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 G protein-coupled receptors with adenosine as the endogenous ligand. There are four known types of adenosine receptors in humans: A1, A2A, A2B and A3; each is encoded by a di ...

agonist An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...

that is a coronary

vasodilator Vasodilation 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. The process is the opposite of vasoconstriction, ...

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. Clinically, ...

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), h ...

. 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 building ...

, 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 respon ...

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 . On February 5, 2020, the company announced management changes effective from April 1, 2020. Astellas is a member of the Mitsubishi UFJ Finan ...

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

European Union The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been des ...

and under the name of Rapiscan. It is marketed by

GE Healthcare GE HealthCare is a subsidiary of American multinational conglomerate General Electric incorporated in New York and headquartered in Chicago, Illinois. As of 2017, it is a manufacturer and distributor of diagnostic imaging agents and radiopharma ...

and is sold in both the United Kingdom and Germany. Regadenoson was approved for use in the European Union in September 2010. Regadenoson has a two- to three-minute

biological half-life Biological half-life (also known as elimination half-life, pharmacologic half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration ( Cmax) to half of Cmax in the bl ...

, 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 cardiac arrhythmia, abnormal heart rhythms, and to protect the heart from a second myocardial infarction, heart attack after a first heart ...

, 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 beta ...

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 prevents solutes in the circulating blood from ''non-selectively'' crossing into the extracellular fluid of ...

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

External links

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