Immediate antiinflammatory effects of inhaled budesonide in patients with asthma.

Background: In patients with asthma, single doses of inhaled glucocorticosteroids (ICS) have been reported to have antiinflammatory actions that can be detected several hours after drug administration. However, the onset and duration of the effect have not been investigated. We therefore measured airway blood flow (Q.aw) as an index of airway inflammation to determine the time course and dose dependence of the antiinflammatory action of an ICS in 20 patients with moderate asthma receiving regular ICS treatment.Methods: Q.aw and spirometry were measured before and serially for 360 minutes after a single inhaled dose of 360 μg, 720 μg, and 1,440 μg budesonide or placebo as well as after four repetitive 720-μg budesonide doses given 30 minutes apart.Results: Baseline mean Q.aw was increased and FEV1 was decreased without significant differences among the 5 treatment days. After budesonide inhalation, there was a transient, dose-dependent decrease in mean Q.aw from 12 to 21%, with significant differences from...