BRONCHOPROTECTIVE EFFECT OF VILANTEROL AGAINST METHACHOLINE-INDUCED BRONCHOCONSTRICTION IN MILD ASTHMATICS: A RANDOMIZED THREE-WAY CROSSOVER STUDY

Publication date: Available online 12 July 2018

Source: Annals of Allergy, Asthma & Immunology

Author(s): Grace L.M. Westbury, Christianne M. Blais, Beth E. Davis, Donald W. Cockcroft

Abstract

Background

Ultra-long acting β2 agonists (uLABA) are relatively new anti-asthma medications of which there are three different formulations currently available: olodaterol, indacaterol and vilanterol. The first two formulations have been shown to exert bronchoprotective effects; they are able to prevent airway smooth muscle contraction upon exposure to constricting stimuli. However, studies have found that these two drugs produce different degrees and durations of bronchoprotection against methacholine.

Objective

The objective of this study was to investigate the degree of bronchoprotection provided by vilanterol against methacholine-induced bronchoconstriction.

Methods

Fourteen mild-to-moderate asthmatics [8 male; baseline percent predicted forced expiratory volume in 1 second (FEV1) > 65%; provocative concentration of methacholine causing a 20% reduction in FEV1 (PC20) ≤ 8mg/mL] completed this randomized, double-blind, three-way crossover study. Methacholine challenges were performed before treatment administration (placebo, 100μg fluticasone furoate, or 25μg vilanterol+100μg fluticasone furoate) and at 0.5 and 24 hours posttreatment. Each treatment arm was separated by a minimum 7-day wash-out period. A combination therapy of vilanterol+fluticasone furoate was used, as vilanterol is not available as a monotherapy.

Results

Significant bronchoprotection was evident following the combination treatment at both 0.5 and 24 hours with doubling dose shifts in methacholine PC20 of 2.0 (p=0.0004) and 1.6 (p=0.0001), respectively. Clinically significant bronchodilation was only recorded at 24 hours post-combination treatment (p<0.05).

Conclusion

These findings suggest that vilanterol (in combination with fluticasone furoate) provides significant bronchoprotection against methacholineinduced bronchoconstriction for at least 24 hours in mild-to-moderate asthmatics.

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