Benefits of low-dose inhaled fluticasone on airway response and inflammation in mild asthma

Summary

Rationale

Current guidelines suggest that asthma should be controlled with the lowest dose of maintenance medication required.

Objectives

To evaluate the effects of a low dose of inhaled corticosteroid compared to a placebo, on airway inflammation and responsiveness in patients with mild symptomatic asthma.

Methods

In this randomized double-blind, placebo-controlled, parallel group study, we looked at the influence of inhaled fluticasone propionate 250 μg/day for 3 months followed by 100 μg/day for 9 months on airway inflammation and methacholine responsiveness in non-smoking subjects with mild allergic asthma. Subjects were evaluated at baseline and 3, 6, 9 and 12 months after treatments; a 2-week evaluation of respiratory symptoms and peak expiratory flow measurements was done before each visit.

Results

Fifty-seven subjects completed the 3-month study period. Airway responsiveness, expressed as the PC₂₀ methacholine, increased by 0.27 and 1.14 doubling concentrations, respectively, in placebo-treated (n = 33) and in fluticasone-treated (n = 24) asthmatic subjects (p = 0.03). An additional improvement in PC₂₀ up to 2.16 doubling concentrations was observed in the fluticasone-treated group during the 9-month lower-dose treatment (p = 0.0004, end of low-dose period compared with placebo). Sputum eosinophil counts decreased after 3 months of fluticasone 250 μg/day compared with placebo (p < 0.0001) and remained in the normal range during the 9-month lower-dose treatment. Respiratory symptoms and peak expiratory flows did not change significantly throughout the study in both groups.

Conclusion

In mild asthma, keeping a regular minimal dose of ICS after asthma control has been achieved, may lead to a further reduction in airway responsiveness and keep sputum eosinophil count within the normal range.