J Postgrad Med. 2012 Apr-Jun;58(2):140-6. doi: 10.4103/0022-3859.97177.


Single-photon emission computerized tomography for myocardial perfusion imaging (MPI) is a non-invasive technique. MPI is performed by subjecting the patient to exercise or by using a pharmacological stress agent. Regadenoson is a selective A 2A adenosine receptor agonist used when MPI with exercise is contraindicated. It binds to the A 2A receptor and stimulates adenylate cyclase, resulting in increased cAMP, which phosphorylates protein kinase A thereby opening the ATP-dependant potassium channels leading to hyperpolarization in the coronary vascular smooth muscle. After a single bolus dose of regadenoson 400 μg, a peak plasma concentration (C max) of 13.6 ng/mL is attained in 1-4 min, with a terminal half-life of 2 h. It has a quick onset, short duration sufficient enough for hyperemic response, with comparable efficacy to adenosine, but with fewer side-effects. The adverse effects of this drug are dyspnea, headache, flushing, chest pain and atrioventricular block. Regadenoson is used for MPI in patients with co-morbid conditions like mild-to-moderate reactive airway disease, obstructive lung disease and renal impairment.

Publication types

  • Review

MeSH terms

  • Adenosine A2 Receptor Antagonists / adverse effects
  • Adenosine A2 Receptor Antagonists / pharmacology*
  • Blood Flow Velocity / drug effects
  • Coronary Artery Disease / diagnosis*
  • Dose-Response Relationship, Drug
  • Half-Life
  • Heart Rate / drug effects
  • Humans
  • Hyperemia / chemically induced
  • Myocardial Perfusion Imaging / methods
  • Purines / adverse effects
  • Purines / pharmacology*
  • Pyrazoles / adverse effects
  • Pyrazoles / pharmacology*
  • Stress, Physiological / drug effects*
  • Vasodilator Agents / adverse effects
  • Vasodilator Agents / chemistry
  • Vasodilator Agents / pharmacology*


  • Adenosine A2 Receptor Antagonists
  • Purines
  • Pyrazoles
  • Vasodilator Agents
  • regadenoson