Alternative mechanisms for tiotropium

Effective-compound combination of Bufei Yishen formula III combined with ER suppress airway mucus hypersecretion in COPD rats: via EGFR/MAPK signaling

BACKGROUND

The aim of this study was to explore the combined efficacy ofeffective-component compatibility of Bufei Yishen formula III (ECC-BYF III) and exercise rehabilitation (ER) in inhibiting airway mucus hypersecretion in a chronic obstructive pulmonary disease (COPD) rat model.

METHODS

A total of 48 SD rats were divided into control, model, acetylcysteine (NAC), ECC-BYF III, ER, and ECC-BYF III + ER groups (n=8). COPD rats were exposed to cigarette smoke and bacteria for 8 weeks and administered various treatments over the next eight weeks. Rats were euthanized at week 17 after pulmonary function testing. Pathological examination of lung tissues was performed. IL-6 and IL-10 levels were measured in bronchoalveolar lavage fluid (BALF) and protein levels of MUC5AC, MUC5B, AQP-5, EGFR, ERK, JNK, and p38 were measured in lung tissues.

RESULTS

Improved pulmonary function and pathological changes were observed in ECC-BYF III, ECC-BYF III + ER, and NAC groups. ECC-BYF III and ECC-BYF III + ER had greater mean alveolar number (MAN) compared with NAC. Lung inflammation and goblet cell generation were reduced and MUC5AC, MUC5B and AQP-5 expressions were lower in all treatment groups. ECC-BYF III has more significant effect on MUC5AC than ER and NAC. ECC-BYFIII + ER had a greater effect on suppressing IL-6 in BALF compared with other treatments. ECC-BYFIII, ER, and ECC-BYF III + ER reduced EGFR, ERK, JNK, and p38 phosphorylated protein levels. ECC-BYFIII+ER had a greater effect on p-JNK and p-p38 than ECC-BYFIII and NAC.

CONCLUSION

ECC-BYF III, ER, and ECC-BYF III + ER have efficacy in inhibiting airway mucus hypersecretion with improved pulmonary function and pathological changes. ECC-BYF III had a greater effect in improving MAN and MUC5AC in lung tissue. ECC-BYF III+ER had a greater effect in alleviating pulmonary pathology and inflammation. These effects may be mediated by inhibition of the EGFR/MAPK pathway.

Immunogenetics and pharmacogenetics of allergic asthma in Africa

Asthma is a common chronic condition in children and in an African setting is often highly prevalent in urban areas as compared to rural areas. Asthma is a heritable disease and the genetic risk is often exacerbated by unique localised environmental factors. The Global Initiative for Asthma (GINA) recommendation for the control of asthma includes inhaled corticosteroids (ICS) alone or together with short-acting β₂-agonists (SABA) or long-acting β₂-agonists (LABA). While these drugs can relieve asthma symptoms, there is evidence of reduced efficacy in people of African ancestry. Whether this is due to immunogenetics, genomic variability in drug metabolising genes (pharmacogenetics) or genetics of asthma-related traits is not well defined. Pharmacogenetic evidence of first-line asthma drugs in people of African ancestry is lacking and is further compounded by the lack of representative genetic association studies in the continent. In this review, we will discuss the paucity of data related to the pharmacogenetics of asthma drugs in people of African ancestry, mainly drawing from African American data. We will further discuss how this gap can be bridged to improve asthma health outcomes in Africa.

The 5T approach in asthma: Triple Therapy Targeting Treatable Traits

Using a therapeutic strategy that is free from traditional diagnostic labels and based on the identification of "treatable traits" (TTs), which are influential in clinical presentations in each patient, might overcome the difficulties in identifying and validating asthma phenotypes and endotypes. Growing evidence is documenting the importance of using the triple therapy with ICS, LABA, and LAMAs in a single inhaler (SITT) in cases of asthma not controlled by ICS/LABA and in the prevention of exacerbations. The identification of TTs may overcome the possibility of using SITT without considering the specific needs of the patient. In effect, it allows a treatment strategy that is closer to the precision strategy now widely advocated for the management of patients with asthma. There are different TTs in asthma that may benefit from treatment with SITT, regardless of guideline recommendations. The airflow limitation and small airway dysfunction are key TTs that are present in different phenotypes/endotypes, do not depend on the degree of T2 inflammation, and respond better than other treatments to SITT. We suggest that the 5T (Triple Therapy Targeting Treatable Traits) approach should be applied to the full spectrum of asthma, not just severe asthma, and, consequently, SITT should begin earlier than currently recommended.

Tiotropium treatment for bronchiectasis: a randomised, placebo-controlled, crossover trial

Tiotropium via HandiHaler® is an established long-acting, anticholinergic bronchodilator that prevents exacerbations and improves lung function in patients with COPD. We hypothesized that tiotropium would reduce pulmonary exacerbations and improve lung function in patients with stable bronchiectasis and airflow limitation, and assessed the effect of tiotropium on these outcomes. In a randomised, double-blind, 2-period crossover trial, we recruited adult patients from 3 hospitals in New Zealand. Patients were excluded if they had a smoking history of more than 20 pack years. Patients were assigned to either the tiotropium-placebo or placebo-tiotropium sequence in a 1:1 ratio, using randomly permuted blocks stratified by centre. Participants and investigators were masked to treatment allocation. Eligible patients received tiotropium 18mcg via the HandiHaler® device daily for 6 months followed by 6 months of placebo, or vice versa, with a washout period of 4 weeks. The primary endpoint was rate of event-based exacerbations during the 6-month period. Primary analyses were carried out in an intention-to-treat set. Ninety patients were randomly assigned and 85 completed both treatment cycles. The rate of exacerbations under the tiotropium treatment was 2.17 y^-1 and 2.27 y^-1 under placebo (rate ratio 0.96, 95% CI 0.72-1.27; p=0.77). Tiotropium, as compared with placebo, improved FEV₁ by 58 mL (95% CI 23-92; p=0.002). Adverse events were similar under both treatments. Tiotropium via HandiHaler® over 6 months significantly improved lung function but not frequency of exacerbations. Further research is required to understand the clinical context and significance of these findings.

Application of aerosol therapy in respiratory diseases in children: A Saudi expert consensus

The Saudi Pediatric Pulmonology Association (SPPA) is a subsidiary of the Saudi Thoracic Society (STS), which consists of a group of Saudi experts with well-respected academic and clinical backgrounds in the fields of asthma and other respiratory diseases. The SPPA Expert Panel realized the need to draw up a clear, simple to understand, and easy to use guidance regarding the application of different aerosol therapies in respiratory diseases in children, due to the high prevalence and high economic burden of these diseases in Saudi Arabia. This statement was developed based on the available literature, new evidence, and experts' practice to come up with such consensuses about the usage of different aerosol therapies for the management of respiratory diseases in children (asthma and nonasthma) in different patient settings, including outpatient, emergency room, intensive care unit, and inpatient settings. For this purpose, SPPA has initiated and formed a national committee which consists of experts from concerned specialties (pediatric pulmonology, pediatric emergency, clinical pharmacology, pediatric respiratory therapy, as well as pediatric and neonatal intensive care). These committee members are from different healthcare sectors in Saudi Arabia (Ministry of Health, Ministry of Defence, Ministry of Education, and private healthcare sector). In addition to that, this committee is representing different regions in Saudi Arabia (Eastern, Central, and Western region). The subject was divided into several topics which were then assigned to at least two experts. The authors searched the literature according to their own strategies without central literature review. To achieve consensus, draft reports and recommendations were reviewed and voted on by the whole panel.

