Urapidil
Encyclopedia
Urapidil is a sympatholytic
antihypertensive
drug
. It acts as an α1-adrenoceptor antagonist
and as an 5-HT1A receptor
agonist
Although an initial report suggested that urapidil was also an α2-adrenoceptor agonist
, this was not substantiated in later studies that demonstrated it was devoid of agonist actions in the dog saphenous vein and the guinea-pig ileum. Unlike some other α1-adrenoceptor antagonists
, urapidil does not elicit reflex tachycardia, and this may be related to its weak β1-adrenoceptor antagonist
activity, as well as its effect on cardiac vagal drive Urapidil is currently not approved by the U.S. Food and Drug Administration
, but it is available in Europe
.
Sympatholytic
A sympatholytic drug is a medication which inhibits the postganglionic functioning of the sympathetic nervous system . They are indicated for various functions, for example they may be used as antihypertensives...
antihypertensive
Antihypertensive
The antihypertensives are a class of drugs that are used to treat hypertension . Evidence suggests that reduction of the blood pressure by 5 mmHg can decrease the risk of stroke by 34%, of ischaemic heart disease by 21%, and reduce the likelihood of dementia, heart failure, and mortality from...
drug
Drug
A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage.In pharmacology, a...
. It acts as an α1-adrenoceptor antagonist
Receptor antagonist
A receptor antagonist is a type of receptor ligand or drug that does not provoke a biological response itself upon binding to a receptor, but blocks or dampens agonist-mediated responses...
and as an 5-HT1A receptor
5-HT1A receptor
The 5-HT1A receptor is a subtype of 5-HT receptor that binds the endogenous neurotransmitter serotonin . It is a G protein-coupled receptor that is coupled to Gi/Go and mediates inhibitory neurotransmission...
agonist
Agonist
An agonist is a chemical that binds to a receptor of a cell and triggers a response by that cell. Agonists often mimic the action of a naturally occurring substance...
Although an initial report suggested that urapidil was also an α2-adrenoceptor agonist
Agonist
An agonist is a chemical that binds to a receptor of a cell and triggers a response by that cell. Agonists often mimic the action of a naturally occurring substance...
, this was not substantiated in later studies that demonstrated it was devoid of agonist actions in the dog saphenous vein and the guinea-pig ileum. Unlike some other α1-adrenoceptor antagonists
Receptor antagonist
A receptor antagonist is a type of receptor ligand or drug that does not provoke a biological response itself upon binding to a receptor, but blocks or dampens agonist-mediated responses...
, urapidil does not elicit reflex tachycardia, and this may be related to its weak β1-adrenoceptor antagonist
Receptor antagonist
A receptor antagonist is a type of receptor ligand or drug that does not provoke a biological response itself upon binding to a receptor, but blocks or dampens agonist-mediated responses...
activity, as well as its effect on cardiac vagal drive Urapidil is currently not approved by the U.S. Food and Drug Administration
Food and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
, but it is available in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
.