Doses ranged from 2 to 32 mg candesartan cilexetil and from 6.25 to 25 mg hydrochlorothiazide administered once daily in various combinations. In long-term studies of up to one year, the blood pressure lowering effect of the combination was maintained. Angiotensin II is the principal pressor agent of the renin-angiotensin system, with effects that include vasoconstriction, stimulation of synthesis and release of aldosterone, cardiac stimulation, and renal reabsorption of sodium. Candesartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively blocking the binding of angiotensin II to the AT1 receptor in many tissues. Its action is, therefore, independent of the pathways for angiotensin II synthesis.
Hydrochlorothiazide is a thiazide diuretic.
Thiazides affect the renal tubular mechanisms of electrolyte reabsorption, directly increasing excretion of sodium and chloride in approximately equivalent amounts. Indirectly, the diuretic action of hydrochlorothiazide reduces plasma volume, with consequent increases in plasma renin activity, increases in aldosterone secretion, increases in urinary potassium loss, and decreases in serum potassium. Approximately one in every four American adults, and more than half of all Americans over age 65 have high blood pressure. For more information on hypertension and heart-related conditions please visit the web site of the American Heart Association . For more information on Atacand HCT, please visit the web site of AstraZeneca .