Saprisartan is an AT1 receptor antagonist. It is based on medications of losartan's prototypical chemical structure. The mode of (functional) AT1 receptor antagonism has been characterized as insurmountable/noncompetitive for saprisartan. It is very likely that slow dissociation kinetics from the AT1 receptor underlie insurmountable antagonism.(10579749) (en)
Saprisartan is a selective, potent, orally active and long-acting nonpeptide Angiotensin II type 1 (AT1) receptor antagonist. Saprisartan blocks the renin-angiotensin-aldosterone system (RAAS) at the level of the AT1 receptor that mediates most, if not all, of the important actions of Ang II. Saprisartan binds reversibly to the AT1 receptors in vascular smooth muscle and the adrenal gland. As angiotensin II is a vasoconstrictor, which also stimulates the synthesis and release of aldosterone, blockage of its effects results in decreases in systemic vascular resistance. AT1 receptor antagonists avoid the nonspecificity of the Ang I converting enzyme (ACE) inhibitors. (en)