Regadenoson is an adenosine derivative and selective A2A adenosine receptor agonist with coronary vasodilating activity. Upon administration, regadenoson selectively binds to and activates the A2A adenosine receptor, which induces coronary vasodilation. This leads to an increase in coronary blood flow and enhances myocardial perfusion. Compared to adenosine, regadenoson has a longer half-life and shows higher selectivity towards the A2A adenosine receptor. This agent is a very weak agonist for the A1 adenosine receptor and has negligible affinity for the A2B and A3 adenosine receptors.