis based on randomized controlled trials

OBJECTIVE

Randomized controlled trials(RCTs) of multiple drugs for Idiopathic pulmonary fibrosis(IPF) have been reported and achieved a certain degree of efficacy, however, the difference in safety and efficacy of them for IPF is not yet well understood. The aim of this network meta-analysis is to assess their safety and efficacy in the treatment of IPF and differences in this safety and efficacy comprehensively.

METHODS

The PubMed, EMbase, CENTRAL and MEDLINE were retrieved to find out the RCTs of drugs in the treatment of IPF. The retrieval date is from construction to November 10, 2022. Stata 14.0 and RevMan 5.3 was used for statistical analysis.

REGISTRATION NUMBER

CRD42023385689.

RESULTS

Twenty-four studies with a total of 6208 patients were finally included, including RCTs of 13 drugs. The results of safety showed that there' s no difference in the incidence of SAEs of 13 drugs treated with IPF compared to placebo (P>0.05), and it's also found that Warfarin had a higher all-cause mortality for IPF than placebo (OR = 5.63, 95% CI [1.54 to 20.55]). SUCRA' s scatterplot showed that Pirfenidone, Nintedanib, Sildenafil and Imatinib were lower than placebo, and Warfarin, Ambrisentan and N-acetylcysteine were higher than placebo. The results of effectiveness showed that Nintedanib (MD = -0.08, 95% CI [-0.12 to -0.04]) improved FVC (L)absolute change from baseline in patients better than placebo, and Nintedanib (OR=1.81, 95% CI [1.23 to 2.66]), Pirfenidone (OR=1.85, 95%CI [1.26 to 2.71]) and Pamrevlumab (OR=4.11, 95% CI [1.25 to 13.58]) improved the proportion of patients with a decline in FVC ≥10% predicted better than placebo. SUCRA' s scatterplot showed that Pamrevlumab, Pirfenidone and Nintedanib were lower than placebo, and Warfarin and Ambrisentan were higher than placebo.

CONCLUSION

Compared with other drugs, Nintedanib and Pirfenidone can significantly slow the decline of lung function in patients with IPF, and the safety is higher. Therefore, they can be further promoted in clinical practice. Warfarin and Ambrisentan shouldn't be used clinically for IPF as the safety and efficacy of them are poor compared to other drugs and placebo. Pamrevlumab may become important drugs for the treatment of IPF in the future.

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.

Precision medicine advances in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a highly heterogeneous, unpredictable and ultimately lethal chronic lung disease. Over the last decade, two anti-fibrotic agents have been shown to slow disease progression, however, both drugs are administered uniformly with minimal consideration of disease severity and inter-individual molecular, genetic, and genomic differences. Advances in biological understanding of disease endotyping and the emergence of precision medicine have shown that "a one-size-fits-all approach" to the management of chronic lung diseases is no longer appropriate. While precision medicine approaches have revolutionized the management of other diseases such as lung cancer and asthma, the implementation of precision medicine in IPF clinical practice remains an unmet need despite several reports demonstrating a large number of diagnostic, prognostic and theragnostic biomarker candidates in IPF. This review article aims to summarize our current knowledge of precision medicine in IPF and highlight barriers to translate these research findings into clinical practice.

Unravelling vagal hypersensitivity in chronic cough: A distinct disease

Chronic cough (CC) is a common but poorly understood disease that has a negative impact on quality of life. For years, clinicians have been trying to find the underlying diagnosis and using existing disease models to describe the patients' illness. This presents a confusing picture of CC. Most patients with CC present with hypersensitivity of the cough reflex, which is characterised by laryngeal paraesthesia and an increased response to the tussive stimuli or an innocuous stimulus that would not trigger coughing in healthy people. Recently, it has been proposed that CC is a unique disease characterised by vagal hypersensitivity that projects to the central nervous system altering responsiveness. The evidence supports the hypothesis that CC is primarily a neurological disorder, consisting of different phenotypes.

Managing Chronic Cough Associated with Idiopathic Pulmonary Fibrosis - Will Nalbuphine Fill an Unmet Need?

In this issue of NEJM Evidence, Maher et al.1 report the results of a randomized, controlled, 22-day treatment crossover trial comparing the antitussive effect of extended-release nalbuphine, an opioid agonist-antagonist, with placebo in a cohort of patients with definite or probable idiopathic pulmonary fibrosis (IPF). In this small, short-term trial of 38 evaluable patients, the active drug was associated with a 75.1% reduction in daytime objective cough frequency (the primary outcome) compared with a 22.6% reduction in placebo-treated patients, yielding a substantial and statistically significant 52.5 percentage point placebo-adjusted change from baseline.