Candesartan

• Hypertension
• Heart Failure
• Cardiovascular Protection
• Diabetic Kidney Disease

Candesartan is an angiotensin II receptor blocker (ARB) used for the treatment of hypertension and heart failure. This medication provides effective cardiovascular protection by blocking the renin-angiotensin-aldosterone system at the receptor level, offering an alternative to ACE inhibitors without causing cough.

Mechanism of Action

Candesartan cilexetil is a prodrug that is rapidly converted to the active drug candesartan during absorption from the gastrointestinal tract. Candesartan selectively blocks the binding of angiotensin II to the AT1 receptor found in vascular smooth muscle, adrenal glands, and other tissues. By blocking this receptor, candesartan prevents angiotensin II from causing vasoconstriction, aldosterone secretion, and sodium retention. This results in vasodilation, reduced blood pressure, decreased cardiac preload and afterload, and reduced cardiac remodeling. Unlike ACE inhibitors, ARBs do not affect bradykinin degradation, which is why they do not cause the dry cough associated with ACE inhibitors.

Available Formulations

Candesartan cilexetil is available as oral tablets in 4 mg, 8 mg, 16 mg, and 32 mg strengths. The tablets can be taken with or without food. Generic formulations are widely available. Combination products with hydrochlorothiazide are also available for enhanced blood pressure control.

Medical Uses

Candesartan is FDA-approved for the treatment of hypertension in adults and children 1-17 years of age, and for the treatment of heart failure (NYHA class II-IV) with left ventricular systolic dysfunction (ejection fraction ≤40%) to reduce cardiovascular death and hospitalizations. The CHARM program demonstrated significant reductions in cardiovascular mortality and heart failure hospitalizations. It may be used alone or in combination with other antihypertensive agents.

Dosing Guidelines

For hypertension in adults, the recommended starting dose is 16 mg once daily, which can be increased to 32 mg once daily for greater effect. For heart failure, starting dose is 4 mg once daily, doubled at 2-week intervals as tolerated to a target dose of 32 mg once daily. For pediatric hypertension, doses are weight-based. Volume-depleted patients or those with hepatic impairment should start at 8 mg. The medication can be taken once or twice daily with equivalent total daily doses.

Important Safety Information

Candesartan carries a boxed warning regarding fetal toxicity; use during pregnancy can cause injury and death to the developing fetus. When pregnancy is detected, candesartan should be discontinued immediately. The medication may cause hypotension, especially in volume-depleted patients or those on diuretics. Hyperkalemia may occur, particularly in patients with renal impairment, diabetes, or those taking potassium-sparing diuretics. Renal function should be monitored, especially in patients with renal artery stenosis.

Drug Interactions

Dual blockade of the renin-angiotensin system (combining ARBs with ACE inhibitors or aliskiren) increases risks of hypotension, hyperkalemia, and renal impairment. NSAIDs may reduce the antihypertensive effect and increase renal risks. Lithium levels may increase when combined with candesartan. Potassium-sparing diuretics and potassium supplements increase hyperkalemia risk. No significant interactions occur with hydrochlorothiazide, digoxin, warfarin, or oral contraceptives.

Special Populations

Candesartan is contraindicated during pregnancy and should be discontinued immediately when pregnancy is detected. It is unknown whether candesartan is excreted in human breast milk; breastfeeding is not recommended. Safety and efficacy have been established in pediatric patients aged 1-17 years for hypertension. Elderly patients do not require dose adjustment based on age alone. Patients with moderate hepatic impairment should start at lower doses (8 mg); severe impairment has not been studied. No dose adjustment is needed for mild to moderate renal impairment.