Drug class effects on respiratory mechanics in animal models: access and applications

Assessment of respiratory mechanics extends from basic research and animal modeling to clinical applications in humans. However, to employ the applications in human models, it is desirable and sometimes mandatory to study non-human animals first. To acquire further precise and controlled signals and parameters, the animals studied must be further distant from their spontaneous ventilation. The majority of respiratory mechanics studies use positive pressure ventilation to model the respiratory system. In this scenario, a few drug categories become relevant: anesthetics, muscle blockers, bronchoconstrictors, and bronchodilators. Hence, the main objective of this study is to briefly review and discuss each drug category, and the impact of a drug on the assessment of respiratory mechanics. Before and during the positive pressure ventilation, the experimental animal must be appropriately sedated and anesthetized. The sedation will lower the pain and distress of the studied animal and the plane of anesthesia will prevent the pain. With those drugs, a more controlled procedure is carried out; further, because many anesthetics depress the respiratory system activity, a minimum interference of the animal's respiration efforts are achieved. The latter phenomenon is related to muscle blockers, which aim to minimize respiratory artifacts that may interfere with forced oscillation techniques. Generally, the respiratory mechanics are studied under appropriate anesthesia and muscle blockage. The application of bronchoconstrictors is prevalent in respiratory mechanics studies. To verify the differences among studied groups, it is often necessary to challenge the respiratory system, for example, by pharmacologically inducing bronchoconstriction. However, the selected bronchoconstrictor, doses, and administration can affect the evaluation of respiratory mechanics. Although not prevalent, studies have applied bronchodilators to return (airway resistance) to the basal state after bronchoconstriction. The drug categories can influence the mathematical modeling of the respiratory system, systemic conditions, and respiratory mechanics outcomes.

The Impact of Muscarinic Receptor Antagonists on Airway Inflammation: A Systematic Review

Long-acting muscarinic receptor antagonists (LAMAs) are the cornerstone for the treatment of chronic obstructive pulmonary disease (COPD); furthermore, tiotropium is approved as add-on therapy in severe asthmatic patients. Accumulating evidence suggests that LAMAs may modulate airway contractility and airway hyperresponsiveness not only by blocking muscarinic acetylcholine receptors (mAchRs) expressed on airway smooth muscle but also via anti-inflammatory mechanisms by blocking mAchRs expressed on inflammatory cells, submucosal glands, and epithelial cells. The aim of this systematic review, performed according to the PRISMA-P guidelines, was to provide a synthesis of the literature on the anti-inflammatory impact of muscarinic receptor antagonists in the airways. Most of the current evidence originates from studies on tiotropium, that demonstrated a reduction in synthesis and release of cytokines and chemokines, as well as the number of total and differential inflammatory cells, induced by different pro-inflammatory stimuli. Conversely, few data are currently available for aclidinium and glycopyrronium, whereas no studies on the potential anti-inflammatory effect of umeclidinium have been reported. Overall, a large body of evidence supports the beneficial impact of tiotropium against airway inflammation. Further well-designed randomized controlled trials are needed to better elucidate the anti-inflammatory mechanisms leading to the protective effect of LAMAs against exacerbations via identifying suitable biomarkers.

Tiotropium in asthma - perspectives for the primary care physician

Asthma is a heterogeneous disease characterized by airway inflammation resulting from complex interactions between multiple hosts as well as environmental factors. As a chronic respiratory condition, asthma exerts a significant impact on patients and the healthcare system. Per the Global Initiative for Asthma (GINA), inhaled corticosteroids (ICS) with/without long-acting beta₂-agonists (LABAs) should be used as the preferred controllers for the management of asthma. Despite a range of therapeutic options, many patients with asthma remain uncontrolled, resulting in an increased risk of hospitalization and emergency room visits and a worsened quality of life. Tiotropium (Spiriva®, Boehringer Ingelheim Pharmaceuticals, Inc; 1.25 µg, two puffs, once daily), delivered via the Respimat® inhaler (Boehringer Ingelheim Pharmaceuticals, Inc.), was the first long-acting muscarinic antagonist to be approved as an add-on maintenance treatment option for patients with asthma aged ≥6 years at GINA steps 4 and 5. By binding to the muscarinic receptors M1 and M3 in the bronchial airways, tiotropium antagonizes the action of acetylcholine, leading to smooth muscle relaxation and reduced mucus secretion.The efficacy and safety of tiotropium add-on to ICS±LABA maintenance treatment have been evaluated in randomized controlled trials (RCTs) involving patients with a range of asthma severities (mild, moderate, and severe) and across age groups (children, adolescents, and adults). Add-on tiotropium was found to be well tolerated and efficacious in all RCTs. Moreover, the findings from real-world studies complement results from RCTs, showing beneficial effects of tiotropium in reducing exacerbations, hospitalization, emergency room visits, and asthma worsening.In this review article, we discuss the pathophysiology of asthma and the role of tiotropium in the management of asthma from the perspective of a primary care physician.

Anti-muscarinic drugs as preventive treatment of exercise-induced bronchoconstriction (EIB) in children and adults

Regular physical activity is strongly recommended to prevent chronic respiratory diseases, including asthma. On the other hand, vigorous physical training may trigger airway symptoms and bronchoconstriction. The transient airway narrowing occurring because of exercise is named exercise-induced bronchoconstriction (EIB). Despite management according to guidelines, a significant proportion of patients experiences uncontrolled EIB, which thus represents a relevant unmet medical need. In particular, although prevention and treatment of EIB are effectively based on the use of beta-2 bronchodilator drugs, high heterogeneity in individual responses has been reported. Furthermore, even though beta-2 adrenergic drugs remain the mainstay of EIB management, occurrence of tolerance and side effects, as well as doping concerns have been reported with their use. In regard to this, inhaled antimuscarinics could represent an alternative or additional effective and safe bronchodilator therapeutic option for achieving optimal EIB control and minimize adverse events. The present systematic review aims to collect and provide the most updated and evidence-based literature findings on the efficacy and safety of short- and long-acting inhaled anti-muscarinic drugs for the preventive treatment of EIB in both children and adults. Take-Home Message: Anti-muscarinic drugs are effective and safe in preventing EIB, despite response variability is reported. Further studies should focus on long-acting molecules, chronic administration and phenotype-driven effects.

The reality of LAMAs for adult asthmatic patients

INTRODUCTION

The use of tiotropium is approved for the treatment of asthma. There are several studies completed or currently ongoing with the long-acting muscarinic antagonists (LAMAs) umeclidinium and glycopyrronium as an add-on asthma treatment. Adding a second bronchodilator with a different mechanism of action for the treatment of uncontrolled asthma may be a suitable therapeutic approach, although several issues still under discussion.

AREAS COVERED

The reality of LAMA plus long-acting beta-agonists (LABA) treatment for adult asthma. A systematic search was conducted on March 2020, and included 6 electronic databases: EMBASE, MEDLINE, Scopus, The Cochrane Library, Web of Science and Google Scholar.

EXPERT OPINION

A growing body of evidence generated from several randomized clinical trials is supporting the use of LAMA in adulthood asthma always in association with inhaled corticosteroid (ICS). Currently, only tiotropium has been approved and included in the guidelines. Other LAMAs are under evaluation in clinical trials. Several clinical trials are supporting the use of a triple therapy (ICS/LABA/LAMA) in uncontrolled asthmatic patients under ICS/LABA.

New perspectives on the role of muscarinic antagonists in asthma therapy

INTRODUCTION

There is increasing evidence that tiotropium, a long-acting muscarinic agent (LAMA), is useful in the presence of severe-uncontrolled asthma despite the optimization of therapy with inhaled corticosteroids (ICSs) and long-acting β₂ agonists (LABAs) as recommended by the current guidelines. Furthermore, in recent years there have been several  preclinical and clinical studies on the pharmacological and therapeutic impact of other LAMAs in asthma.

AREAS COVERED

We have conducted an extensive search on muscarinic antagonists in asthma therapy throughout several sources and discuss what has emerged in the last 3 years (January 2017-March 2020).

