Comparable effect of a leukotriene receptor antagonist and long-acting beta₂-adrenergic agonist in cough variant asthma

Efficacy and Safety of Yukmijihwang-Tang in the Treatment of Cough-Variant Asthma: Study Protocol for a Phase 2, Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial

BACKGROUND

Cough-variant asthma (CVA), a precursor of typical asthma, is the main cause of chronic cough. We hypothesize that yukmijihwang-tang (YJT), which has been used for chronic cough in traditional medicine and has been reported to have an anti-inflammatory effect, could be an adjuvant to asthma treatment.

METHODS

We plan a randomized, double-blind, placebo-controlled, multicenter, phase 2 trial to investigate the efficacy and safety of YJT in CVA patients. A total of 60 patients with CVA will be recruited and randomly assigned to either a high-dose YJT group, standard-dose YJT group, or control group (placebo) in a 1:1:1 allocation ratio after a 2-week run-in period. For the run-in period, only inhaled corticosteroids (ICSs) will be used, and the investigational drug will be administered once a day with concomitant ICS for 6 weeks. Data will be collected at baseline, week 3, and week 6, and the primary outcome measure will be the mean cough symptom score (CSS) change before and after medication. The secondary outcome measures will include the Leicester cough questionnaire-Korean version (LCQ-K) score, eosinophil count and eosinophil cationic protein level, pulmonary function test, and the number of uses of rescue medication, and so on.

CONCLUSION

This study aimed to evaluate the efficacy and safety of YJT in concomitant treatment with ICS in patients with CVA and to determine the optimal dosage of YJT. The results are expected to provide evidence for the use of YJT as an adjuvant treatment for CVA.

Hintergrund

Cough-Variant-Asthma (CVA), eine Frühform von typischem Asthma, ist die Hauptursache von chronischem Husten. Unserer Vermutung nach könnte Yukmijihwang-Tang (YJT), das in der traditionellen Medizin zur Behandlung von chronischem Husten eingesetzt wird und das Berichten zufolge einen entzündungshemmenden Effekt hat, unterstützend in der Asthma-Therapie wirken.

Method

en: Wir planen eine randomisierte, doppelblinde, placebokontrollierte, multizentrische Phase-2-Studie, um die Wirksamkeit und Sicherheit von YJT bei Patienten mit CVA zu untersuchen. Insgesamt werden 60 CVA-Patienten für die Studie rekrutiert und nach einer zweiwöchigen Run-in-Phase randomisiert im Verhältnis 1:1:1 einer Gruppe mit hochdosiertem YJT, einer Gruppe, die YJT in der Standarddosierung erhält oder einer Kontrollgruppe (Placebo) zugewiesen. Während der Run-in-Phase werden nur inhalative Corticosteroide (ICS) verwendet, und das Prüfpräparat wird über 6 Wochen einmal täglich gleichzeitig mit den ICS angewendet. Die Datenerhebung erfolgt bei Studienbeginn, in Woche 3 sowie in Woche 6, und das primäre Zielkriterium ist die Änderung des mittleren Hustenscores (cough symptom score, CSS) vor und nach der Anwendung der Medikamente. Zu den sekundären Zielkriterien gehören der Score des Leicester Hustenfragebogens - koreanische Version (LCQ-K), die Eosinophilenzahl und der Spiegel an eosinophilem kationischen Protein, Lungenfunktionstests sowie die Anzahl der Anwendungen von Bedarfsmedikation usw.

Schlussfolgerung

Ziel dieser Studie ist es, die Wirksamkeit und Sicherheit von YJT bei gleichzeitiger Behandlung mit ICS bei Patienten mit CVA zu bewerten und die optimale YJT-Dosis zu ermitteln. Es wird erwartet, dass die Ergebnisse Belege für die Anwendung von YJT als adjuvante Therapie bei CVA liefern werden.

Registrierung der Studie

WHO International Clinical Trials Registry Platform, Clinical Research Information Service (CRIS), KCT0006994, registriert am 10. Februar 2022, https://cris.nih.go.kr/cris/search/detailSearch.do/21743.

