Airway responsiveness to adenosine after a single dose of fluticasone propionate discriminates asthma from COPD.

Background: Regular treatment with inhaled corticosteroids (ICS) is known to reduce airway hyperresponsiveness (AHR) to adenosine 5'-monophosphate (AMP) in asthma even after a single dose of fluticasone propionate (FP).

Aim: To determine whether this rapid protective effect of a single dose of FP is also present in COPD.

Methods: 23 mild asthmatic and 24 COPD subjects with documented AHR to both AMP and methacholine took part in a randomized, double-blind, placebo-controlled, crossover study to measure AHR to inhaled AMP and methacholine 2 h after either 1000 μg FP or matched placebo.