Eprosartan mesylate (SKF-108566J) is a nonpeptide angiotensin II receptor antagonist with IC50 of 9.2 and 3.9 nM in rat and human adrenal cortical membranes, respectively. IC50 Value: 9.2 nM(in rat adrenal cortical membranes); 3.9 nM(in human adrenal cortical membranes)Target: Angiotensin Receptor Type-1(AT1)in vitro: Eprosartan mesylate, is one of the highly selective, orally active, non-peptide angiotensin-II-receptor antagonists [1]. In rat and human adrenal cortical membranes, Eprosartan displaced specifically bound [125I]AII with IC50 of 9.2 and 3.9 nM, respectively. Eprosartan also inhibited [125I]AII binding to human liver membranes (IC50 = 1.7 nM) and to rat mesenteric artery membranes (IC50 = 1.5 nM). In rabbit aortic smooth muscle cells, Eprosartan caused a concentration-dependent inhibition of AII-induced increases in intracellular Ca++ levels. In rabbit aortic rings [2].in vivo: Administration of Eprosartan (3-10 mg/kg) intraduodenally or intragastrically to conscious normotensive rats resulted in a dose-dependent inhibition of the pressor response to AII (250 ng/kg, i.v.). At 10 mg/kg, i.d., significant inhibition of the pressor response to AII was observed for 3 hr. In this same rat model, Eprosartan had no effect on base-line pressure or on the pressor response to norepinephrine or vasopressin [2]. Eprosartan is highly effective and safe in lowering blood pressure, notably SBP, in older subjects with mild to moderate hypertension [3]. Treatment with eprosartan in once-daily doses up to 1200 mg alone or in combination with HCTZ was well tolerated, with dizziness and asthenia being the most common side effects [4]. Therapy with eprosartan mesilat was associated with significant hypotensive effect (more evident in patients with high systolic blood pressure), improvement in 24-hour blood pressure profile and quality of life, and lower probability of secondary stroke. Side effects were not observed [5].

References:
[1]. Qian, J.J., et al., Eprosartan mesylate, an angiotensin II receptor antagonist. Acta Crystallogr Sect E Struct Rep Online, 2011. 67(Pt 4): p. o770-1.
[2]. Edwards, R.M., et al., Pharmacological characterization of the nonpeptide angiotensin II receptor antagonist, SK&F 108566. J Pharmacol Exp Ther, 1992. 260(1): p. 175-81.
[3]. Conter, H.S., D.W. McKay, and R.J. Reiz, Eprosartan mesylate effectively reduces systolic and diastolic blood pressure in a Canadian primary care setting. Can J Cardiol, 2004. 20 Suppl C: p. 6C-10C.
[4]. Punzi, H.A. and C.F. Punzi, Once-daily eprosartan mesylate in the treatment of elderly patients with isolated systolic hypertension: data from a 13-week double-blind, placebo-controlled, parallel, multicenter study. J Hum Hypertens, 2004. 18(9): p. 655-61.
[5]. Martynov, M., et al., [Eprosartan mesylate in controlling of blood pressure in patients with ischemic stroke]. Zh Nevrol Psikhiatr Im S S Korsakova, 2002. 102(4): p. 26-30.