Effects of adenosine A2A receptor low affinity agonist Regadenoson in patients with obstructive pulmonary disease, at risk for adenosine-induced bronchoconstriction mediated via A2B and/or A3 adenosine receptors.

摘要

The pharmaceutical Regadenoson (Lexiscan TM) Produced by Astellas Inc. Is currently in use as a pharmacological stress agent for myocardial perfusion imaging within the field of Nuclear Cardiology. Regadenoson is a selective A2A adenosine receptor agonist, and also has a low affinity for adenosine receptors which cause bronchoconstriction in patients with reactive airways mediated via A 2B and A3 adenosine receptors. In a study of 42 patients with mild to moderate asthma and/or moderate to severe COPD who had a positive adenosine monophosphate test, Regadenoson proved to be relatively safe and well tolerated by most patients (90%). Introduction Regadenoson is a selective A2 A-adenosine receptor agonist currently in use as a pharmacologic stress agent in myocardial perfusion imaging studies within Nuclear Medicine . It was approved by the United States Food and Drug Administration on April 10, 2008.8 Regadenoson is a low affinity agonist (Ki ≈ 1.3 μM) for the A2A adenosine receptor, with at least 10-fold lower affinity for the A1 adenosine receptor (Ki > 16.5 μM), and weak, if any, affinity for the A2B and A3 adenosine receptors.2,9 Activation of the A2A adenosine receptor by regadenoson produces coronary vasodilation8 and increases coronary blood flow (CBF). It produces maximal hyperemia quickly and maintains it for an optimal duration that is practical for radionuclide myocardial perfusion imaging.1,7 Regadenoson is delivered as a rapid bolus intravenously with no dose adjustment required by weight.4 Review Regadenoson is chemically described as adenosine, 2-[4-[(methylamino) carbonyl]-1H-pyrazol-1-yl]-, monohydrate. The molecular formula for regadenoson is C15H18N8O5? H2O and its molecular weight is 408.37.4,5 Its structural formula is: