Role of muscarinic antagonists in asthma therapy

New potent muscarinic receptor ligands bearing the 1,4-dioxane nucleus: Investigation on the nature of the substituent in position 2

A new series of muscarinic acetylcholine receptor (mAChR) ligands obtained by inserting different substituents in position 2 of the potent 6,6-diphenyl-1,4-dioxane antagonists 4 and 5 was designed and synthesized to investigate the influence of steric bulk on the mAChR affinity. Specifically, the insertion of a 2-methyl group, affording compounds 6 and 9, resulted as the most favorable modification in terms of affinity for all muscarinic subtypes. As supported by computational studies performed on the hM1 receptor, this substituent may contribute to stabilize the ligand within the binding site by favoring the formation of stable interactions between the cationic head of the ligand and the residue D105. The increase of steric bulk, obtained by replacing the methyl group with an ethyl (7 and 10) and especially a phenyl substituent (8 and 11), caused a marked decrease of mAChR affinity, demonstrating the crucial role played by the steric bulk of the 2-substituent in the mAChR interaction. The most intriguing result was obtained with the tertiary amine 9, which, surprisingly, showed two different pKi values for all mAChRs, with preferential subpicomolar affinities for the M1, M3, and M4 subtypes. Interestingly, biphasic curves were also observed with both the eutomer (S)-(-)-9 and the distomer (R)-( + )-9.

Activated non-neuronal cholinergic system correlates with non-type 2 inflammation and exacerbations in severe asthma

BACKGROUND

Non-neuronal cholinergic system (NNCS) contributes to various inflammatory airway diseases. However, the role of NNCS in severe asthma (SA) remains largely unexplored.

OBJECTIVE

To explore airway NNCS in SA.

METHODS

In this prospective cohort study based on the Australasian Severe Asthma Network in a real-world setting, patients with SA (n = 52) and non-SA (n = 104) underwent clinical assessment and sputum induction. The messenger RNA (mRNA) levels of NNCS components and proinflammatory cytokines in the sputum were detected using real-time quantitative polymerase chain reaction, and the concentrations of acetylcholine (Ach)-related metabolites were evaluated using liquid chromatography coupled with tandem mass spectrometry. Asthma exacerbations were prospectively investigated during the next 12 months. The association between NNCS and future asthma exacerbations was also analyzed.

RESULTS

Patients with SA were less controlled and had worse airway obstruction, a lower bronchodilator response, higher doses of inhaled corticosteroids, and more add-on treatments. The sputum mRNA levels of NNCS components, such as muscarinic receptors M1R-M5R, OCT3, VACHT, and ACHE; proinflammatory cytokines; and Ach concentration in the SA group were significantly higher than those in the non-SA group. Furthermore, most NNCS components positively correlated with non-type (T) 2 inflammatory profiles, such as sputum neutrophils, IL8, and IL1B. In addition, the mRNA levels of sputum M2R, M3R, M4R, M5R, and VACHT were independently associated with an increased risk of moderate-to-severe asthma exacerbations.

CONCLUSION

This study indicated that the NNCS was significantly activated in SA, leading to elevated Ach and was associated with clinical features, non-T2 inflammation, and future exacerbations of asthma, highlighting the potential role of the NNCS in the pathogenesis of SA.

CLINICAL TRIAL REGISTRATION

ChiCTR-OOC-16009529 (http://www.chictr.org.cn).

The New Paradigm: The Role of Proteins and Triggers in the Evolution of Allergic Asthma

Epithelial barrier damage plays a central role in the development and maintenance of allergic inflammation. Rises in the epithelial barrier permeability of airways alter tissue homeostasis and allow the penetration of allergens and other external agents. Different factors contribute to barrier impairment, such as eosinophilic infiltration and allergen protease action-eosinophilic cationic proteins' effects and allergens' proteolytic activity both contribute significantly to epithelial damage. In the airways, allergen proteases degrade the epithelial junctional proteins, allowing allergen penetration and its uptake by dendritic cells. This increase in allergen-immune system interaction induces the release of alarmins and the activation of type 2 inflammatory pathways, causing or worsening the main symptoms at the skin, bowel, and respiratory levels. We aim to highlight the molecular mechanisms underlying allergenic protease-induced epithelial barrier damage and the role of immune response in allergic asthma onset, maintenance, and progression. Moreover, we will explore potential clinical and radiological biomarkers of airway remodeling in allergic asthma patients.

