The efficacy and safety of different long-acting β2-agonists combined with inhaled glucocorticoid regimens in patients with asthma: a network meta-analysis

Differences in the effectiveness of single, dual, and triple inhaled corticosteroid therapy for reducing future risk of severe asthma exacerbation: A systematic review and network meta-analysis

Importance

The effectiveness of different combinations of inhaled corticosteroid (ICS) therapies in reducing severe exacerbations of adult asthma remains unclear.

Objective

This network meta-analysis (NMA) extensively evaluated the treatment effects of single ICS; dual ICS i.e., ICS/long-acting β2-adrenergic agonists (LABA); ICS/LABA as single maintenance and reliever therapy (SMART); and triple ICS, i.e., ICS/LABA/long-acting muscarinic antagonists (LAMA) in preventing severe asthma exacerbations.

Data sources

A systematic search of English databases, including PubMed and Web of Science, was conducted until December 31, 2022, using PRISMA-NMA.

Study selection

Using the PICOS criteria, the questions for this study were carefully selected so that the correct keywords could be identified.

Data extraction and synthesis

A pairwise meta-analysis was used to select trials based on the criteria for minimizing heterogeneity (I2). Subsequently, the "BUGSnet" package of R software was used to perform a Bayesian network meta-analysis.

Main outcome measures

The main outcome measures were risk rate and annualized rate ratio of severe asthma exacerbations.

Results

This review included 56 randomized control trials (RCTs; n = 78,171 patients). As the pairwise meta-analysis demonstrated that the annualized rate ratio of severe asthma exacerbation had moderate heterogeneity, we analyzed the risk rate of severe asthma exacerbation using a network meta-analysis. In terms of direct/indirect comparisons with non-ICS, single ICS, dual ICS, SMART, and triple ICS reduced severe asthma exacerbations by 34 %, 47 %, 58 %, and 57 %, respectively. SMART and triple ICS showed high effectiveness in reducing severe exacerbations.

Conclusion

AND RELEVANCE: SMART and triple ICS were ranked higher in effectiveness in reducing severe asthma exacerbations in comparison with other therapies, indicating that these are the most effective treatments for reducing the future risk of severe asthma exacerbations.

Effects of Asthma Medication Type on Asthma Exacerbation in a Real-World Setting

PURPOSE

Currently, there are multiple options for the pharmacological treatment of asthma. This study aimed to compare the effects of different asthma medications on exacerbation in a real-world setting.

MATERIALS AND METHODS

We retrospectively reviewed electronic medical records of asthma patients who visited the hospital from November 1, 2016 to October 31, 2019. The number of asthma exacerbations requiring administration of systemic steroids was the primary outcome. A time-varying Cox regression analysis was used to reflect the real-world setting: variable usage times, discontinuation, and switching of medication.

RESULTS

Among 937 patients with asthma, 228 (24.3%) experienced asthma exacerbation during the study period. Asthma exacerbation was observed in patients using short-acting β₂-agonists (SABA) alone (50.4% vs. 28.6%, p<0.001) as well as in patients not using inhaled corticosteroids (ICS) (58.8% vs. 40.3%, p<0.001), long-acting β₂-agonists (LABA) (54.8% vs. 36.1%, p<0.001), and leukotriene receptor antagonists (71.5% vs. 50.8%, p<0.001). A time-varying Cox regression analysis of asthma exacerbations according to the duration of asthma medication showed that SABA alone increased the risk of asthma exacerbation [hazard ratio (HR), 1.834; 95% confidence interval (CI), 1.299-2.588; p=0.001], whereas ICS-LABA decreased the risk (HR, 0.733; 95% CI, 0.538-0.997; p=0.048). However, in the subgroup analysis according to medication type, specific ingredients showed no significant differences.

CONCLUSION

In the real world, asthma medications affect asthma exacerbation variably according to the medication type.

Corticosteroid resistance in asthma: Cellular and molecular mechanisms

Inhaled glucocorticoids (GCs) are drugs widely used as treatment for asthma patients. They prevent the recruitment and activation of lung immune and inflammatory cells and, moreover, have profound effects on airway structural cells to reverse the effects of disease on airway inflammation. GCs bind to a specific receptor, the glucocorticoid receptor (GR), which is a member of the nuclear receptor superfamily and modulates pro- and anti-inflammatory gene transcription through a number of distinct and complementary mechanisms. Targets genes include many pro-inflammatory mediators such as chemokines, cytokines, growth factors and their receptors. Inhaled GCs are very effective for most asthma patients with little, if any, systemic side effects depending upon the dose. However, some patients show poor asthma control even after the administration of high doses of topical or even systemic GCs. Several mechanisms relating to inflammation have been considered to be responsible for the onset of the relative GC resistance observed in these patients. In these patients, the side-effect profile of GCs prevent continued use of high doses and new drugs are needed. Targeting the defective pathways associated with GC function in these patients may also reactivate GC responsiveness.