EXPERT OPINION

New evidence indicates that the effectiveness of adding a LAMA, at least tiotropium, is independent of the degree of the type 2 inflammation and age of patient. Therefore, tiotropium can be administered without the need for patient phenotyping. Umeclidinium and glycopyrronium also appear effective in asthma. Initial treatment with LAMA+ICS for those with mild asthma may be an equally effective therapeutic option as LABA+ICS but this hypothesis should be confirmed by statistically powered trials.

Effect of Tiotropium Bromide on Airway Inflammation and Programmed Cell Death 5 in a Mouse Model of Ovalbumin-Induced Allergic Asthma

Rationale

We previously demonstrated increased expression of programmed cell death 5 (PDCD5) in asthmatic patients and ovalbumin-induced allergic asthma. International guidelines (GINA 2019) have included the use of tiotropium bromide for chronic treatment of the most severe and frequently exacerbated asthma in patients ≥6 years old, who do not have good response to inhaled corticosteroids.

Objective

To explore the role of tiotropium and its effect on PDCD5 level in a mouse model of chronic asthma.

Methods

We divided 12 female mice into 2 groups: untreated asthma (n = 6) and tiotropium-treated asthma (n = 6). The impact of tiotropium was assessed by histology of lung tissue and morphometry. Pulmonary function was tested by using pressure sensors. The number of cells in bronchoalveolar lavage fluid (BALF) was detected. Levels of PDCD5, active caspase-3, and muscarinic acetylcholine receptors M2 (ChRM2) and M3 (ChRM3) were examined.

Results

Tiotropium treatment significantly reduced airway inflammation and remodeling in asthmatic mice and intensified the lung function. PDCD5 level was reduced with tiotropium (p < 0.05). Moreover, active caspase-3 level was decreased with tiotropium (p < 0.001), and ChRM3 level was increased.

Conclusions

Tiotropium treatment may alleviate the pathological changes with asthma by regulating apoptosis.

The Airways' Mechanical Stress in Lung Disease: Implications for COPD Pathophysiology and Treatment Evaluation

The airway epithelium stretches and relaxes during the normal respiratory cycle, and hyperventilation exaggerates this effect, resulting in changes in lung physiology. In fact, stretching of the airways influences lung function and the secretion of airway mediators, which in turn may cause a potentially injurious inflammatory response. This aim of the present narrative review was to illustrate the current evidence on the importance of mechanical stress in the pathophysiology of lung diseases with a particular focus on chronic obstructive pulmonary disease (COPD) and to discuss how this may influence pharmacological treatment strategies. Overall, treatment selection should be tailored to counterpart the effects of mechanical stress, which influences inflammation both in asthma and COPD. The most suitable treatment approach between a long-acting β2-agonists/long-acting antimuscarinic-agonist (LABA/LAMA) alone or with the addition of inhaled corticosteroids should be determined based on the underlying mechanism of inflammation. Noteworthy, the anti-inflammatory effects of the glycopyrronium/indacaterol combination on hyperinflation and mucociliary clearance may decrease the rate of COPD exacerbations, and it may synergistically improve bronchodilation with a double action on both the cyclic adenosine monophosphate (cAMP) and the acetylcholine pathways.

Tiotropium inhibits proinflammatory microparticle generation by human bronchial and endothelial cells

Tiotropium is a muscarinic antagonist that reduces the risk of acute exacerbations of chronic obstructive pulmonary disease, possibly through an as yet incompletely characterized anti-inflammatory activity. We hypothesized that muscarinic activation of bronchial epithelial cells and endothelial cells causes the release of proinflammatory microparticles and that tiotropium inhibits the phenomenon. Microparticle generation was assessed by a functional assay, by flow cytometry and by NanoSight technology. Immortalized bronchial epithelial cells (16HBE) and umbilical vein endothelial cells were treated with acetylcholine in the presence of varying concentrations of tiotropium. Intracellular calcium concentration, extracellular regulated kinase phosphorylation and chemokine content in the conditioned media were assessed by commercial kits. Acetylcholine causes microparticle generation that is completely inhibited by tiotropium (50 pM). Microparticles generated by acetylcholine-stimulated cells increase the synthesis of proinflammatory mediators in an autocrine fashion. Acetylcholine-induced upregulation of microparticle generation is inhibited by an inhibitor of extracellular regulated kinase phosphorylation and by a phospholipase C inhibitor. Tiotropium blocks both extracellular regulated kinase phosphorylation and calcium mobilization, consistent with the hypothesis that the drug prevents microparticle generation through inhibition of these critical pathways. These results might contribute to explain the effect of tiotropium in reducing acute exacerbations of chronic obstructive pulmonary disease.

IL-17A-associated IKK-α signaling induced TSLP production in epithelial cells of COPD patients

Thymic stromal lymphopoietin (TSLP) is a cytokine expressed in the epithelium, involved in the pathogenesis of chronic disease. IL-17A regulates airway inflammation, oxidative stress, and reduction of steroid sensitivity in chronic obstructive pulmonary disease (COPD). TSLP and IL-17A were measured in induced sputum supernatants (ISs) from healthy controls (HC), healthy smokers (HS), and COPD patients by enzyme-linked immunosorbent assay. Human bronchial epithelial cell line (16HBE) and normal bronchial epithelial cells were stimulated with rhIL-17A or ISs from COPD patients to evaluate TSLP protein and mRNA expression. The effects of the depletion of IL-17A in ISs, an anticholinergic drug, and the silencing of inhibitor kappa kinase alpha (IKKα) on TSLP production were evaluated in 16HBE cells. Coimmunoprecipitation of acetyl-histone H3(Lys14)/IKKα was evaluated in 16HBE cells treated with rhIL-17A and in the presence of the drug. TSLP and IL-17A levels were higher in ISs from COPD patients and HS compared with HC. TSLP protein and mRNA increased in 16HBE cells and in normal bronchial epithelial cells stimulated with ISs from COPD patients compared with ISs from HC and untreated cells. IKKα silencing reduced TSLP production in 16HBE cells stimulated with rhIL-17A and ISs from COPD patients. RhIL-17A increased the IKKα/acetyl-histone H3 immunoprecipitation in 16HBE cells. The anticholinergic drug affects TSLP protein and mRNA levels in bronchial epithelial cells treated with rhIL-17A or with ISs from COPD patients, and IKKα mediated acetyl-histone H3(Lys14). IL-17A/IKKα signaling induced the mechanism of chromatin remodeling associated with acetyl-histone H3(Lys14) and TSLP production in bronchial epithelial cells. Anticholinergic drugs might target TSLP derived from epithelial cells during the treatment of COPD.

Efficacy and safety of tiotropium bromide combined with budesonide/formoterol in the treatment of moderate to severe chronic obstructive pulmonary disease

With the increase of environmental pollution, chronic obstructive pulmonary disease (COPD) has become a serious health threat. In the present study, the efficacy and safety of inhalation therapy of tiotropium bromide combined with budesonide/formoterol were assessed in 180 patients with moderate to severe COPD (clinical trial registry no. ChiCTR1800017584). Patients were treated by inhalation of budesonide/formoterol (control group) or inhalation of tiotropium bromide combined with budesonide/formoterol (intervention group). The results indicated that after the treatment, the forced expiratory volume in 1 sec, the modified Medical Research Council scale, the 6-min walking distance and the St. George's Respiratory Questionnaire scores for quality of life were significantly improved in the two groups, while the improvements in the intervention group were more significant (all P<0.05). There was no significant difference in body mass indices between the two groups during the course of the treatment (P=0.302). The difference in the risk of an acute exacerbation between the two groups was also not significant (P=0.238). The median time to the first acute exacerbation from the start of treatment in the intervention group (53 days; 25% quartile, 50 days; 75% quartile, 62 days) was significantly longer than that in the control group (37 days; 25% quartile, 23 days; 75% quartile, 39 days; P=0.042). The adverse reaction rates in the intervention and control groups were 14.4 and 10.0%, respectively, without any significant difference. In conclusion, inhalation treatment of tiotropium bromide combined with budesonide/formoterol significantly improves pulmonary function, exercise capacity and quality of life of patients with COPD compared with budesonide/formoterol inhalation alone, while the effect of reducing the acute attack risk requires further evaluation.

