Benefits of low-dose inhaled fluticasone on airway response and inflammation in mild asthma.
BACKGROUND
Current guidelines suggest that asthma should be controlled with the lowest dose of maintenance medication required.


OBJECTIVE
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 microg/day for 3 months followed by 100 microg/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 microg/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.


CONCLUSIONS
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.
Boulet
Louis-Philippe
LP
Unité de recherche en pneumologie, Institut universitaire de cardiologie et de pneumologie de Québec, 2725 Chemin Sainte-Foy, Québec8, PQ, Canada G1V 4G5. lpboulet@med.ulaval.ca
Turcotte
Hélène
H
Prince
Philippe
P
Lemière
Catherine
C
Olivenstein
Ronald
R
Laprise
Catherine
C
Larivée
Pierre
P
Bégin
Paul
P
Laviolette
Michel
M
D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D000730:Androstadienes / Q000008:administration & dosage*; D001249:Asthma / Q000188:drug therapy / Q000503:physiopathology*; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D000068298:Fluticasone; D005541:Forced Expiratory Volume / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D055815:Young Adult
D000730:Androstadienes; D001993:Bronchodilator Agents; D000068298:Fluticasone