REGADENOSON

Absorption

The pharmacokinetic profile of regadenoson is best described by a 3-compartment model. T max, injection = 1 to 3 minutes; Onset of pharmacodynamic response = 1 to 3 minutes; E max 12.3 ng/mL

Toxicity

The most common (incidence ≥ 5%) adverse reactions to regadenoson are dyspnea, headache, flushing, chest discomfort, dizziness, angina pectoris, chest pain, and nausea. MTD (male, supine position): 20 μg/kg; MTD (male, standing position): 10 μg/kg;

Description

Lexiscan ™(regadenoson) is an injectable adenosine A2A receptor agonist for use as a pharmacologic stress agent in myocardial perfusion imaging (MPI) studies in patients unable to undergo adequate exercise induced stress. Regadenoson is the first adenosine A2A receptor agonist shown to be safe and effective as a pharmacologic stress agent in MPI studies. It is delivered as a rapid bolus (approximately 10 seconds) with no dose adjustment required for body weight. The product was developed under a license and collaboration agreement between CV Therapeutics and Astellas, and was launched by Astellas in June of 2008.

Description

Regadenoson is a coronary vasodilator sold under the trade names Lexiscan (Astella Pharma) and Rapiscan (GE Healthcare). It is an adenosine derivative that acts as an A2A?adenosine receptor agonist. Recently, M. S. Bynoe and co-workers showed that adenosine released when regadenoson is injected into mice?temporarily opens the blood–brain barrier?to admit antibodies and polysaccharides.

The Uses of REGADENOSON

Regadenoson is a selective, short-acting adenosine A2A receptor agonist (Ki = 1.1 nM for pig striatum A2A receptor). It increases coronary blood flow 3.4- to 3.8-fold with a half-time to reversal of 1.9-2.6 minutes in open-chest anesthetized pigs. Regadenoson is used to induce hyperemia (increased blood flow), particularly in the context of myocardial perfusion imaging. It has also been found to increase the delivery of compounds to the central nervous system through the blood-brain barrier in animals.

Indications

Diagnostic agent for radionuclide myocardial perfusion imaging (MPI)

Background

Regadenoson is an A2A adenosine receptor agonist that causes coronary vasodilation and used for myocardial perfusion imagining. Manufactured by Astellas and FDA approved April 10, 2008.

What are the applications of Application

Regadenoson is a selective A2A adenosine receptor agonist in myocardial imaging

Pharmacokinetics

Regadenoson rapidly increases coronary blood flow (CBF) which is sustained for a short duration. Mean average peak velocity increased to greater than twice baseline by 30 seconds and decreased to less than twice the baseline level within 10 minutes. Myocardial uptake of the radiopharmaceutical is proportional to (CBF). Regadenoson increases blood flow in normal coronary arteries but not in stenotic (blocked) arteries. The significance of this finding is that stenotic arteries will take up less of the radiopharmaceutical than normal coronary arteries, resulting in a signal that is less intense in these areas.

Metabolism

The metabolism of regadenoson is unknown in humans. The cytochrome P450 enzyme system is not likely to be involved with the metabolism of regadenoson.