Tiotropium add-on to inhaled corticosteroids versus addition of long-acting β2-agonists for adults with asthma

Additional management options, and better use of current options, are needed to help support a large proportion of patients with asthma whose symptoms remain uncontrolled on inhaled corticosteroids (ICS). Here, we aim to review the safety and efficacy of adding tiotropium to ICS compared with adding a long-acting β₂-agonist (LABA) for adults whose asthma is not well controlled on ICS alone. Adding tiotropium to a background of ICS provides beneficial effects that are comparable with addition of a LABA in terms of lung function measures, exacerbations, asthma control and other endpoints. In addition, tiotropium and LABAs are both well tolerated. Some patients respond to either tiotropium or LABA treatment, but not both, suggesting that there are groups of patients that may respond better to one of these drugs. Currently, tiotropium is recommended as an add-on therapy in patients with severe asthma (Global Initiative for Asthma Steps 4 and 5) whose asthma is uncontrolled despite treatment with ICS/LABA. Tiotropium is also effective in patients with less severe disease and may benefit patients who experience adverse events from LABA treatment or where LABAs are ineffective. Tiotropium is therefore an important therapeutic option in asthma, not only as recommended as an add-on treatment with ICS/LABA, but also as an alternative to the addition of LABA to maintenance therapy with an ICS.

Methacholine induces extracellular matrix production by human airway smooth muscle cells through β-catenin signaling

Altered extracellular matrix (ECM) production by airway smooth muscle cells (ASMCs) is an important feature of airway remodeling. Muscarinic receptor agonists contribute to ECM production in vivo, but the mechanisms involved remain unclear. This study attempted to investigate the role of methacholine in promoting ECM production by human ASMCs (HASMCs) and the underlying mechanism. We found that methacholine induced the expression of collagen I protein and multiple ECM genes. β-catenin signaling was activated in this process upon GSK3β phosphorylation, leading to upregulation of total and active β-catenin. Silencing β-catenin by specific small interfering RNA (siRNA) or with the β-catenin inhibitor, PKF115-584, decreased collagen I expression. Conversely, overexpression of active β-catenin by adenoviruses carrying the S33Y-β-catenin mutant increased the methacholine-induced collagen I expression. Furthermore, methacholine induced TGF-β expression in HASMCs, while pan-TGF-β-neutralizing antibody only partially decreased collagen I expression. These findings suggest that methacholine induced ECM production through β-catenin signaling and partially through TGF-β.

Managing problematic severe asthma: beyond the guidelines

This review discusses issues related to managing problematic severe asthma in children and young people. A small minority of children have genuinely severe asthma symptoms which are difficult to control. Children with genuinely severe asthma need investigations and treatments beyond those described within conventional guidelines. However, the majority of children with poor symptom control despite high-intensity treatment achieve improvement in their asthma control once attention has been paid to the basics of asthma management. Basic asthma management requires optimisation of inhaler technique and treatment adherence, avoidance of environmental triggers and self-management education. It is also important that clinicians recognise risk factors that predispose patients to asthma exacerbations and potentially life-threatening attacks. These correctable issues need to be tackled in partnership with children and young people and their families. This requires a coordinated approach between professionals across healthcare settings. Establishing appropriate infrastructure for coordinated asthma care benefits not only those with problematic severe asthma, but also the wider asthma population as similar correctable issues exist for children with asthma of all severities. Investigation and management of genuine severe asthma requires specialist multidisciplinary expertise and a systematic approach to characterising patients' asthma phenotypes and delivering individualised care. While inhaled corticosteroids continue to play a leading role in asthma therapy, new treatments on the horizon might further support phenotype-specific therapy.

Tiotropium Attenuates Refractory Cough and Capsaicin Cough Reflex Sensitivity in Patients with Asthma

BACKGROUND

Asthmatic cough is often refractory to standard treatments such as inhaled corticosteroids (ICS) and long-acting β₂ agonists (LABA). Tiotropium may modulate cough reflex sensitivity of acute viral cough, but its efficacy in asthmatic cough remains unknown.

OBJECTIVE

To evaluate whether tiotropium improves cough and cough reflex sensitivity in patients with asthma refractory to ICS/LABA.

METHODS

Seventeen consecutive patients with asthma with chronic cough despite the use of ICS/LABA (13 women; 43.4 ± 19.0 years; average ICS dose, 651 ± 189 μg/d; fluticasone equivalent) were additionally treated with tiotropium (5 μg/d) for 4 to 8 weeks to examine its effects on pulmonary function and capsaicin cough reflex sensitivity (cough thresholds C2 and C5). Cough severity, cough-specific quality of life, and asthma control were also evaluated using cough visual analog scales (VASs), the Japanese version of Leicester Cough Questionnaire (J-LCQ), and Asthma Control Test (ACT), respectively. Patients with an improved cough VAS score of 15 mm or more were considered responders to tiotropium.

RESULTS

Tiotropium significantly improved cough VAS, J-LCQ, and ACT scores, but not FEV₁. Changes in cough VAS score correlated with those in C2 (r = -0.58; P = .03), C5 (r = -0.58; P = .03), and ACT scores (r = -0.62; P = .02), but not in FEV₁ in the overall patients. When analyses were confined to the 11 responders, tiotropium significantly improved capsaicin cough reflex sensitivity within the subgroup (C2: P = .01 and C5: P = .02) and versus the nonresponders (C2: P = .004 and C5: P = .02).

CONCLUSION

Tiotropium may alleviate asthmatic cough refractory to ICS/LABA by modulating cough reflex sensitivity but not through bronchodilation.

Tiotropium for the Treatment of Asthma: Patient Selection and Perspectives

Asthma is a chronic disease of airway inflammation with a large global burden. Despite established, guideline-based stepwise therapy, a significant proportion of patients remain symptomatic and poorly controlled. As such, there is a need for additional safe, effective, convenient, and cost-effective therapies that can be broadly applied across a range of asthma phenotypes. Tiotropium is a long-acting muscarinic antagonist (LAMA) that leads to bronchodilation by blocking endogenous acetylcholine receptors in the airways. Tiotropium has long been approved for the treatment of chronic obstructive pulmonary disease, and it has recently been recognized for its safety and efficacy in improving lung function and controlling asthma. Evidence from several Phase III trials in the adult and paediatric population has shown that tiotropium is well tolerated and significantly improves a range of endpoints as an add-on treatment to ICS therapy, regardless of baseline characteristics and clinical phenotypes. Consequently, regulatory authorities worldwide have recently licensed tiotropium as the only LAMA approved for the treatment of asthma. This review provides an overview of safety and efficacy data and discusses the use of tiotropium in patients across the range of asthma severities, ages, and phenotypes.

