Irbesartan
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sheng Shi, M.D. [2]
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Synonyms / Brand Names: AVAPRO®
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Overview
Irbesartan (INN) /ɜːrbəˈsɑːrtən/ is an angiotensin II receptor antagonist used mainly for the treatment of hypertension. Irbesartan was developed by Sanofi Research (now part of sanofi-aventis). It is jointly marketed by sanofi-aventis and Bristol-Myers Squibb under the trade names Aprovel, Karvea, and Avapro.
Category
Angiotensin II receptor antagonists;Sanofi;Bristol-Myers Squibb;Tetrazoles;Biphenyls;Lactams;Spiro compounds;Nitrogen heterocycles;Cardiovascular Drugs
FDA Package Insert
Indications and Usage | Dosage and Administration | Dosage Forms and Strengths | Contraindications | Warnings and Precautions | Adverse Reactions | Drug Interactions | Use in Specific Populations | Overdosage | Description | Clinical Pharmacology | Nonclinical Toxicology | Clinical Studies | How Supplied/Storage and Handling | Patient Counseling Information | Labels and Packages
Mechanism of Action
Angiotensin II is a potent vasoconstrictor formed from angiotensin I in a reaction catalyzed by angiotensin-converting enzyme (ACE, kininase II). Angiotensin II is the principal pressor agent of the renin-angiotensin system (RAS) and also stimulates aldosterone synthesis and secretion by adrenal cortex, cardiac contraction, renal resorption of sodium, activity of the sympathetic nervous system, and smooth muscle cell growth. Irbesartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively binding to the AT1 angiotensin II receptor. There is also an AT2 receptor in many tissues, but it is not involved in cardiovascular homeostasis.
Irbesartan is a specific competitive antagonist of AT1 receptors with a much greater affinity (more than 8500-fold) for the AT1 receptor than for the AT2 receptor and no agonist activity.
Blockade of the AT1 receptor removes the negative feedback of angiotensin II on renin secretion, but the resulting increased plasma renin activity and circulating angiotensin II do not overcome the effects of irbesartan on blood pressure.
Irbesartan does not inhibit ACE or renin or affect other hormone receptors or ion channels known to be involved in the cardiovascular regulation of blood pressure and sodium homeostasis. Because irbesartan does not inhibit ACE, it does not affect the response to bradykinin; whether this has clinical relevance is not known.