An irreversible antagonist is a type of
antagonist that binds permanently to a
receptor, either by forming a
covalent bond to the active site, or alternatively just by binding so tightly that the rate of dissociation is effectively zero at relevant time scales. This permanently deactivates the receptor and is usually followed by rapid
internalisation and recycling of the non-functional receptor protein. Irreversible
enzyme inhibitor
An enzyme inhibitor is a molecule that binds to an enzyme and blocks its activity. Enzymes are proteins that speed up chemical reactions necessary for life, in which substrate molecules are converted into products. An enzyme facilitates a sp ...
s that act similarly are clinically used and include drugs such as
aspirin
Aspirin, also known as acetylsalicylic acid (ASA), is a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and/or inflammation, and as an antithrombotic. Specific inflammatory conditions which aspirin is used to treat inc ...
,
omeprazole
Omeprazole, sold under the brand names Prilosec and Losec, among others, is a medication used in the treatment of gastroesophageal reflux disease (GERD), peptic ulcer disease, and Zollinger–Ellison syndrome. It is also used to prevent upp ...
and
monoamine oxidase inhibitors.
[Rang and Dale's Pharmacology. (6th edition, 2007). p19. ]
Examples
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Naloxazone
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Phenoxybenzamine
Phenoxybenzamine (marketed under the trade names Dibenzyline and Dibenyline) is a non-selective, irreversible alpha blocker.
Uses
It is used in the treatment of hypertension, and specifically that caused by pheochromocytoma. It has a slower ons ...
See also
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Irreversible agonist
An irreversible agonist is a type of agonist that binds permanently to a receptor in such a manner that the receptor is permanently activated. It is distinct from a mere (reversible) agonist in that the association of an agonist to a receptor is ...
*
Irreversible enzyme inhibitor
References
Receptor antagonists
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