Besanta Mechanism of Action

Pharmacology: Pharmacodynamics: Irbesartan is an anti-hypertensive drug, classified as Angiotensin II type 1 (AT 1) receptor antagonist. Angiotensin II is a potent vasoconstrictor, the primary vasoactive hormone of the renin-angiotensin system. Its effects are vasoconstriction, stimulations of synthesis and release of aldosterone and re-absorption of sodium there are important component in the pathophysiology of hypertension. Angiotensin II receptor antagonist block the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively blocking the binding of angiotensin II at the AT₁ receptor in many tissues; for such, vascular smooth muscle and adrenal gland. Irbesartan does not inhibit ACE, the drug does not interfere with response to bradykinins and substance P.
Pharmacokinetics: The bioavailability of Irbesartan is 60-80% after the oral administration; food has no effect in the absorption. The peak plasma concentration of the drug is within 1.5-2 hours and 90% bind to plasma protein. Less than 20% of the drug is converted to inactive metabolites via CYP2C9. The half-life of the drug is 11-15 hours and the the steady concentration is within 3 days after the first dose. The drug is excreted 20% in urine and 80% in feces; while, less than 2% of the dose is excreted in the urine as unchanged form. Irbesartan is not removed by hemodialysis.