Loss of bronchoprotection with ICS plus LABA treatment, β-receptor dynamics, and the effect of alendronate

BACKGROUND

Loss of bronchoprotection (LOBP) with a regularly used long-acting β2-adrenergic receptor agonist (LABA) is well documented. LOBP has been attributed to β2-adrenergic receptor (B2AR) downregulation, a process requiring farnesylation, which is inhibited by alendronate.

OBJECTIVE

We sought to determine whether alendronate can reduce LABA-associated LOBP in inhaled corticosteroid (ICS)-treated patients.

METHODS

We conducted a randomized, double-blind, placebo-controlled, parallel-design, proof-of-concept trial. Seventy-eight participants with persistent asthma receiving 250 μg of fluticasone twice daily for 2 weeks were randomized to receive alendronate or placebo while initiating salmeterol for 8 weeks. Salmeterol-protected methacholine challenges (SPMChs) and PBMC B2AR numbers (radioligand binding assay) and signaling (cyclic AMP ELISA) were assessed before randomization and after 8 weeks of ICS plus LABA treatment. LOBP was defined as a more than 1 doubling dose reduction in SPMCh PC20 value.

RESULTS

The mean doubling dose reduction in SPMCh PC20 value was 0.50 and 0.27 with alendronate and placebo, respectively (P = .62). Thirty-eight percent of participants receiving alendronate and 33% receiving placebo had LOBP (P = .81). The after/before ICS plus LABA treatment ratio of B2AR number was 1.0 for alendronate (P = .86) and 0.8 for placebo (P = .15; P = .31 for difference between treatments). The B2AR signaling ratio was 0.89 for alendronate (P = .43) and 1.02 for placebo (P = .84; P = .44 for difference). Changes in lung function and B2AR number and signaling were similar between those who did and did not experience LOBP.

CONCLUSION

This study did not find evidence that alendronate reduces LABA-associated LOBP, which relates to the occurrence of LOBP in only one third of participants. LOBP appears to be less common than presumed in concomitant ICS plus LABA-treated asthmatic patients. B2AR downregulation measured in PBMCs does not appear to reflect LOBP.

Role of Montelukast in Improving Quality of Life in Patients with Persistent Asthma

Introduction

Maintenance therapy of asthma has a crucial role in keeping the disease dormant and preventing frequent acute exacerbations. Asthma control may be achieved by inhaled corticosteroids (ICS) and/or long-acting beta-agonists (LABA). Leukotriene receptor antagonist - montelukast - may be added as an add-on to ICS/LABA or may also be given in monotherapy. The aim of this study was to evaluate the role of montelukast monotherapy as asthma control and its impact on the quality of life of these patients.

Methods

In this prospective, open-label, interventional study, montelukast 10 mg once daily was given to patients with mild to moderate persistent asthma for four weeks. Quality of life (QOL) was assessed on the Asthma Quality of Life Questionnaire - Standard (AQLQ-S) questionnaire. Asthma control was assessed on the Asthma Control Test (ACT). Data was entered and analyzed using SPSS version 23.0.

Results

On AQLQ-S, overall QOL improved with one month of montelukast therapy significantly. On sub-scales, except for emotional function, all other three sub-scales including symptoms, activity limitation, and environmental function improved significantly. Asthma control score also significantly improved with one month of montelukast therapy.

Conclusion

Montelukast has an effective role in asthma control and improvement of QOL in patients with mild to moderate persistent asthma.

Weight status and nonadherence to asthma maintenance therapy among children enrolled in a public drug insurance plan

Objective: The pediatric obese-asthma phenotype is associated with poor control, perhaps because of medication nonadherence. This study aimed to assess whether weight status is associated with nonadherence in children prescribed new asthma maintenance therapies.Methods: A historical cohort was constructed from a clinical database linking individual patient and prescription data to Quebec's prescription claims registry. Children aged 2-18 years with specialist-diagnosed asthma who were newly prescribed one of the following maintenance controllers: leukotriene receptor antagonists (LTRA); low-dose inhaled corticosteroids (ICS); medium/high-dose ICS; or combination therapy (ICS with long-acting beta-2 agonists and/or LTRA), at the Asthma Center of the Montreal Children's Hospital from 2000-2007 were included. Primary nonadherence was defined as not claiming any prescriptions, whereas secondary nonadherence was measured with the proportion of prescribed days covered (PPDC ≤ 50%) among primary adherers over a 6-month follow-up period. A modified Poisson regression model served to estimate the effect of excess weight (BMI > 85^th percentile) on primary and secondary nonadherence.Results: Approximately one third of patients were primary nonadherers and 60% took less than 50% of prescribed therapy. Excess weight was associated with a trend toward increased risk of primary nonadherence in children newly prescribed low-dose ICS (RR 1.53, 95%CI 0.94-2.49), and of secondary nonadherence in children initiating medium/high-dose ICS (RR 1.24; 95%CI 0.98-1.59).Conclusions: Excess weight status is a possible determinant of primary nonadherence in children initiating low-dose ICS and secondary nonadherence to higher-dose ICS regimens. This hypothesis-generating study suggests that nonadherence may be a potential contributor to higher morbidity in children with obese-asthma.

Severe and uncontrolled asthma in China: a cross-sectional survey from the Australasian Severe Asthma Network

BACKGROUND

Severe asthma is largely unexplored in the Chinese population. Patients with asthma underwent systematic evaluation, by investigating the characteristics of uncontrolled asthma and of asthma treated with three different controller therapies.

METHODS

This multi-centre, real-world study was conducted from March 2014 to September 2015. Adults with stable asthma underwent assessment of medication use, asthma control, quality of life, psychological symptoms, work productivity and activity impairment, bronchodilator response and sputum induction.

RESULTS

Participants (n=379) had a mean (SD) age of 47.4 (14.0) years, and 57.0% were female. There were 14.8% (n=56) of patients receiving treatment with Step 4/5 as severe asthma, but only 13 (3.4%) met ERS/ATS severe refractory asthma criteria. The patients with severe asthma usually used triple controller therapy: ICS/LABA, additional leukotriene modifier or theophylline, and reported better asthma control. Two fifths of patients (n=147) had uncontrolled asthma, with worse symptoms, psychological symptoms (both P<0.001), health-related work productivity and activity impairment, increased eosinophilic inflammation in sputum [1.68% (0.0, 17.1%) vs. 0.2% (0.0, 1.3%), P<0.0001] and more exacerbations (P<0.05). Multiple regression analysis indicated that triple controller therapy significantly reduced the risk of uncontrolled asthma [OR =0.32, 95% CI =(0.14, 0.75)].

CONCLUSIONS

Although there is a relatively low proportion of severe refractory asthma based on ERS/ATS criteria, two of five patients with asthma in China are uncontrolled, displaying more psychological symptoms and reduced work productivity. Substantial gain in asthma control is obtained by triple controller therapy and this may be a promising therapeutic option for persistent asthma.