Narrative Review of the Mechanisms and Treatment of Cough in Asthma, Cough Variant Asthma, and Non-asthmatic Eosinophilic Bronchitis

Chronic cough is a debilitating condition affecting 10-12% of the general population and is one of the leading causes for referral to secondary care. Many conditions have been associated with chronic cough, including asthma, gastro-esophageal reflux disease and upper airways cough syndrome. Inflammatory airway conditions including cough variant asthma (CVA) and non-asthmatic eosinophilic bronchitis (NAEB) contribute to a significant proportion of presentations with chronic cough, with differing diagnostic criteria and different responses to commonly used asthma therapy for their respective diagnoses. Mechanistic studies in both animal models and humans have identified increased neuronal sensitivity and subsequent central sensitization. These mechanisms include inflammatory-mediated nociceptor sensitization and alterations of afferent nerve terminal excitability, phenotypic changes in the vagal afferent neurons over time, and central neuroplasticity resulting from increased synaptic signalling from peripheral afferents. The aim of this review is to discuss the mechanisms, neurophysiology, and management approaches currently available for patients presenting with chronic cough with underlying asthma, CVA, and NAEB and to shed a light on areas of further research required to elucidate the mechanisms of cough in this patient population.

Effects of treatment with montelukast alone, budesonide/formoterol alone and a combination of both in cough variant asthma

Background

Whether cysteinyl-leukotriene receptor antagonists (LTRAs) have a similar antitussive effect to inhaled corticosteroids and long-acting β2-agonist (ICS/LABA), and that LTRA plus ICS/LABA is superior to LTRAs alone or ICS/LABA alone in treating cough variant asthma (CVA) remain unclear. This study aimed to investigate and compare the efficacy of montelukast alone, budesonide/formoterol alone and the combination of both in the treatment of CVA.

Methods

Ninety-nine CVA patients were assigned randomly in a 1:1:1 ratio to receive montelukast (M group: 10 mg, once daily), budesonide/formoterol (BF group: 160/4.5 μg, one puff, twice daily), or montelukast plus budesonide/formoterol (MBF group) for 8 weeks. The primary outcomes were changes in the cough visual analogue scale (VAS) score, daytime cough symptom score (CSS) and night-time CSS, and the secondary outcomes comprised changes in cough reflex sensitivity (CRS), the percentage of sputum eosinophils (sputum Eos%) and fractional exhaled nitric oxide (FeNO). CRS was presented with the lowest concentration of capsaicin that induced at least 5 coughs (C5). The repeated measure was used in data analysis.

Results

The median cough VAS score (median from 6.0 to 2.0 in the M group, 5.0 to 1.0 in the BF group and 6.0 to 1.0 in the MBF group, all p < 0.001), daytime CSS (all p < 0.01) and night-time CSS (all p < 0.001) decreased significantly in all three groups after treatment for 8 weeks. Meanwhile, the LogC5 and sputum Eos% improved significantly in all three groups after 8 weeks treatment (all p < 0.05). No significant differences were found in the changes of the VAS score, daytime and night-time CSSs, LogC5 and sputum Eos% among the three groups from baseline to week 8 (all p > 0.05). The BF and MBF groups also showed significant decreases in FeNO after 8 weeks treatment (p = 0.001 and p = 0.008, respectively), while no significant change was found in the M group (p = 0.457). Treatment with MBF for 8 weeks significantly improved the FEV₁/FVC as well as the MMEF% pred and decreased the blood Eos% (all p < 0.05).

Conclusions

Montelukast alone, budesonide/formoterol alone and a combination of both were effective in improving cough symptom, decreasing cough reflex sensitivity and alleviating eosinophilic airway inflammation in patients with CVA, and the antitussive effect and anti-eosinophilic airway inflammation were similar.

Trial registration ClinicalTrials.gov, number NCT01404013.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02114-6.

Objective and Subjective Measurement of Cough in Asthma: A Systematic Review of the Literature

Background

The extent to which objective and subjective tools has been used to measure the characteristics and burden of cough in patients with asthma has not been reported.

Objective

To review the large and extensive body of literature in asthma with the specific hypothesis that the characteristics of cough and clinical impact in this disease has only occasionally been studied.

Methods

For this systematic review, we searched EMBASE and MEDLINE databases using a combination of MeSH terms for “cough” and “asthma” for studies published up to and including end of August 2021. Studies included for analysis were confined to those undertaken in adult patients (≥ 18 years) with asthma of any severity where any tool or method to specifically measure cough was employed.

Results

Of 12,090 citations identified after our initial search, 112 full-text articles met criteria for inclusion in our analysis. We found that a broad range of objective and subjective measures have been used albeit with a lack of consistency between studies. Clinically important levels of cough associated with impaired health status were identified in patients with asthma.