Exercise-Induced Asthma: Managing Respiratory Issues in Athletes

Asthma is a complex respiratory condition characterized by chronic airway inflammation and variable expiratory airflow limitation, affecting millions globally. Among athletes, particularly those competing at elite levels, the prevalence of respiratory conditions is notably heightened, varying between 20% and 70% across specific sports. Exercise-induced bronchoconstriction (EIB) is a common issue among athletes, impacting their performance and well-being. The prevalence rates vary based on the sport, training environment, and genetics. Exercise is a known trigger for asthma, but paradoxically, it can also improve pulmonary function and alleviate EIB severity. However, athletes' asthma phenotypes differ, leading to varied responses to medications and challenges in management. The unique aspects in athletes include heightened airway sensitivity, allergen, pollutant exposure, and temperature variations. This review addresses EIB in athletes, focusing on pathogenesis, diagnosis, and treatment. The pathogenesis of EIB involves complex interactions between physiological and environmental factors. Airway dehydration and cooling are key mechanisms, leading to osmotic and thermal theories. Airway inflammation and hyper-responsiveness are common factors. Elite athletes often exhibit distinct inflammatory responses and heightened airway sensitivity, influenced by sport type, training, and environment. Swimming and certain sports pose higher EIB risks, with chlorine exposure in pools being a notable factor. Immune responses, lung function changes, and individual variations contribute to EIB in athletes. Diagnosing EIB in athletes requires objective testing, as baseline lung function tests can yield normal results. Both EIB with asthma (EIBA) and without asthma (EIBwA) must be considered. Exercise and indirect bronchoprovocation tests provide reliable diagnoses. In athletes, exercise tests offer effectiveness in diagnosing EIB. Spirometry and bronchodilation tests are standard approaches, but the diagnostic emphasis is shifting toward provocation tests. Despite its challenges, achieving an optimal diagnosis of EIA constitutes the cornerstone for effective management, leading to improved performance, reduced risk of complications, and enhanced quality of life. The management of EIB in athletes aligns with the general principles for symptom control, prevention, and reducing complications. Non-pharmacological approaches, including trigger avoidance and warming up, are essential. Inhaled corticosteroids (ICS) are the cornerstone of asthma therapy in athletes. Short-acting beta agonists (SABA) are discouraged as sole treatments. Leukotriene receptor antagonists (LTRA) and mast cell stabilizing agents (MCSA) are potential options. Optimal management improves the athletes' quality of life and allows them to pursue competitive sports effectively.

The Role of Long-Acting Antimuscarinic Agents in the Treatment of Asthma

The journey of using anticholinergics in the treatment of asthma started with anticholinergic-containing plants such as Datura stramonium and Atropa belladonna, followed by ipratropium bromide and continued with tiotropium, glycopyrronium, and umeclidinium. Although antimuscarinics were used in the maintenance treatment of asthma over a century ago, after a long time (since 2014), it has been recommended to be used as an add-on long-acting antimuscarinic agent (LAMA) therapy in the maintenance treatment of asthma. The airway tone controlled by the vagus nerve is increased in asthma. Allergens, toxins, or viruses cause airway inflammation and inflammation-related epithelial damage, increased sensory nerve stimulation, ganglionic and postganglionic acetylcholine (ACh) release by inflammatory mediators, intensification of ACh signaling at M1 and M3 muscarinic ACh receptors (mAChRs), and dysfunction of M2 mAChR. Optimal anticholinergic drug for asthma should effectively block M3 and M1 receptors, but have minimal effect on M2 receptors. Tiotropium, umeclidinium, and glycopyrronium are anticholinergic agents with this feature. Tiotropium has been used in a separate inhaler as an add-on treatment to inhaled corticosteroid (ICS)/long-acting β2-agonist (LABA), and glycopyrronium and umeclidinium have been used in a single inhaler as a combination of ICS/LABA/LAMA in asthma in recent years. Guidelines recommend this regimen as an optimization step for patients with severe asthma before initiating any biologic or systemic corticosteroid therapy. In this review, the history of antimuscarinic agents, their effectiveness and safety in line with randomized controlled trials, and real-life studies in asthma treatment will be discussed according to the current data.

