October 5, 2009 – A new analysis reaffirms that Lexiscan (regadenoson) Injection, the first selective A2A adenosine receptor agonist approved for use as a pharmacologic stress agent in radionuclide myocardial perfusion imaging (MPI) in patients unable to undergo adequate exercise stress, requires infrequent use of the drug aminophylline to reverse its effect in the case of adverse events.