Regadenoson, sold under the brand name Lexiscan among others, is an A_2A

adenosine receptor The adenosine receptors (or P1 receptors) are a class of Purinergic receptor, purinergic G protein-coupled receptors with adenosine as the endogenous ligand (biochemistry), ligand. There are four known types of adenosine receptors in humans: Aden ...

agonist An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an R ...

that is a coronary

vasodilator Vasodilation, also known as vasorelaxation, is the widening of blood vessels. It results from relaxation of smooth muscle cells within the vessel walls, in particular in the large veins, large arteries, and smaller arterioles. Blood vessel wal ...

that is commonly used in pharmacologic stress testing. It produces

hyperemia Hyperaemia (also hyperemia) is the increase of blood flow to different tissues in the body. It can have medical implications but is also a regulatory response, allowing change in blood supply to different tissues through vasodilation (widenin ...

quickly and maintains it for a duration that is useful for radionuclide

myocardial perfusion imaging Myocardial perfusion imaging or scanning (also referred to as MPI or MPS) is a nuclear medicine procedure that illustrates the function of the heart muscle (myocardium). It evaluates many heart conditions, such as coronary artery disease (CAD), ...

. The selective nature of the drug makes it preferable to other stress agents such as

adenosine Adenosine (symbol A) is an organic compound that occurs widely in nature in the form of diverse derivatives. The molecule consists of an adenine attached to a ribose via a β-N9- glycosidic bond. Adenosine is one of the four nucleoside build ...

, which are less selective and therefore cause more side-effects. Regadenoson was approved by the United States

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...

on April 10, 2008, and is marketed by

Astellas Pharma is a Japanese multinational pharmaceutical company, formed on 1 April 2005 from the merger of and . Astellas is a member of the Mitsubishi UFJ Financial Group (MUFJ) keiretsu. History Early foundations Fujisawa Shoten was started in 1894 ...

under the tradename Lexiscan. It is approved for use in the

European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...

and under the name of Rapiscan. It is marketed by GE Healthcare and is sold in both the United Kingdom and Germany. Regadenoson was approved for use in the European Union in September 2010. It is available as a

generic medication A generic drug is a pharmaceutical drug that contains the same chemical substance as a drug that was originally protected by chemical patents. Generic drugs are allowed for sale after the patents on the original drugs expire. Because the active ch ...

. Regadenoson has a two- to three-minute

biological half-life Biological half-life (elimination half-life, pharmacological half-life) is the time taken for concentration of a drug, biological substance (such as a medication) to decrease from its maximum concentration (chemistry), concentration (Cmax (pharm ...

, as compared with

's ten-second half-life. As a result, regadenoson stress protocols use a single bolus, instead of the four- to six-minute continuous infusion that was needed with adenosine. Whereas the adenosine infusion is weight based (140 mcg/kg/minute), regadenoson is administered as a 0.4 mg/5mL preloaded syringe dose that is standard for all weights. Regadenoson stress tests are not affected by the presence of

beta blockers Beta blockers, also spelled β-blockers, are a class of medications that are predominantly used to manage abnormal heart rhythms (arrhythmia), and to protect the heart from a second heart attack after a first heart attack (secondary prevention). ...

, as regadenoson vasodilates via the adenosine pathway without stimulating beta

adrenergic receptor The adrenergic receptors or adrenoceptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) produced by the body, but also many medications like b ...

s. Regadenoson can temporarily disrupt the integrity of the

blood–brain barrier The blood–brain barrier (BBB) is a highly selective semipermeable membrane, semipermeable border of endothelium, endothelial cells that regulates the transfer of solutes and chemicals between the circulatory system and the central nervous system ...

by inhibiting

P-glycoprotein P-glycoprotein 1 (permeability glycoprotein, abbreviated as P-gp or Pgp) also known as multidrug resistance protein 1 (MDR1) or ATP-binding cassette sub-family B member 1 (ABCB1) or cluster of differentiation 243 (CD243) is an important protein ...

function.

References

Vasodilators Purines Pyrazoles Carboxamides Nucleosides Ribosides Adenosine receptor agonists {{cardiovascular-drug-stub