Revisiting asthma pharmacotherapy: where do we stand and where do we want to go?

Several current guidelines/strategies outline a treatment approach to asthma, which primarily consider the goals of improving lung function and quality of life and reducing symptoms and exacerbations. They suggest a strategy of stepping up or down treatment, depending on the patient's overall current asthma symptom control and future risk of exacerbation. While this stepwise approach is undeniably practical for daily practice, it does not always address the underlying mechanisms of this heterogeneous disease. In the last decade, there have been attempts to improve the treatment of severe asthma, such as the addition of a long-acting antimuscarinic agent to the traditional inhaled corticosteroid/long-acting β2-agonist treatment and the introduction of therapies targeting key cytokines. However, despite such strategies several unmet needs in this population remain, motivating research to identify novel targets and develop improved therapeutic and/or preventative asthma treatments. Pending the availability of such therapies, it is essential to re-evaluate the current conventional "one-size-fits-all" approach to a more precise asthma management. Although challenging, identifying "treatable traits" that contribute to respiratory symptoms in individual patients with asthma may allow a more pragmatic approach to establish more personalised therapeutic goals.

Might It Be Appropriate to Anticipate the Use of Long-Acting Muscarinic Antagonists in Asthma?

A growing number of clinical trials are documenting that adding a long-acting muscarinic antagonist (LAMA) to established asthma treatment with an inhaled corticosteroid (ICS) and a long-acting β₂-agonist (LABA) is a treatment option that improves the health of patients with uncontrolled severe asthma even when therapy is optimized. These favorable results are the reason why the leading guidelines recommend triple therapy with ICS + LABA + LAMA in patients with asthma uncontrolled by medium- to high-dose ICS-LABA. However, we suggest adding LAMAs to ICS-LABAs at an earlier clinical stage. Such action could positively influence airflow limitation, exacerbations, and eosinophilic inflammation, conditions that are associated with acetylcholine (ACh) activity. It could also interrupt the vicious cycle related to a continuous release of ACh leading to the progressive expansion of neuronal plasticity resulting in small airway dysfunction. The utility of an earlier use of triple therapy in asthma should, in any case, be confirmed by statistically powered trials.

The Efficacy and Safety of First-Line Single-Inhaler Triple versus Dual Therapy in Controller-Naïve and Symptomatic Adults with Asthma: A Preliminary Retrospective Cohort Study

Purpose

The efficacy and safety of first-line triple and dual therapy remain unclear because the stepwise strategy is a worldwide standard in controller-naïve asthma. A preliminary retrospective cohort study was conducted to investigate the efficacy and safety of first-line triple and dual therapy for managing controller-naïve and symptomatic adult patients with asthma.

Patients and Methods

Patients with asthma who received first-line single-inhaler triple therapy (SITT) or dual therapy (SIDT) for at least 8 weeks were selected between December 1, 2020, and May 31, 2021, in Fujiki Medical and Surgical Clinic, Miyazaki, Japan. Data on daytime and nighttime visual analog scale (VAS) scores, lung function tests, fractional exhaled nitrogen oxide (F_ENO), and adverse events were compared between SITT and SIDT pre- and post-treatment.

Results

The SITT significantly improved the nighttime, but not daytime, VAS scores better than the SIDT 2 weeks post-treatment (P = 0.0026), whereas SITT and SIDT significantly improved daytime and nighttime VAS scores after treatment compared to baseline. Both therapies also significantly improved lung functions and F_ENO post-treatment. The proportion of patients achieving complete control in the nighttime VAS scores after SITT was significantly higher than that four (P = 0.0186) and 8 weeks (P = 0.0061) after SIDT. Only patients with SITT experienced dry mouth.

Conclusion

Our study demonstrated that first-line SITT and SIDT were effective, and SITT improved disease control faster than SIDT in controller-naïve and symptomatic adult patients with asthma. The first-line SITT may contribute to faster and better control levels in symptomatic patients with asthma.