Conclusion

Although cough is a common symptom in asthma, the clinical features and accompanying healthcare burden have been studied infrequently. In studies where cough was measured, the methods employed varied considerably. A more consistent use of cough-specific measurement tools is required to better determine the nature and burden of cough in asthma.

Managing Chronic Cough Due to Asthma and NAEB in Adults and Adolescents: CHEST Guideline and Expert Panel Report

BACKGROUND

Asthma and non-asthmatic eosinophilic bronchitis (NAEB) are among the commonest causes of chronic cough in adults. We sought to determine the role of non-invasive measurements of airway inflammation, including induced sputum and fractional exhaled nitric oxide, in the evaluation of cough associated with asthma, and what the best treatment is for cough due to asthma or NAEB.

METHODS

We undertook three systematic reviews of randomized controlled trials and observational trials of adults and adolescents > 12 years of age with a chronic cough due to asthma or NAEB. Eligible studies were identified in MEDLINE, CENTRAL, and SCOPUS and assessed for relevance and quality. Guidelines were developed and voted upon using CHEST guideline methodology.

RESULTS

Of the citations reviewed, 3/1,175, 53/656, and 6/134 were identified as being eligible for inclusion in the three systematic reviews, respectively. In contrast to established guidelines for asthma therapies in general and the inclusion in some guidelines for a role of biomarkers of airway inflammation to guide treatment in severe disease, the evidence of specific benefit related to the use of non-invasive biomarkers in patients with chronic cough due to asthma was weak. The best therapeutic option for cough in asthma or NAEB is inhaled corticosteroids followed by leukotriene receptor antagonism.

CONCLUSIONS

This guideline offers recommendations on the role of non-invasive measurements of airway inflammation and treatment for cough due to asthma or NAEB based on the available literature, and identifies gaps in knowledge and areas for future research.

Screening Bioactive Compounds of Siraitia grosvenorii by Immobilized β2-Adrenergic Receptor Chromatography and Druggability Evaluation

As the first and key step of traditional Chinese medicine (TCM)-guided drug development, lead discovery necessitates continuous exploration of new methodology for screening bioactive compounds from TCM. This work intends to establish a strategy for rapidly recognizing β2-adrenergic receptor (β2-AR) target compounds from the fruit of Siraitia grosvenorii (LHG). The method involved immobilization of β2-AR onto amino-microsphere to synthesize the receptor column, the combination of the column to high-performance liquid chromatography (HPLC) to screen bioactive compounds of LHG, the identification of the compounds by HPLC coupled with mass spectrometry (MS), and the evaluation of druggability through pharmacokinetic examination by HPLC-MS/MS. Mogroside V was screened and identified as the β2-AR-targeted bioactive compounds in LHG. This compound exhibited desired pharmacokinetic behavior including the time to reach peak plasma concentrations of 45 min, the relatively low elimination of 138.5 min, and the high bioavailability. These parameters indicated that mogroside V has a good druggability for the development of new drugs fighting β2-AR-mediated respiratory ailments like asthma. The combination of the methods in this work is probably becoming a powerful strategy for screening and early evaluating the bioactive compounds specifically binding to G-protein-coupled receptor target from complex matrices including TCM.

Montelukast and budesonide combination for children with chronic cough-variant asthma

This study investigated the effectiveness and safety of montelukast combined budesonide (MCB) treatment for children with chronic cough-variant asthma (CCVA).In total, 82 cases of children with CCVA, aged 4 to 11 years were included in this study. All cases received either MCB or budesonide alone between May 2015 and April 2017. The primary outcome was lung function, measured by the peak expiratory flow rates (PEFRs) and forced expiratory volume in 1 second (FEV1). The secondary outcome was measured by the clinical assessment score. Furthermore, adverse events (AEs) were also recorded in this study. All outcomes were measured after 8-week treatment.After 8-week treatment, MCB showed greater effectiveness than did budesonide alone in improving the lung function, measured by PEFR V1 (P = .02), and FEV1 (P < .01). Similarly, the clinical assessment score also demonstrated significant difference between the 2 groups (P < .05). In addition, no serious AEs occurred in both groups.The results of this study demonstrate that the effectiveness of MCB is superior to budesonide alone in the treatment of children with CCVA.