Tiotropium in asthma: back to the future of anticholinergic treatment

Asthma is among the most common chronic diseases worldwide; however, despite progresses in the understanding of the patho-physiological mechanisms and advances in the development of new therapeutic options and strategies, the disease remains uncontrolled in a not trivial proportion of subjects. Thus, the need of new molecules to treat the underlying biological and functional abnormalities and to control symptoms is strongly advocated by clinicians. In this scenario, the most recent GINA guidelines have included the use of tiotropium bromide in the most severe and uncontrolled forms of the disease, in addition to treatment with inhaled corticosteroid plus long acting beta adrenergic agents. Indeed, a large body of evidence has accumulated to support the use of tiotropium bromide in asthma. The current review paper provides a state of the art systematic revision of findings on the efficacy and safety of tiotropium in the adult and paediatric asthma population. To this aim, electronic searches were undertaken in the most common scientific databases from the date of inception to March 2017. Robust and high quality evidence showed that tiotropium is effective and safe in both adults and children/adolescents. Predictive markers of response have been also suggested, as well as cost–benefit analyses reported. The tiotropium bronchodilator effect seems to be not solely related to the reduction of the smooth muscle tone. However, the observations on anti-inflammatory properties or reduction in mucus production, despite highly interesting, have been only demonstrated in in vitro studies and animal models, therefore advocating for further specifically designed investigations.

Cellular and molecular mechanisms of asthma and COPD

Asthma and chronic obstructive pulmonary disease (COPD) both cause airway obstruction and are associated with chronic inflammation of the airways. However, the nature and sites of the inflammation differ between these diseases, resulting in different pathology, clinical manifestations and response to therapy. In this review, the inflammatory and cellular mechanisms of asthma and COPD are compared and the differences in inflammatory cells and profile of inflammatory mediators are highlighted. These differences account for the differences in clinical manifestations of asthma and COPD and their response to therapy. Although asthma and COPD are usually distinct, there are some patients who show an overlap of features, which may be explained by the coincidence of two common diseases or distinct phenotypes of each disease. It is important to better understand the underlying cellular and molecular mechanisms of asthma and COPD in order to develop new treatments in areas of unmet need, such as severe asthma, curative therapy for asthma and effective anti-inflammatory treatments for COPD.

The evidence on tiotropium bromide in asthma: from the rationale to the bedside

Severe and poorly controlled asthma still accounts for a great portion of the patients affected. Disease control and future risk management have been identified by international guidelines as the main goals in patients with asthma. The need for new treatment approaches has led to reconsider anticholinergic drugs as an option for asthma treatment. Tiotropium is the first anticholinergic drug that has been approved for children and adults with poorly controlled asthma and is currently considered as an option for steps 4 and 5 of the Global Initiative for Asthma. In large randomized clinical trials enrolling patients with moderate to severe asthma, add-on therapy with tiotropium has demonstrated to be efficacious in improving lung function, decreasing risk of exacerbation and slowing the worsening of disease; accordingly, tiotropium demonstrated to be non inferior compared to long acting beta-agonists in the maintenance treatment along with medium to high inhaled corticosteroids. In view of the numerous ancillary effects acting on inflammation, airway remodeling, mucus production and cough reflex, along with the good safety profile and the broad spectrum of efficacy demonstrated in different disease phenotypes, tiotropium can represent a beneficial alternative in the therapeutic management of poorly controlled asthma. The present extensive narrative review presents the pharmacological and pathophysiological basis that guided the rationale for the introduction of tiotropium in asthma treatment algorithm, with a particular focus on its conventional and unconventional effects; finally, data on tiotropium efficacy and safety. from recent randomized clinical trials performed in all age categories will be extensively discussed.

Long-term treatment in pediatric asthma: an update on chemical pharmacotherapy

INTRODUCTION

Asthma is the most common chronic disease in childhood, affecting approximately 10% of all children, and is the leading cause of hospitalization in developed countries. In this paper we aimed to review the evidence on chemical pharmacotherapy for long-term treatment of pediatric asthma, according to the latest updates. Area covered: Long-term treatment, essential for controlling symptoms and reducing future risks including exacerbations and decline in lung function, includes control agents such as inhaled corticosteroids, long-acting beta2-adrenergic agonists, and leukotriene modifiers. More recent strategies based on the use of a biological drug such as omalizumab, which is a monoclonal antibody directed against immunoglobulin E (IgE), can be considered in selected patients with severe asthma. Expert opinion: In the near future, the challenge of childhood asthma treatment will be to improve the chemical drugs that already exist as well as to carefully characterize the several different asthma subtypes, with special regard to children with severe disease. A better definition of patient features, made possible by the current advanced knowledge of the pathobiology of severe asthma, can ultimately allow the identification of specific phenotypes and endotypes of severe asthma, aimed to personalize pharmacological treatment.

Why choose tiotropium for my patient? A comprehensive review of actions and outcomes versus other bronchodilators

PURPOSE

Chronic obstructive pulmonary disease (COPD) and asthma are leading causes of morbidity and mortality. This narrative review provides an appraisal of the pharmacological and clinical characteristics of tiotropium in COPD and asthma, and examines how these compare with other long-acting bronchodilators. The evidence base is placed into context by relating it to factors affecting clinicians' choice of therapy.

MAIN FINDINGS

Desirable attributes of a long-acting muscarinic antagonist (LAMA) maintenance therapy include effective pharmacological bronchodilation, improved lung function, exacerbation efficacy, and positive effects on symptom control, exercise capacity and quality of life across a broad patient population. Tolerability and convenience of use are also important for patient well-being and treatment adherence. Tiotropium shows higher affinity for muscarinic receptors than ipratropium, and prolonged binding to the M₃ receptor compared with other LAMAs. In COPD, tiotropium has demonstrated improved lung function and exacerbation prevention compared with placebo or long-acting β₂-agonists, similar exacerbation efficacy to other LAMAs, and enhanced symptom control and health status versus placebo. UniTinA-asthma^® showed the benefits of add-on tiotropium in patients with uncontrolled mild to moderate and severe asthma. Tiotropium is well tolerated, with an incidence of adverse events similar to placebo, except for known infrequent side effects of anticholinergics. Tiotropium HandiHaler^® and Respimat^® augment inhaler choice in COPD.

PRINCIPAL CONCLUSIONS

With over 10 years' prescribing history and 50 million patient-years of use, tiotropium has the benefit of a more extensive clinical evidence base than other long-acting bronchodilators, with demonstrated efficacy and safety in COPD and symptomatic asthma.

Role of muscarinic antagonists in asthma therapy

INTRODUCTION

Higher parasympathetic tone has been reported in asthmatics. In general, cholinergic contractile tone is increased by airway inflammation associated with asthma. Nevertheless, the role of muscarinic antagonists for the treatment of asthma has not yet been clearly defined. Areas covered: The use of SAMAs and LAMAs in asthma has been examined and discussed according with the published evidence. Particular attention has been given to the large Phase III clinical trial program designed to evaluate the efficacy and safety of tiotropium respimat added to standard treatment in adults, adolescents and children with persistent asthma across the spectrum of asthma severity. Expert commentary: The current evidence is that in patients with poorly controlled severe asthma despite the use of ICS and LABA, the addition of tiotropium significantly increases the time to the first severe exacerbation and provides a modest but sustained bronchodilation. Identical results should be produced using other LAMAs. In any case, the documentation that, at least in animal or in vitro models, LAMAs show significant anti-inflammatory and anti-proliferative capacities and are able to inhibit airway remodeling induced by allergens makes a strong presumption that the use of LAMAs in asthma may go beyond the simple bronchodilator effect.

Positioning of Long-Acting Muscarinic Antagonists in the Management of Asthma

Despite a range of efficacious therapies for asthma, including inhaled corticosteroids (ICS) and long-acting β₂-agonists (LABA), a significant proportion of patients have poor asthma control and retain a risk of future worsening of their symptoms. Long-acting muscarinic antagonist (LAMA) bronchodilators offer a well-tolerated, efficacious, and cost-effective add-on to a patient's treatment. Of the LAMAs currently under investigation or available for the treatment of asthma, evidence from a comprehensive clinical trial program in adults and children shows that once-daily treatment with tiotropium provides benefits for patients with uncontrolled asthma despite the use of ICS and LABAs. Tiotropium is included in the Global Initiative for Asthma (GINA) strategy document as an add-on therapy option for patients at Step 4 or 5 with a history of asthma exacerbations. Tiotropium Respimat® has demonstrated safety and efficacy in patients with a range of disease severities, ages, and phenotypes. This review describes the evidence for the use of LAMA as add-on therapy for patients with asthma who remain uncontrolled despite the use of ICS and LABA treatments.

