Overview
11 DESCRIPTION Regadenoson is an A 2A adenosine receptor agonist that is a coronary vasodilator [see Clinical Pharmacology ( 12.1 ) ]. Regadenoson is chemically described as adenosine, 2-[4-[(methylamino)carbonyl]-1 H -pyrazol-1-yl].Its structural formula is: The molecular formula for regadenoson is C 15 H 18 N 8 O 5 and its molecular weight is 390.35.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Regadenoson is a low affinity agonist (K i ≈ 1.3 µM) for the A 2A adenosine receptor, with at least 10-fold lower affinity for the A 1 adenosine receptor (K i > 16.5 µM), and weak, if any, affinity for the A 2B and A 3 adenosine receptors. Activation of the A 2A adenosine receptor by regadenoson produces coronary vasodilation and increases coronary blood flow (CBF). 12.2 Pharmacodynamics Coronary Blood Flow Regadenoson causes a rapid increase in CBF which is sustained for a short duration. In patients undergoing coronary catheterization, pulsed-wave Doppler ultrasonography was used to measure the average peak velocity (APV) of coronary blood flow before and up to 30 minutes after administration of regadenoson (0.4 mg, intravenously).
Indications
- 1 INDICATIONS AND USAGE Regadenoson injection is a pharmacologic stress agent indicated for radionuclide myocardial perfusion imaging (MPI) in patients unable to undergo adequate exercise stress. Regadenoson injection is a pharmacologic stress agent indicated for radionuclide myocardial perfusion imaging (MPI) in patients unable to undergo adequate exercise stress (1) .
Common Doses
- 5 mL
- 0.4 mg
Dosage
2 DOSAGE AND ADMINISTRATION The recommended dose of regadenoson injection is 5 mL (0.4 mg regadenoson) administered as an intravenous injection within 10 seconds. · Patients should be instructed to avoid consumption of any products containing methylxanthines, including caffeinated coffee, tea or other caffeinated beverages, caffeine-containing drug products, aminophylline and theophylline for at least 12 hours before a scheduled radionuclide MPI [see Drug Interactions ( 7.1) and Clinical Pharmacology ( 12.
Contraindications
- 4 CONTRAINDICATIONS Do not administer regadenoson injection to patients with: Second- or third-degree AV block, or sinus node dysfunction unless these patients have a functioning artificial pacemaker [see Warnings and Precautions ( 5.2) ]. Do not administer regadenoson injection to patients with: · Second- or third-degree AV block, or · sinus node dysfunction unless the patients have a functioning artificial pacemaker (4) .
Side Effects
- 6 ADVERSE REACTIONS The following adverse reactions are discussed in more detail in other sections of the labeling. Myocardial Ischemia [see Warnings and Precautions ( 5.1 ) ] Sinoatrial and Atrioventricular Nodal Block [see Warnings and Precautions ( 5.2 ) ] Atrial Fibrillation/Atrial Flutter [see Warnings and Precautions ( 5.3 ) ] Hypersensitivity, Including Anaphylaxis [see Warnings and Precautions ( 5.4 ) ] Hypotension [see Warnings and Precautions ( 5.5 ) ] Hypertension [see Warnings and Precautions ( 5.6 ) ] Bronchoconstriction [see Warnings and Precautions ( 5.
Interactions
- 7 DRUG INTERACTIONS No formal pharmacokinetic drug interacion studies have been conducted with regadenoson. Methylxanthines, e.g., caffeine, aminophylline and theophylline, interfere with the activity of regadenoson injection (7.1, 12.2 ). Aminophylline may be used to attenuate severe and/or persistent adverse reactions to regadenoson injection (7.1, 10) . Dipyridamole may increase the activity of regadenoson injection. When possible, withhold dipyridamole for at least two days prior to regadenoson injection administration (7.1) . 7.1 Effects of Other Drugs on Regadenoson • Methylxanthines (e.