Olmesartan medoxomil, the medoxomil ester of olmesartan, is novel and oral antagonist of angiotensin II TYPE-1 receptor (AT₁ receptor) with an inhibition constant IC₅₀ of 33 nmol/L. Through oral administration, olmesartan medoxomil is rapidly absorbed by the gastrointestinal tract converting to its active metabolite olmesartan, whose inhibition constant IC₅₀ towards AT₁ receptor is 8 nmol/L. The esterification of olmesartan with medoxomil moiety is just to improve its water solubility (from 4.5% to 28.6%). Olmesartan medoxomil is used for the treatment of hypertension, in which olmesartan dose-dependently reduces the blood pressure through arterial vasodilation and reducing sodium retention.

Reference

HR Brunner. The new oral angiotensin II antagonist olmesartan medoxomil: a concise overview. Journal of Human Hypertension (2002) 16 (Suppl 2), S13-S16

Shailesh T. Prajapati, Hitesh H. Bulchandani, Dashrath M. Patel, Suresh K. Dumaniya and Chhaganbhai N. Patel. Formulation and evaluation of liquisolid compacts for olmesartan medoxomil. Journal of Drug Delivery 2013.