Clinical characteristics, treatment patterns and adherence in patients with asthma on multiple inhaler triple therapy: a review of findings

INTRODUCTION

The value of treating asthma with the triple regimen of inhaled corticosteroid (ICS), long-acting β2-agonist (LABA), and long-acting muscarinic antagonist (LAMA) delivered using multiple inhalers (MITT), or a single inhaler (SITT) is supported by a growing body of evidence, although research is still limited regarding the use of MITT.

AREAS COVERED

Clinical characteristics, treatment patterns, disease burden, and persistence/adherence associated with MITT use in asthma. The MEDLINE database was searched to identify references from inception until October 2022.

EXPERT OPINION

The use of MITT is not very frequent in asthma patients, although it improves lung function and reduces the incidence of severe exacerbations. This may be due to existing concerns about using different devices on adherence and persistence to treatment, with a negative influence on outcomes, and to the fear that the patient will discontinue ICS/LABA but not LAMA. Nevertheless, although the current trend favors the SITT approach, some physicians may be induced to prescribe MITT over SITT because it allows the titration of individual components of triple therapy to be increased or decreased. Therefore, there is an evident need for pragmatic real-life studies to document when to prefer SITT and when MITT should be used.

Tiotropium Add-On and Treatable Traits in Asthma-COPD Overlap: A Real-World Pilot Study

Purpose

The 'treatable traits' strategy for patients with chronic inflammatory airway diseases, especially asthma and chronic obstructive pulmonary disease (COPD), is a focus of interest, because it implements precision and personalized medicine. Asthma-COPD overlap (ACO), a phenotype involving both asthma and COPD, is an important disease entity because patients with ACO have significantly worse outcomes, conferring greater economical and social burdens. Some guidelines for ACO recommend add-on therapy of long-acting muscarinic antagonists to inhaled corticosteroids and long-acting β2 agonists. However, this approach is based on extrapolation from patients with asthma or COPD alone. Consequently, a 'treatable traits' approach suitable for ACO remains obscure.

Methods

A 12-week open-label cross-over pilot study was conducted in patients with ACO to investigate the effect of tiotropium bromide (TIO) 5 µg/day add-on therapy to fluticasone propionate/formoterol fumarate (FP/FM) 500/20 µg/day compared with FP/FM 500/20 µg/day alone. A 4-week run-in period and two 4-week treatment periods were included.

Results

A total of 18 male patients with stable ACO participated in this pilot study. All patients were ex-smokers. Mean values ± standard deviation (SD) for forced expiratory volume in 1 second (FEV1) were 1.21 ± 0.49 L after the run-in period, 1.20 ± 0.51 L after the FP/FM combination therapy period, and 1.30 ± 0.48 L after the TIO add-on therapy to FP/FM period. FEV1 values after the TIO add-on therapy FP/FM period were significantly higher than those after the run-in period (p < 0.01).

Conclusion

TIO add-on therapy to FP/FM in patients with ACO, considered difficult to treat because of the presence of both asthma and COPD, resulted in improvements in lung function parameters in this real-world pilot study, indicating the potential value of TIO add-on therapy as a "treatable traits" option for standard treatment for ACO.

Current long-acting muscarinic antagonists for the treatment of asthma

INTRODUCTION

The role of long-acting muscarinic antagonists (LAMAs) is well established in uncontrolled asthma, but not in milder stages.

AREAS COVERED

This review examines the main randomized controlled trials (RCTs) that have investigated LAMAs administered as monotherapy or in combination to asthmatic patients, according to the different phenotypes. It offers an overview of the role of LAMAs or their fixed dose combinations (FDCs) in the treatment across all the different stages of asthma.

EXPERT OPINION

Tiotropium is now widely recognized as treatment for moderate to severe uncontrolled asthma (step 4-5) in adults and children. The most recent new evidence is: a) in adults, three different LAMA/long-acting β₂-agonist (LABA)/inhaled corticosteroid (ICS) FDCs have been recently approved, extending the treatment options for these patients; b) therapy with LAMAs does not depend on patient's Th2 status and justifies the indication regardless of patient's phenotyping; c) in the milder stages, the high variability of response to LAMAs and the lack of a good phenotyping of patients represents the main obstacle in prescribing LAMAs. A better characterization of parasympathetic tone activity could improve LAMAs prescription.

