A randomized, double-blind, placebo-controlled study assessing the safety and tolerability of regadenoson in subjects with asthma or chronic obstructive pulmonary disease

BACKGROUND Adenosine receptor stress agents for myocardial perfusion imaging (MPI) may cause A(2B) and/or A(3) receptor-mediated bronchoconstriction, of particular concern to physicians testing patients with asthma or chronic obstructive pulmonary disease (COPD). METHODS A Phase 4, randomized, double-blind study (NCT00862641) assessed the safety of the selective A(2A) receptor agonist, regadenoson, compared with placebo in subjects with asthma or COPD who represented likely candidates for MPI. RESULTS Overall, 356 and 176 subjects with asthma and 316 and 151 subjects with COPD received regadenoson and placebo, respectively. The percentage of subjects experiencing a >15% decrease in FEV(1) from baseline to any assessment up to 24 hours post-baseline was not statistically significantly different between the regadenoson and the placebo groups in the asthma or COPD stratum. Dyspnea, the most frequent respiratory adverse event, occurred with higher incidence (P < .0001) in the regadenoson group than the placebo group in the asthma (10.7% vs 1.1%) and COPD (18.0% vs 2.6%) strata. No subjects experienced severe bronchoconstriction, although the occurrence of such reactions with adenosine receptor agonists cannot be ruled out, such that caution is advised. CONCLUSIONS This information may be helpful to physicians selecting a pharmacologic stress agent for MPI in patients with asthma or COPD.