Long-acting muscarinic antagonists: a potential add-on therapy in the treatment of asthma?

Asthma is a chronic inflammatory disorder of the airways that is a major global burden on both individuals and healthcare systems. Despite guideline-directed treatment, a significant proportion of patients with asthma do not achieve control. This review focuses on the potential use of long-acting anticholinergics as bronchodilators in the treatment of asthma, with results published from clinical trials of glycopyrrolate, umeclidinium and tiotropium. The tiotropium clinical trial programme is the most advanced, with data available from a number of phase II and III studies of tiotropium as an add-on to inhaled corticosteroid maintenance therapy, with or without a long-acting β2-agonist, in patients across asthma severities. Recent studies using the Respimat Soft Mist inhaler have identified 5 µg once daily as the preferred dosing regimen, which has shown promising results in adults, adolescents and children with asthma. Tiotropium Respimat has recently been incorporated into the Global Initiative for Asthma 2015 treatment strategy as a recommended alternative therapy at steps 4 and 5 in adult patients with a history of exacerbations. The increasing availability of evidence from ongoing and future clinical trials will be beneficial in determining where long-acting anticholinergic agents fit in future treatment guidelines across a variety of patient populations and disease severities.

Inhaled Umeclidinium in COPD Patients: A Review and Meta-Analysis

A number of new agents for the management of chronic obstructive pulmonary disease (COPD) are at different stages of development, including several inhaled long-acting antimuscarinics (LAMA). Long-acting bronchodilators are considered to be central to the management of COPD due to the evidence supporting their efficacy and safety. Umeclidinium, a LAMA, has recently been approved for the maintenance treatment of moderate to very severe COPD in a number of countries. This comprehensive review and pooled meta-analysis provides detailed information about the efficacy and safety of this agent. The pharmacokinetics and pharmacodynamics of umeclidinium observed in phase I and II studies support its once-daily administration. Umeclidinium is rapidly cleared from blood, and renal or hepatic impairment do not lead to significant changes in drug disposition. A pooled analysis of phase III and comparative studies of umeclidinium in patients with moderate to very severe COPD showed significant improvement in lung function measures, including trough forced expiratory volume in 1 s (FEV1), as well as in acute exacerbations of COPD, dyspnea, and quality of life. Adverse effects, including known anticholinergic effects, were uncommon with umeclidinium. Limited data suggest the efficacy of umeclidinium is similar to that of tiotropium. Umeclidinium is administered as a dry powder inhaler, provides adequate lung delivery in patients with moderate to very severe airflow obstruction, and appears to be easily used by patients. Umeclidinium provides a safe and effective option as an inhaled LAMA for the management of COPD.

Step 4: stick or twist? A review of asthma therapy

Many people with asthma do not achieve disease control, despite bronchodilators and inhaled corticosteroid therapy. People with uncontrolled asthma are at higher risk of an asthma attack and death, with mortality rates estimated at 1000 deaths/year in England and Wales. The recent National Review of Asthma Deaths (NRAD) report, ‘Why asthma still kills’, recommended that patients at step 4 or 5 of the British Thoracic Society/Scottish Intercollegiate Guidelines Network (BTS/SIGN) guidance must be referred to a specialist asthma service. This article reviews the 2014 evidence base for therapy of asthma patients at BTS/SIGN step 4 of the treatment cascade, in response to key findings of the NRAD report and lack of preferred treatment option at this step.

Tiotropium Attenuates Virus-Induced Pulmonary Inflammation in Cigarette Smoke-Exposed Mice

Viral infections trigger exacerbations in chronic obstructive pulmonary disease (COPD), and tiotropium, a M3 receptor antagonist, reduces exacerbations in patients by unknown mechanisms. In this report, we investigated whether tiotropium has anti-inflammatory effects in mice exposed to cigarette smoke (CS) and infected with influenza virus A/PR/8/34 (H1N1) or respiratory syncytial virus (RSV) and compared these effects with those of steroid fluticasone and PDE4-inhibitor roflumilast. Mice were exposed to CS; infected with H1N1 or RSV; and treated with tiotropium, fluticasone, or roflumilast. The amount of cells and cytokine levels in the airways, lung function, and viral load was determined. NCI-H292 cells were infected with H1N1 or RSV and treated with the drugs. In CS/H1N1-exposed mice, tiotropium reduced neutrophil and macrophage numbers and levels of interleukin-6 (IL-6) and interferon-γ (IFN-γ) in the airways and improved lung function. In contrast, fluticasone increased the loss of body weight; failed to reduce neutrophil or macrophage numbers; increased IL-6, KC, and tumor necrosis factor-α (TNF-α) in the lungs; and worsened lung function. Treatment with roflumilast reduced macrophage numbers, IL-6, and KC in the lungs but had no effect on neutrophil numbers or lung function. In CS/RSV-exposed mice, treatment with tiotropium, but not fluticasone or roflumilast, reduced neutrophil numbers and IL-6 and TNF-α levels in the lungs. Viral load of H1N1 and RSV was significantly elevated in CS/virus-exposed mice and NCI-H292 cells after fluticasone treatment, whereas tiotropium and roflumilast had no effect. In conclusion, tiotropium has anti-inflammatory effects on CS/virus-induced inflammation in mice that are superior to the effects of roflumilast and fluticasone. This finding might help to explain the observed reduction of exacerbation rates in COPD patients.

Therapeutic approaches to asthma-chronic obstructive pulmonary disease overlap syndromes

The recognition that there are some patients with features of asthma and chronic obstructive pulmonary disease (COPD) has highlighted the need to develop more specific treatments for these clinical phenotypes. Some patients with COPD have predominantly eosinophilic inflammation and might respond to high doses of inhaled corticosteroids and newly developed specific antieosinophil therapies, including blocking antibodies against IL-5, IL-13, IL-33, and thymic stromal lymphopoietin, as well as oral chemoattractant receptor-homologous molecule expressed on TH2 cells antagonists. Other patients have severe asthma or are asthmatic patients who smoke with features of COPD-induced inflammation and might benefit from treatments targeting neutrophils, including macrolides, CXCR2 antagonists, phosphodiesterase 4 inhibitors, p38 mitogen-activating protein kinase inhibitors, and antibodies against IL-1 and IL-17. Other patients appear to have largely fixed obstruction with little inflammation and might respond to long-acting bronchodilators, including long-acting muscarinic antagonists, to reduce hyperinflation. Highly selected patients with severe asthma might benefit from bronchial thermoplasty. Some patients with overlap syndromes can be conveniently treated with triple fixed-dose combination inhaler therapy with an inhaled corticosteroid, long-acting β2-agonist, and long-acting muscarinic antagonist, several of which are now in development. Corticosteroid resistance is a feature of asthma-COPD overlap syndrome, and understanding the various molecular mechanisms of this resistance has identified novel therapeutic targets and presented the prospect of therapies that can restore corticosteroid responsiveness.

Tiotropium Bromide in Chronic Obstructive Pulmonary Disease and Bronchial Asthma

Inhaled bronchodilators are the mainstay of pharmacological treatment for stable chronic obstructive pulmonary disease (COPD), including β2-agonists and muscarinic antagonists. Tiotropium bromide, a long-acting antimuscarinic bronchodilator (LAMA), is a treatment choice for moderate-to-severe COPD; its efficacy and safety have been demonstrated in recent trials. Studies also point to a beneficial role of tiotropium in the treatment of difficult-to-control asthma and a potential function in the asthma-COPD overlap syndrome (ACOS). Combination of different bronchodilator molecules and addition of inhaled corticosteroids are viable therapeutic alternatives. A condensation of the latest trials and the rationale behind these therapies will be presented in this article.

