The investigators propose a 3-treatment, placebo-controlled, double-dummy, double-blinded, randomized, crossover study in which single doses of placebo, will be compared to Fluticasone propionate (Flovent Diskus) 250 mcg and budesonide 400 mcg administered after allergen challenge, at cessation of the early allergic reaction (at 20% fall in FEV1 from post-allergen peak)
The aim of this pilot study is to evaluate whether fluticasone propionate affects the late allergic reaction after a single dose post-allergen challenge administered following cessation of the early allergic reaction. Six subjects with mild asthma will be asked to volunteer for the study.The diagnosis of asthma will be and includes the presence of variable airflow limitation and AHR (PC20 methacholine \< 16 mg/mL). Subjects will be asked to participate if they demonstrate an allergen-induced early and late asthmatic response of at least 20% and 15% reduction in FEV1, respectively. The study will consist of 4 periods, composed of a screening allergen period with 3 subsequent allergen challenge/treatment periods. Each period will be separated with a washout of at least 2 weeks. Subjects who demonstrate a dual asthmatic response in the screening period will be selected for randomization to treatment.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
DOUBLE
Enrollment
7
McMaster University
Hamilton, Ontario, Canada
The Magnitude of the Early Asthmatic Response, Expressed as a Percentage Change in FEV1.
Time frame: Before inhalation 3 hours
The Magnitude of the Late Asthmatic Response, Expressed as a Percentage Change in FEV1.
Time frame: 7 hours after challenge
The Magnitude of Allergen-induced Airway Hyperresponsiveness (Methacholine PC20) and Inflammation (Sputum Eosinophils).
Time frame: Before inhalation both evaluations (0 hours)
The Magnitude of Allergen-induced Airway Hyperresponsiveness (Methacholine PC20) and Inflammation (Sputum Eosinophils)
Time frame: sputum @ 7 hours
The Magnitude of Allergen-induced Airway Hyperresponsiveness (Methacholine PC20) and Inflammation (Sputum Eosinophils)
Time frame: 24 hours methacholine and sputum
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