Novel pharmacological therapies for the treatment of bronchial asthma

Asthma has long been recognised as a chronic inflammatory disease of the airways, often in response to inhaled allergens prompting inappropriate activation of the immune response. involving a range of cells including mast cells, Th2 lymphocytes and eosinophils and a wide range of inflammatory mediators. First-line therapy for treatment of persistent asthma involves the use of inhaled corticosteroids (ICS) in combination with inhaled β2-agonists enabling both the control of the underlying airways inflammation and a reduction of airway hyperresponsiveness. However, many patients remain symptomatic despite high-dose therapy. There is therefore a continued unmet clinical need to develop specifically new anti-inflammatory therapies for patients with asthma, either as an add-on therapy to ICS or as replacement monotherapies. The success of fixed dose combination inhalers containing both a bronchodilator and an anti-inflammatory drug has also led to the development of "bifunctional" drugs which are molecules specifically designed to have two distinct pharmacological actions based on distinct pharmacophores. In this review we will discuss these different pharmacological approaches under development for the treatment of bronchial asthma and the available pre-clinical and clinical data.

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.

Pharmacology and Therapeutics of Bronchodilators Revisited

Bronchodilators remain the cornerstone of the treatment of airway disorders such as asthma and chronic obstructive pulmonary disease (COPD). There is therefore considerable interest in understanding how to optimize the use of our existing classes of bronchodilator and in identifying novel classes of bronchodilator drugs. However, new classes of bronchodilator have proved challenging to develop because many of these have no better efficacy than existing classes of bronchodilator and often have unacceptable safety profiles. Recent research has shown that optimization of bronchodilation occurs when both arms of the autonomic nervous system are affected through antagonism of muscarinic receptors to reduce the influence of parasympathetic innervation of the lung and through stimulation of β ₂-adrenoceptors (β ₂-ARs) on airway smooth muscle with β ₂-AR-selective agonists to mimic the sympathetic influence on the lung. This is currently achieved by use of fixed-dose combinations of inhaled long-acting β ₂-adrenoceptor agonists (LABAs) and long-acting muscarinic acetylcholine receptor antagonists (LAMAs). Due to the distinct mechanisms of action of LAMAs and LABAs, the additive/synergistic effects of using these drug classes together has been extensively investigated. More recently, so-called "triple inhalers" containing fixed-dose combinations of both classes of bronchodilator (dual bronchodilation) and an inhaled corticosteroid in the same inhaler have been developed. Furthermore, a number of so-called "bifunctional drugs" having two different primary pharmacological actions in the same molecule are under development. This review discusses recent advancements in knowledge on bronchodilators and bifunctional drugs for the treatment of asthma and COPD. SIGNIFICANCE STATEMENT: Since our last review in 2012, there has been considerable research to identify novel classes of bronchodilator drugs, to further understand how to optimize the use of the existing classes of bronchodilator, and to better understand the role of bifunctional drugs in the treatment of asthma and chronic obstructive pulmonary disease.

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.

A review of the pharmacokinetics of M3 muscarinic receptor antagonists used for the treatment of asthma

Introduction: There is solid evidence that in patients with poorly controlled severe asthma despite the use of ICS and LABA, the addition of LAMAs, such as tiotropium, significantly increases the time to the first severe exacerbation and provides a modest but sustained bronchodilation. However, only a very limited number of pharmacokinetic studies with these agents have been performed in asthmatic patients.Areas covered: The pharmacokinetic profile of inhaled tiotropium, umeclidinium and glycopyrronium in healthy volunteers and that of inhaled tiotropium and umeclidinium in asthmatic patients have been reviewed.Expert opinion: In asthmatic patients, LAMAs are rapidly absorbed into the systemic compartment and demonstrate bi-exponential elimination (rapidly declining plasma concentrations followed by slow apparent terminal elimination). Apparently, the severity of asthma does not change the pharmacokinetics of LAMAs. The limited information available is focused on the plasma pharmacokinetic profile of these drugs and, consequently, although suitable for establishing a systemic safety profile, it does not tell us much about possible therapeutic efficacy of LAMAs in asthmatics because quantification of systemic plasma values is neither at the airways, which are their site of action nor representative of their transport to this site.