Pharmacologic rationale underlying the therapeutic effects of tiotropium/olodaterol in COPD

Bronchodilators are the most important drugs used for the treatment of chronic obstructive pulmonary disease (COPD). In particular, these therapeutic agents are mostly long-acting compounds utilized via inhalation, and include LAMA (long-acting muscarinic receptor antagonists) and LABA (long-acting β₂-adrenoceptor agonists). Because LAMA and LABA induce bronchodilation by distinct mechanisms of action, LABA/LAMA combinations provide a reciprocal potentiation of the pharmacological effects caused by each component. Hence, many COPD patients who do not achieve a satisfactory control of their symptoms using a single, either LAMA or LABA bronchodilator, can experience relevant benefits with the use of LAMA/LABA fixed combinations. Many different LAMA/LABA combinations have been recently developed and evaluated in randomized clinical trials. In this context, our review focuses on the pharmacological mechanisms underpinning the bronchodilation elicited by the LAMA tiotropium bromide and the LABA olodaterol. We also discuss the results of the most important clinical studies carried out in COPD patients to assess the efficacy and safety of tiotropium/olodaterol combinations.

Tiotropium attenuates IL-13-induced goblet cell metaplasia of human airway epithelial cells

BACKGROUND

It has been shown that acetylcholine is both a neurotransmitter and acts as a local mediator, produced by airway cells including epithelial cells. In vivo studies have demonstrated an indirect role for acetylcholine in epithelial cell differentiation. Here, we aimed to investigate direct effects of endogenous non-neuronal acetylcholine on epithelial cell differentiation.

METHODS

Human airway epithelial cells from healthy donors were cultured at an air-liquid interface (ALI). Cells were exposed to the muscarinic antagonist tiotropium (10 nM), interleukin (IL)-13 (1, 2 and 5 ng/mL), or a combination of IL-13 and tiotropium, during or after differentiation at the ALI.

RESULTS

Human airway epithelial cells expressed all components of the non-neuronal cholinergic system, suggesting acetylcholine production. Tiotropium had no effects on epithelial cell differentiation after air exposure. Differentiation into goblet cells was barely induced after air exposure. Therefore, IL-13 (1 ng/mL) was used to induce goblet cell metaplasia. IL-13 induced MUC5AC-positive cells (5-fold) and goblet cells (14-fold), as assessed by histochemistry, and MUC5AC gene expression (105-fold). These effects were partly prevented by tiotropium (47-92%). Goblet cell metaplasia was induced by IL-13 in a dose-dependent manner, which was inhibited by tiotropium. In addition, tiotropium reversed goblet cell metaplasia induced by 2 weeks of IL-13 exposure. IL-13 decreased forkhead box protein A2 (FoxA2) expression (1.6-fold) and increased FoxA3 (3.6-fold) and SAM-pointed domain-containing ETS transcription factor (SPDEF) (5.2-fold) expression. Tiotropium prevented the effects on FoxA2 and FoxA3, but not on SPDEF.

CONCLUSIONS

We demonstrate that tiotropium has no effects on epithelial cell differentiation after air exposure, but inhibits and reverses IL-13-induced goblet cell metaplasia, possibly via FoxA2 and FoxA3. This indicates that non-neuronal acetylcholine contributes to goblet cell differentiation by a direct effect on epithelial cells.

Acetylcholine beyond bronchoconstriction: roles in inflammation and remodeling

Acetylcholine is the primary parasympathetic neurotransmitter in the airways, where it not only induces bronchoconstriction and mucus secretion, but also regulates airway inflammation and remodeling. In this review, we propose that these effects are all primarily mediated via the muscarinic M3 receptor. Acetylcholine promotes inflammation and remodeling via direct effects on airway cells, and via mechanical stress applied to the airways sequential to bronchoconstriction. The effects on inflammation and remodeling are regulated by both neuronal and non-neuronal acetylcholine. Taken together, we believe that the combined effects of anticholinergic therapy on M3-mediated bronchoconstriction, mucus secretion, inflammation, and remodeling may account for the positive outcome of treatment with these drugs for patients with chronic pulmonary obstructive disease (COPD) or asthma.

Effect of viral upper respiratory tract infection on cough reflex sensitivity

Acute viral upper respiratory tract infection (URI; common cold) is among the most common medical conditions affecting man, with cough being a typical feature of the associated syndrome. Studies employing capsaicin inhalation challenge to measure cough reflex sensitivity have demonstrated a transient tussive hyperresponsiveness induced by URI that reverts to normal by 4-8 weeks post infection. Mechanisms proposed to explain the induction of cough by URI include a number of infection-associated airway effects, such as enhanced release of cytokines, neurotransmitters, and leukotrienes; increased neural receptor levels; reduced activity of neutral endopeptidases; transient modulation of afferent neural activity; mucus hypersecretion; and, possibly, effects on cholinergic motor pathways. Recent studies evaluating urge-to-cough (UTC), the sensation of irritation preceding the motor act of coughing, have demonstrated that URI induces a transient enhancement of UTC analogous to the effect observed on cough reflex sensitivity. The recently introduced concept of the Cough Hypersensitivity Syndrome may provide an explanation for the commonly observed clinical phenomenon of acute viral URI triggering what will develop into chronic, refractory cough in a subgroup of patients.

Tiotropium may improve asthma symptoms and lung function in asthmatic patients with irreversible airway obstruction: the real-life data

BACKGROUND AND AIMS

Some patients with asthma have poorly controlled disease despite the use of high-dose inhaled corticosteroids (ICS), long-acting β2 agonists (LABAs) and antileukotrienes. The aim of the study was to assess the effectiveness of tiotropium as an add-on therapy to the standard treatment with high-dose ICS/LABA on asthma control and lung function in patients with severe asthma.

METHODS

Of the 633 asthmatic patients, 64 (10.1%) patients with severe asthma who were add-on treated at least for 3 months were evaluated. Number of exacerbations, emergency department visits, hospitalizations and lung functions of patients belonging to 12 months before starting add-on treatment were compared with those of 12 months after starting add-on treatment.

RESULTS

The mean duration of add-on tiotropium treatment was 8.3 ± 0.5 months. For patients with severe asthma that was poorly controlled with standard combination therapy, tiotropium improved asthma control in 42.2%, decreased the number of emergency department visits in 46.9% and decreased the number of hospitalizations in 50.0% of them. The mean baseline forced expiratory volume in 1 s before add-on tiotropium was 57.5 ± 1.9% and forced vital capacity was 74.3 ± 15.6%. However, after 12 months of add-on tiotropium treatment, these rates became 65.5 ± 1.9% and 82.5 ± 15.1%, respectively. The addition of tiotropium significantly improved the percentages of the number of emergency department visits, the number of hospitalizations (P < 0.05).

CONCLUSION

Our study has suggested that, for patients with poorly controlled asthma despite of the use of ICS/LABA, the addition of tiotropium to standard care may be beneficial.

Effects of ipratropium on exercise-induced cough in winter athletes: a hypothesis-generating study

BACKGROUND

Exercise-induced cough (EIC) is frequently reported by winter athletes, but this symptom is not always associated with exercise-induced bronchoconstriction (EIB). The aims of this study were to determine if EIC can be inhibited or reduced with the inhalation of ipratropium, and if EIC in winter athletes is associated with EIB.

