Angiotensin II receptor antagonists, also known as angiotensin receptor blockers (ARBs), AT1-receptor antagonists or sartans, are a group of pharmaceuticals which modulate the renin-angiotensin-aldosterone system. These substances are AT1-receptor antagonists - that is, they block the activation of angiotensin II AT1 receptors.Blockade of AT1 receptors directly causes vasodilation, reduces secretion of vasopressin, reduces production and secretion of aldosterone, amongst other actions - the combined effect of which is reduction of blood pressure. Irbesartan molecule has pyrazolidinone...