Managing Severe Asthma: A Role for the Long-Acting Muscarinic Antagonist Tiotropium

Use of Biologic Therapies in the Treatment of Asthma – A Comparative Real World Data Analysis on Healthcare Resource Utilization and Costs Before and After Therapy Initiation

Background

Methods

Results

Conclusion

Understanding the role of long-acting muscarinic antagonists in asthma treatment

OBJECTIVE

Long-acting muscarinic antagonists (LAMAs) have been used in the treatment of obstructive pulmonary diseases for years. Long-acting muscarinic antagonists were previously mainly used as bronchodilators in chronic obstructive pulmonary disease, but the use of LAMAs in the treatment of asthma has gained great interest. There is now ample evidence of the efficacy and safety of LAMAs as add-on therapy to inhaled corticosteroid (ICS) plus long-acting β₂-agonist (LABA) combinations in patients with moderate to severe uncontrolled asthma. Long-acting muscarinic antagonists have subsequently been included in asthma guidelines. This review summarizes the scientific evidence on the use of LAMAs in asthma and aims to provide a better understanding of the role of LAMAs in the asthma treatment care algorithm and the current gaps in our knowledge.

DATA SOURCES

PubMed review using the following words: long-acting muscarinic antagonists, asthma, muscarinic receptors, tiotropium, glycopyrronium, umeclidinium.

STUDY SELECTIONS

This review focused on the key trials that led to the inclusion of LAMAs in asthma guidelines. In addition, we highlighted a number of studies with other study designs and populations.

RESULTS

We identified 6 major studies that led to inclusion in asthma guidelines and 3 studies with other study designs and populations.

CONCLUSION

Long-acting muscarinic antagonists add-on therapy to ICS-LABA improves lung function, reduces exacerbations, and modestly improves asthma control in patients with moderate to severe asthma who are uncontrolled despite the use of ICS-LABA. Long-acting muscarinic antagonists are effective in all asthma phenotypes and endotypes.

An Algorithm for Strategic Continuation or Restriction of Asthma Medication Prior to Exercise Challenge Testing in Childhood Exercise Induced Bronchoconstriction

Exercise induced bronchial (EIB) constriction is a common and highly specific feature of pediatric asthma and should be diagnosed with an exercise challenge test (ECT). The impact of EIB in asthmatic children's daily lives is immense, considering the effects on both physical and psychosocial development. Monitoring childhood asthma by ECT's can provide insight into daily life disease burden and the control of asthma. Current guidelines for bronchoprovocation tests restrict both the use of reliever and maintenance asthma medication before an exercise challenge to prevent false-negative testing, as both have significant acute bronchoprotective properties. However, restricting maintenance medication before an ECT may be less appropiate to evaluate EIB symptoms in daily life when a diagnosis of asthma is well established. Rigorous of maintenance medication before an ECT according to guidelines may lead to overestimation of the real, daily life asthma burden and lead to an inappropiate step-up in therapy. The protection against EIB offered by the combined acute and chronic bronchoprotective effects of maintenance medication can be properly assessed whilst maintaining them. This may aid in achieving the goal of unrestricted participation of children in daily play and sports activities with their peers without escalation of therapy. When considering a step down in medication, a strategic wash-out of maintenance medication before an ECT aids in providing objective support of potential discontinuation of maintenance medication.

Diagnosis and Management of Severe Asthma in Switzerland: Analysis of Survey Results Conducted with Specialists and General Practitioners

BACKGROUND

Severe asthma commonly affects 5-10% of the asthmatic population and accounts for approximately 50% of the overall asthma costs.

OBJECTIVE

This analysis investigated how severe asthma is diagnosed, treated, and managed by specialists and general practitioners (GPs) in Switzerland.

METHODS

Two surveys, one each among specialists (N = 44) and GPs (N = 153), were conducted to understand their self-perception on diagnosis, treatment, and management of severe asthma.

RESULTS

Fifty-five percent of the specialists felt very confident and 43% confident in recognizing the symptoms of severe asthma and diagnosing severe asthma. In contrast, 9% of the GPs were very confident and 59% confident in diagnosing severe asthma. More specific diagnostic tests for severe asthma, like total and specific immunoglobulin E levels and measurement of the fraction of exhaled nitric oxide, were run by specialists (χ2 = 171.4; df = 15, p < 0.001). GPs and specialists were using different measurements to assess severe asthma (χ2 = 385.2; df = 13, p < 0.001) and their prescribing patterns differed significantly (χ2 = 189.8; df = 10, p < 0.001). GPs referred patients with severe asthma if the diagnosis was unclear (24%), if treatment failure occurred (26%), and if the patients were at high risk (41%).

CONCLUSIONS

Oral corticosteroids (OCSs) are considered as background therapy for severe asthma by GPs and specialists. In order to reduce the OCS burden, there is a need to improve the awareness for other add-on therapies. A joint collaboration between GPs and specialists is the key to leverage therapeutic strategies together.

Organic Cation Transporters (OCTs) in EpiAirway™, A Cellular Model of Normal Human Bronchial Epithelium

Organic cation transporters (OCTs) and novel organic cation transporters (OCTNs) are responsible for drug delivery in the intestine and kidney; in the lung, OCTs mediate inhaled drugs’ transport, although their physiological role in airways remains poorly understood. The studies addressing OCTs/OCTNs in human airways were mostly performed in immortal or transformed cell lines; here, we studied OCTs in EpiAirway™, a recently developed in vitro model of normal bronchial epithelium. Calu-3 monolayers were used for comparison. The activity of OCTs was evaluated by measuring the uptake of 1-methyl-4-phenylpyridinium (MPP⁺) at the apical and basolateral side of monolayers and protein expression through Western Blot analysis. OCTs and OCTNs expression, along with that of Amino acid Transporter B^0,+ (ATB^0,+)transporter, was determined by measuring the number of mRNA molecules through quantitative Polymerase Chain Reaction (qPCR). The interaction of the transporters with bronchodilators was also assessed. Results highlight significant differences between Calu-3 cells and EpiAirway™, since, in the latter, OCTs are active only on the basolateral membrane where they interact with the bronchodilator ipratropium. No activity of OCTs is detectable at the apical side; there, the most abundant carrier is, instead, SLC6A14/ATB^0,+, that can thus be potentially listed among organic cation transporters responsible for drug delivery in the lung.