METHODS

On 2 visits, 24 cross-country skiers (10 males and 12 females, mean age 17 ± 3 years) performed an outdoor exercise in the winter (30-minute warm-up, followed by a 3-minute sprint), randomly preceded by the inhalation of ipratropium or a placebo. A spirometry was done at baseline and 20 minutes after inhalation of ipratropium or placebo. Exercise was then performed, followed by the measurement of forced expiratory volume in 1 second and the recording of the number of coughs until 60 minutes after exercise. Before and after exercise, the perception of cough intensity was evaluated using a modified Borg scale.

RESULTS

Twelve of 16 athletes who completed the study (75%) were symptomatic following exercise with placebo (number of coughs ≥ 5), but none developed EIB. For these athletes, the number of coughs after exercise (mean number of coughs ± standard deviation: placebo, 26 ± 14; ipratropium, 25 ± 23; P value, nonsignificant) and the maximal perception score for cough intensity (mean Borg score ± standard deviation: placebo, 1.9 ± 1.2; ipratropium, 2.0 ± 1.1; P value, nonsignificant) were not significantly different between ipratropium and placebo. A decrease in the number of coughs was observed in 6 of the symptomatic athletes and an increase was observed in the other 6, resulting in a nonsignificant mean effect.

CONCLUSIONS

Ipratropium does not appear to significantly influence the number and the perception of cough following exercise. Moreover, these results suggest that EIC is not mainly associated with EIB. However, a subgroup of athletes seems to show a beneficial response to ipratropium, suggesting different cough responses in this population.

Secretory hyperresponsiveness and pulmonary mucus hypersecretion

The term bronchial hyperresponsiveness is generally used to describe a heightened airway smooth muscle bronchoconstrictor response measured by bronchoprovocation testing. However, the airway also responds to inflammation or bronchoprovocation with increased mucus secretion. We use the term "secretory hyperresponsiveness" to mean increased mucus secretion either intrinsically or in response to bronchoprovocation. This is not the same as retained phlegm or sputum. Unlike smooth muscle contraction, which is rapidly reversible using a bronchodilator, mucus hypersecretion produces airflow limitation that reverses more slowly and depends upon secretion clearance from the airway. Certain groups of patients appear to have greater mucus secretory response, including those with middle lobe syndrome, cough-dominant ("cough-variant") asthma, and severe asthma. Secretory hyperresponsiveness also is a component of forms of lung cancer associated with bronchorrhea. An extreme form of secretory hyperresponsiveness may lead to plastic bronchitis, a disease characterized by rigid branching mucus casts that obstruct the airway. Secretory hyperresponsiveness and mucus hypersecretion appear to be related to activation of the extracellular-regulated kinase 1/2, signaling through the epidermal growth factor receptor, or secretory phospholipases A2. Recognizing secretory hyperresponsiveness as a distinct clinical entity may lead to more effective and targeted therapy for these diseases.

Current and novel bronchodilators in respiratory disease

PURPOSE OF REVIEW

β2-Agonists and muscarinic antagonists are widely used to treat asthma and chronic obstructive pulmonary disease (COPD), and a number of novel drug targets are being investigated for potential clinical utility. This review will summarize current developments in the field.

RECENT FINDINGS

The clinical effectiveness of a number of once a day inhaled β2-agonists and muscarinic antagonists is a major advance providing sustained bronchodilation in asthma and COPD. The identification of novel targets (e.g. bitter taste receptor TASR2), the demonstration of clinical effectiveness of others [e.g. phosphodiesterase (PDE)3/4] and exploring the potential of inverse agonists/biased agonists are evidence of continuing interest in the development of novel bronchodilators.

SUMMARY

Novel long-acting β2-agonists (e.g. indacaterol, vilanterol, olodaterol and carmoterol) and muscarinic antagonists (e.g. tiotropium, aclidinium, glycopyrronium and umeclidinium bromide) document sustained bronchodilation and their combination provides additional benefits over monotherapy. Not surprisingly, inhaled long-acting β2-agonist and long-acting muscarinic antagonists remain the drugs of choice for maintenance bronchodilation. However, there is a continued interest in developing novel bronchodilators illustrated by the clinical effectiveness of long acting mixed PDE3/4 inhibitors, vasointestinal peptide adenylyl cyclase agonists and inverse agonists/biased agonists for the β2-adrenoceptor, and the identification of intracellular (e.g. Rho kinase, exchange proteins activated by cyclic AMP) and cell surface (e.g. TAS2R, natriuretic peptide receptor) targets.

Cigarette smoke alters non-neuronal cholinergic system components inducing MUC5AC production in the H292 cell line

Cigarette smoke extract (CSE) affects the expression of Choline Acetyl-Transferase (ChAT), muscarinic acetylcholine receptors, and mucin production in bronchial epithelial cells. Mucin 5AC (MUC5AC), muscarinic acetylcholine receptor M3, ChAT expression, acetylcholine levels and acetylcholine binding were measured in a human pulmonary mucoepidermoid carcinoma cell line (H292) stimulated with CSE. We performed ChAT/RNA interference experiments in H292 cells stimulated with CSE to study the role of ChAT/acetylcholine in MUC5AC production. The effects of Hemicholinium-3 (HCh-3) (50 μM) (a potent and selective choline uptake blocker) and Tiotropium bromide (Spiriva(®)) (100 nM), alone or in combination with Salmeterol (SL) and Fluticasone propionate (FP), were tested in this model. MUC5AC, muscarinic acetylcholine receptor M3, ChAT, acetylcholine expression and acetylcholine binding significantly increased in H292 cells stimulated with CSE (5%) compared to untreated cells. HCh-3 reduced acetylcholine binding and MUC5AC production in H292 cells stimulated with CSE. ChAT/RNA interference eliminated the effect of CSE on MUC5AC production. FP reduced ChAT and acetylcholine binding in unstimulated cells, while showing a partial effect in CSE stimulated cells. SL increased the ChAT expression and acetylcholine binding in H292 cells stimulated with or without CSE. Tiotropium, alone or together with FP and SL, reduced acetylcholine binding and MUC5AC production in H292 cells stimulated with CSE. CSE affects the ChAT/acetylcholine expression, increasing MUC5AC production in H292 cells. Pharmacological treatment with anticholinergic drugs reduces the secretion of MUC5AC generated by autocrine acetylcholine activity in airway epithelial cells.

Is there a rationale and role for long-acting anticholinergic bronchodilators in asthma?

Despite current guidelines and the range of available treatments, over a half of patients with asthma continue to suffer from poor symptomatic control and remain at risk of future worsening. Although a number of non-pharmacological measures are crucial for good clinical management of asthma, new therapeutic controller medications will have a role in the future management of the disease. Several long-acting anticholinergic bronchodilators are under investigation or are available for the treatment of respiratory diseases, including tiotropium bromide, aclidinium bromide, glycopyrronium bromide, glycopyrrolate and umeclidinium bromide, although none is yet licensed for the treatment of asthma. A recent Phase III investigation demonstrated that the once-daily long-acting anticholinergic bronchodilator tiotropium bromide improves lung function and reduces the risk of exacerbation in patients with symptomatic asthma, despite the use of inhaled corticosteroids (ICS) and long-acting β₂-agonists (LABAs). This has prompted the question of what the rationale is for long-acting anticholinergic bronchodilators in asthma. Bronchial smooth muscle contraction is the primary cause of reversible airway narrowing in asthma, and the baseline level of contraction is predominantly set by the level of ‘cholinergic tone’. Patients with asthma have increased bronchial smooth muscle tone and mucus hypersecretion, possibly as a result of elevated cholinergic activity, which anticholinergic compounds are known to reduce. Further, anticholinergic compounds may also have anti-inflammatory properties. Thus, evidence suggests that long-acting anticholinergic bronchodilators might offer benefits for the maintenance of asthma control, such as in patients failing to gain control on ICS and a LABA, or those with frequent exacerbations.

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.