COEZIDAY TABLETS 12.5MG 50MG 20SLosartan blocks the vasoconstrictor and aldosterone secreting effects of angiotensin 2 by selectively blocking the binding of angiotensin 2 to the receptor in many tissues, such as vascular smooth muscle and the adrenal gland. Hydrochlorothiazide is a thiazide diuretic (water pill). It reduces the amount of water in the body by increasing the flow of urine, which helps lower the blood pressure.