Olodaterol attenuates citric acid-induced cough in naïve and ovalbumin-sensitized and challenged guinea pigs

Excessive coughing is a common feature of airway diseases. Different G-protein coupled receptors, including β2-adrenergic receptors (β2-AR), have been implicated in the molecular mechanisms underlying the cough reflex. However, the potential antitussive property of β2-AR agonists in patients with respiratory disease is a matter of ongoing debate. The aim of our study was to test the efficacy of the long-acting β2-AR agonist olodaterol with regard to its antitussive property in a pre-clinical model of citric acid-induced cough in guinea pigs and to compare the results to different clinically relevant β2-AR agonists. In our study β2-AR agonists were intratracheally administered, as dry powder, into the lungs of naïve or ovalbumin-sensitized guinea pigs 15 minutes prior to induction of cough by exposure to citric acid. Cough events were counted over 15 minutes during the citric acid exposure. Olodaterol dose-dependently inhibited the number of cough events in naïve and even more potently and with a greater maximal efficacy in ovalbumin-sensitized guinea pigs (p < 0.01). Formoterol and salmeterol showed a trend towards reducing cough. On the contrary, indacaterol demonstrated pro-tussive properties as it significantly increased the number of coughs, both in naïve and ovalbumin-sensitized animals (p < 0.001). In conclusion, olodaterol, at doses eliciting bronchodilation, showed antitussive properties in a model of citric acid-induced cough in naïve and ovalbumin-sensitized guinea pigs. This is in agreement with pre-clinical and clinical studies showing antitussive efficacy of β2-AR agonists. Indacaterol increased the number of coughs in this model, which concurs with clinical data where a transient cough has been observed after indacaterol inhalation. While the antitussive properties of β2-AR agonists can be explained by their ability to lead to the cAMP-induced hyperpolarization of the neuron membrane thereby inhibiting sensory nerve activation and the cough reflex, the mechanism underlying the pro-tussive property of indacaterol is not known.

Effects of regular treatment with combination of salmeterol/fluticasone propionate and salmeterol alone in cough variant asthma

OBJECTIVE

Cough variant asthma (CVA) is an important cause of chronic cough, and pathophysiological features of the disease appear to be similar to typical asthma. Because CVA is recognized as a precursor of asthma, early intervention with long-term anti-inflammatory agents may be recommended. However, the role of combination therapy with inhaled corticosteroid and β2-agonist in the treatment of CVA has not been elucidated. To evaluate the effectiveness of the combination therapy, we investigated the clinical impact of regular treatment with salmeterol/fliticasone propionate combination (SFC) and inhaled salmeterol (SAL) alone in patients with CVA.

METHODS

The study was a randomized, controlled, parallel-group multi-center trial. Forty-three CVA patients were assigned to SFC (50/100 µg once daily) or SAL (50 µg twice daily) for 12 weeks. Then, these medications were stopped for the next 24 weeks. Main outcome measures were cough symptoms, pulmonary function and airway inflammation.

RESULTS

Treatment with each of SFC and SAL significantly decreased cough scores and increased FEV1 and PEF, where the efficacy was more pronounced with SFC than SAL. SFC also decreased sputum eosinophil counts and eosinophil cationic protein contents, whereas SAL had no effect. After discontinuation of the treatment, cough scores increased, pulmonary function and eosinophilic airway inflammation were aggravated and returned to the baseline levels.

CONCLUSIONS

Maintenance therapy with SFC provides further improvements in cough symptoms, pulmonary function and airway inflammation, and discontinuation of the therapy causes worsening of the disease, indicating that stopping or interrupting anti-inflammatory therapy may not be advisable in patients with CVA.

Efficacy of procaterol combined with inhaled budesonide for treatment of cough-variant asthma

BACKGROUND AND OBJECTIVE

Procaterol, a selective, short-acting beta-2 adrenoceptor agonist, is effective in treating 'classical' asthma, but its efficacy for cough-variant asthma (CVA) is unknown. We evaluated the efficacy and safety of procaterol combined with budesonide for CVA.

METHODS

A prospective, randomized, double-blind, placebo-controlled, multicenter trial in China was conducted. One hundred and fifty-nine patients diagnosed with CVA (aged 18-75 years) were randomly divided into two groups to receive twice daily for 8 weeks, inhaled budesonide 100 μg plus either oral procaterol 25 μg or placebo. Primary and secondary efficacy variables were cough symptom severity scores and Leicester Cough Questionnaire (LCQ) life quality scores. Adverse events were also assessed.

