Approved April 10, 2008

REGADENOSON
(FDA Category 1)

LEXISCAN(TM) (Astellas Pharma US, Inc) is an A(2A) adenosine receptor agonist. It produces coronary vasodilation, causing a rapid increase in coronary blood flow that lasts for a short duration.

DOSING INFORMATION: The recommended dose is 0.4 milligram administered as a rapid (approximately 10 seconds) intravenous injection, followed by an immediate 5 milliliter saline flush. Administer the radionuclide myocardial perfusion imaging agent 10 to 20 seconds after the saline flush.

PHARMACOKINETICS: Following intravenous injection of regadenoson, coronary blood flow is increased to greater than twice the baseline level by 30 seconds and decreased to less than twice the baseline level within 10 minutes. The Tmax is reached within 1 to 4 minutes after injection, and parallels the onset of the pharmacodynamic response. The metabolism of regadenoson in humans is unknown. The average plasma renal clearance is approximately 450 mL/min. Among healthy subjects, 57% of regadenoson is excreted in the urine unchanged (range, 19% to 77%). The terminal half-life is approximately 2 hours.

CAUTIONS: Regadenoson is contraindicated in patients with second- or third-degree atrioventricular block or sinus node dysfunction, without functioning artificial pacemaker. It may induce myocardial ischemia leading to fatal cardiac arrest, life-threatening ventricular arrhythmias, and myocardial infarction. Due to risk of bronchospasm and respiratory compromise, caution is warranted in patients with known or suspected bronchoconstrictive disease, chronic obstructive pulmonary disease, or asthma. Common side effects include chest discomfort, angina or ST segment depression, irregular heart rhythm or conduction abnormalities, headache, dizziness, nausea, dyspnea, and flushing.

FDA APPROVED INDICATIONS: Regadenoson is indicated as a pharmacologic stress agents for radionuclide myocardial perfusion imaging in patients unable to undergo adequate exercise stress.