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.

A potential role of triple therapy for asthma patients

Introduction: The use of LAMAs in asthma is now supported by pharmacological and clinical evidence, whereas the effectiveness of therapy with ICS/LABA/LAMA fixed dose combinations in patients with asthma still remains to be determined. Areas covered: The pharmacological rationale that explains why it is possible to use triple therapy in asthma and the results of clinical studies that have explored the effects of this therapy in asthmatics is critically examined. A systematic search was conducted on 10 August 2019, and included six electronic databases: EMBASE, MEDLINE, Scopus, The Cochrane Library, Web of Science, and Google Scholar. Expert opinion: The real role of single inhaler triple therapy in asthma will be demonstrated when the various trials that are currently ongoing or are scheduled will be completed. We believe that it is appropriate to treat with triple therapy asthmatic patients who have smoked and remain symptomatic or suffer from frequent exacerbations despite initial inhaler therapy with ICS/LABA. However, we must establish when to step up or mainly step down triple therapy especially in patients who are well controlled, and what will be the cost of these combinations in the management of asthma.

Future perspectives of anticholinergics for the treatment of asthma in adults and children

Despite major advances in therapeutic interventions and the availability of detailed treatment guidelines, a high proportion of patients with symptomatic asthma remain uncontrolled. Asthma management is largely guided by the Global Initiative for Asthma (GINA) strategy and is based on a backbone of inhaled corticosteroid (ICS) therapy with the use of additional therapies to achieve disease control. Inhaled long-acting bronchodilators alone and in combination are the preferred add-on treatment options. Although long-acting muscarinic antagonists (LAMAs) are a relatively recent addition to disease management recommendations for asthma, tiotropium has been extensively studied in a large clinical trial program. In Europe and the United States, tiotropium is approved for patients aged ≥6 years and uncontrolled on medium- to high-dose ICS/long-acting β2-agonists at GINA Steps 4 and 5 with a history of exacerbations. Evidence supports the efficacy of tiotropium Respimat® in adults in terms of lung function and asthma control, with a safety profile comparable with that of placebo across a range of asthma severities. Similarly, clinical trials in patients aged 1-17 years have shown improvements in lung function and trends toward improved asthma control. Furthermore, its efficacy makes tiotropium relatively easy to incorporate into routine clinical practice, irrespective of allergic status and without the need for patient phenotyping. Tiotropium is a cost-effective treatment that may offer an important alternative to other, more expensive add-on therapies. This review discusses the potential future position of LAMAs in clinical practice by considering the continuously evolving evidence. Prominence is given to tiotropium, the only LAMA supported by a structured clinical trial program in asthma to date, while also considering other recommended treatment options for patients with uncontrolled asthma. The importance of effective patient/caregiver-clinician communication and shared decision-making in enhancing treatment adherence is also highlighted.

Barriers to achieving asthma control in adults: evidence for the role of tiotropium in current management strategies

Despite the availability of a range of treatment options and management guidelines, a high proportion of adults with asthma remain uncontrolled. The challenge of managing uncontrolled asthma includes providing efficacious treatment while limiting side effects, recognizing situations when a change in asthma therapy is required, and considering patient preferences and satisfaction. In line with the Global Initiative for Asthma report, asthma management is based on a backbone of inhaled corticosteroid (ICS) therapy and use of add-on therapies to achieve disease control. This review considers whether add-on options could be better utilized in clinical practice. A number of long-acting muscarinic antagonists are in development, but tiotropium is the most widely studied for use in asthma. Evidence demonstrating the efficacy of tiotropium as an add-on therapy to at least ICS in adults with symptomatic mild, moderate, and severe asthma is presented from randomized controlled trials and real-world evidence. In addition, the benefit of tiotropium therapy in a wide range of patient phenotypes and disease severities without the need for biomarker assessment is discussed. Additional strategies that complement this approach, such as recognizing and overcoming barriers to adherence, ensuring optimal device use, and education and support to enhance patient–physician communication, are discussed. Physician education can also help raise awareness that additional management options are available for patients with moderate-to-severe asthma who remain uncontrolled on ICS/long-acting β₂-agonist treatment.

