Background: Patients with reactive airways are at risk for adenosine-induced bronchoconstriction, mediated via A(2B) and/or A(3) adenosine receptors.
Methods And Results: In this randomized, double-blind, placebo-controlled crossover trial, we examined the safety of regadenoson, a selective adenosine A(2A) receptor agonist, in patients with moderate chronic obstructive pulmonary disease (COPD) (n = 38) and patients with severe COPD (n = 11) with a baseline mean forced expiratory volume in 1 second (FEV(1)) of 1.74 +/- 0.