RESULTS

The budesonide/placebo and budesonide/procaterol groups contained 80 and 78 participants (one excluded for later diagnosis of eosinophilic bronchitis), respectively, with similar baseline characteristics. Daily cough score declined during treatment in both groups and was lower in the budesonide/procaterol group at 8 (0.44 vs 0.73) and 10 (0.36 vs 0.69) weeks (P < 0.05). Compared with the budesonide/placebo group, the proportion of patients with a reduction of 3 points or greater (66% vs 42%) and that of patients scoring 0 points (63% vs 51%) was higher in the budesonide/procaterol group for daily cough scores (P < 0.05). At 8 weeks, LCQ score improvement was superior in the budesonide/procaterol group (38.94 ± 19.24 vs 32.71 ± 18.92; P < 0.05).

CONCLUSION

Procaterol combined with budesonide was well tolerated and effective at improving cough symptoms and quality of life in patients with CVA.

Antitussive drugs--past, present, and future

Cough remains a serious unmet clinical problem, both as a symptom of a range of other conditions such as asthma, chronic obstructive pulmonary disease, gastroesophageal reflux, and as a problem in its own right in patients with chronic cough of unknown origin. This article reviews our current understanding of the pathogenesis of cough and the hypertussive state characterizing a number of diseases as well as reviewing the evidence for the different classes of antitussive drug currently in clinical use. For completeness, the review also discusses a number of major drug classes often clinically used to treat cough but that are not generally classified as antitussive drugs. We also reviewed a number of drug classes in various stages of development as antitussive drugs. Perhaps surprising for drugs used to treat such a common symptom, there is a paucity of well-controlled clinical studies documenting evidence for the use of many of the drug classes in use today, particularly those available over the counter. Nonetheless, there has been a considerable increase in our understanding of the cough reflex over the last decade that has led to a number of promising new targets for antitussive drugs being identified and thus giving some hope of new drugs being available in the not too distant future for the treatment of this often debilitating symptom.

Leukotriene receptor antagonists pranlukast and montelukast for treating asthma

INTRODUCTION

The prevalence of bronchial asthma, which is a chronic inflammatory disorder of the airway, is increasing worldwide. Although inhaled corticosteroids (ICS) play a central role in the treatment of asthma, they cannot achieve good control for all asthmatics, and medications such as leukotriene receptor antagonists (LTRAs) with bronchodilatory and anti-inflammatory effects often serve as alternatives or add-on drugs.

AREAS COVERED

Clinical trials as well as basic studies of montelukast and pranlukast in animal models are ongoing. This review report clarifies the current status of these two LTRAs in the treatment of asthma and their future direction.

EXPERT OPINION

LTRAs could replace ICS as first-line medications for asthmatics who are refractory to ICS or cannot use inhalant devices. Further, LTRAs are recommended for asthmatics under specific circumstances that are closely associated with cysteinyl leukotrienes (cysLTs). Considering the low incidence of both severe adverse effects and the induction of tachyphylaxis, oral LTRAs should be more carefully considered for treating asthma in the clinical environment. Several issues such as predicted responses, effects of peripheral airway and airway remodeling and alternative administration routes remain to be clarified before LTRAs could serve a more effective role in the treatment of asthma.

Airway obstruction lability helps distinguish levels of disease activity in asthma

Classifying disease activity in asthma relies on clinical and physiological variables, but these variables do not capture all aspects of asthma that distinguish levels of disease activity. We used data from two pivotal trials of montelukast in asthma to classify disease activity as "high" or "low". We performed a principal component analysis (PCA) of disease activity using 21 efficacy outcome variables, including several novel derived outcome variables reflecting clinical and airway obstruction lability. Then we performed discriminant analysis (DA) based on disease activity classification. PCA revealed 6 factors (daytime asthma control, nighttime-predominant asthma control, airway obstruction, exacerbations, clinical lability, airway obstruction lability) that explained 76% of the variance between outcome variables. Although airway obstruction lability (comprising both diurnal variability in peak expiratory flow and diurnal variability in β-agonist use) accounted for only 6% of the explained variance in PCA, in DA it was more accurate (canonical coefficient 0.75) than traditional measures of asthma severity such as obstruction (-0.54) and daytime control (-0.56) in distinguishing between high and low disease activity. We conclude that airway obstruction lability, a parameter not typically captured in clinical trials, may contribute to more complete assessment of asthma disease activity and may define an emerging clinical target of future therapy.