Expression of Muscarinic Receptors and the Effect of Tiotropium Bromide in Aged Mouse Model of Chronic Asthma

BACKGROUND

Efficacy and safety of tiotropium bromide, a muscarinic receptor antagonist, in treatment of asthma have been reported. However, its effect on airway remodeling in chronic asthma of the elderly has not been clearly verified. The objective of this study was to investigate the effect of tiotropium and expression of muscarinic receptors as its related mechanism in an aged mouse model of chronic asthma with airway remodeling.

METHODS

BALB/c female mice age 6 weeks, 9 and 15 months were sensitized and challenged with ovalbumin (OVA) for three months. Tiotropium bromide was administered during the challenge period. Airway hyperresponsiveness (AHR) and pulmonary inflammation were measured. Parameters of airway remodeling, and expression levels of M₂ and M₃ receptors were examined.

RESULTS

Total cell with eosinophils, increased in the OVA groups by age, was decreased significantly after treatment with tiotropium bromide, particularly in the age group of 15 months. AHR and levels of interleukin (IL)-4, IL-5, and IL-13 were decreased, after tiotropium administration. In old aged group of 9- and 15-months-treated groups, hydroxyproline contents and levels of α-smooth muscle actin were attenuated. Tiotropium enhanced the expression of M₂ but decreased expression of M₃ in all aged groups of OVA.

CONCLUSION

Tiotropium bromide had anti-inflammatory and anti-remodeling effects in an aged mouse model of chronic asthma. Its effects seemed to be partly mediated by modulating expression M₃ and M₂ muscarinic receptors. Tiotropium may be a beneficial treatment option for the elderly with airway remodeling of chronic asthma.

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.

Efficacy and Safety of Tiotropium in Children and Adolescents

Asthma is one of the most common chronic diseases in children, with a high proportion of patients demonstrating poor control despite the availability of disease management guidelines. Global Initiative for Asthma guidelines include tiotropium as an add-on therapy option at Steps 4 and 5 in patients aged ≥ 12 years with a history of exacerbations, and tiotropium delivered via the Respimat® Soft Mist™ Inhaler has recently been approved for use as once-daily maintenance therapy for children with asthma over the age of 6 years in the USA. A large clinical trial program has been conducted in children, adolescents, and adults across the spectrum of asthma severity. Findings from these clinical studies and pooled analyses in children and adolescents with symptomatic moderate or severe asthma have demonstrated that tiotropium Respimat® as add-on to inhaled corticosteroids, with or without other maintenance therapies, is a well-tolerated and efficacious bronchodilator, showing improved lung function and trends towards improved asthma control, mirroring findings in adult studies. This review discusses the evidence to date for tiotropium Respimat® for the management of asthma in adolescents and children with symptomatic moderate and severe asthma, and considers the challenges of asthma management in these patients. Factors affecting this population group, such as poor adherence, underreporting of symptoms, and social and psychological issues, are highlighted, along with the need for active review and management of treatment to help achieve optimal control.

Pharmacogenetic and pharmacogenomic considerations of asthma treatment

INTRODUCTION

Pharmacogenetic and pharmacogenomic approaches are already utilized in some areas, such as oncology and cardiovascular disease, for selecting appropriate patients and/or establishing treatment and dosing guidelines. This is not true in asthma although many patients have different responses to drug treatment due to genetic factors. Areas covered: Several genetic factors that affect the pharmacotherapeutic responses to asthma medications, such as β₂-AR agonists, corticosteroids, and leukotriene modifiers and could contribute to significant between-person variability in response are described. Expert opinion: An expanding number of genetic loci have been associated with therapeutic responses to asthma drugs but the individual effect of one single-nucleotide polymorphism is partial. In fact, epigenetic changes can modify genetic effects in time-, environment-, and tissue-specific manners, genes interact together in networks, and nongenetic components such as environmental exposures, gender, nutrients, and lifestyle can significantly interact with genetics to determine the response to therapy. Therefore, well-designed randomized controlled trials or observational studies are now mandatory to define if response to asthma medications in individual patients can be improved by using pharmacogenetic predictors of treatment response. Meanwhile, routine implementation of pharmacogenetics and pharmacogenomics into clinical practice remains a futuristic, far-off challenge for many clinical practices.

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.