General Information

Atacand HCT (candesartan cilexetil-hydrochlorothiazide) has been developed for the treatment of hypertension, and may be helpful when single products are unsuccessful in reducing blood pressure. Atacand HCT consists of two active ingredients: an angiotensin II receptor antagonist and a diuretic hydrochlorothiazide. It works by inhibiting the effects of angiotensin II, which is an agent that causes vasoconstriction and high blood pressure. Additionally, hydrochlorothiazide reduces blood pressure by improving the kidneys' ability to eliminate salt and fluid from the body. Atacand HCT is available in two tablet strengths: 32 mg Atacand-12.5 mg hydrochlorothiazide and 16 mg Atacand-12.5 mg hydrochlorothiazide.

Clinical Results

Five double-blind, placebo-controlled trials evaluated candesartan cilexetil-hydrochlorothiazide. These five trials, of 8 to 12 weeks duration, consisted of 3037 hypertensive patients. Doses ranged from 2 to 32 mg candesartan cilexetil and from 6.25 to 25 mg hydrochlorothiazide administered once daily in various combinations.

The combination of candesartan cilexetil-hydrochlorothiazide resulted in placebo-adjusted decreases in sitting systolic and diastolic blood pressures of 14-18/8-11 mm Hg at doses of 16-12.5 mg and 32-12.5 mg (the two tablet stengths). In long-term studies of up to one year, the blood pressure lowering effect of the combination was maintained.

Side Effects

The most common adverse events observed with Atacand HCT use include the following:

• 
  
• Upper respiratory infection
• Dizziness
• Back pain
• Flu-like symptoms

Atacand HCT should not be used by pregnant women and should be discontinued if pregnancy is detected.

Mechanism of Action

Angiotensin II is formed from angiotensin I in a reaction catalyzed by angiotensin-converting enzyme (ACE). 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. (from FDA Label)

Additional Information

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.