Candesartan cilexetil is a prescription medication primarily used to manage cardiovascular conditions. It belongs to the class of pharmaceuticals known as Angiotensin II Receptor Blockers (ARBs). This drug addresses systemic issues contributing to heart and circulatory problems. Its use requires medical supervision and is tailored to the individual patient’s health profile.
How Candesartan Cilexetil Works
Candesartan cilexetil functions as a prodrug, meaning it is inactive when swallowed and must be converted into its active form, candesartan, within the body. This transformation occurs rapidly and completely through ester hydrolysis as the drug is absorbed in the gastrointestinal tract. The active candesartan molecule works by targeting the body’s renin-angiotensin-aldosterone system (RAAS), a hormonal pathway that regulates blood pressure and fluid balance.
Candesartan acts as a selective antagonist for the Angiotensin II type 1 (AT1) receptor. Angiotensin II is a potent hormone that normally binds to this receptor, triggering blood vessel constriction and stimulating the release of aldosterone, which promotes sodium and water retention. By competitively blocking the AT1 receptor, candesartan prevents Angiotensin II from initiating these effects.
This inhibition causes the blood vessels to relax and widen (vasodilation), while also reducing the body’s tendency to retain salt and water. The result is a sustained decrease in overall blood pressure and reduced strain on the heart muscle. Candesartan’s tight binding and slow dissociation from the AT1 receptor contribute to its long-lasting, once-daily antihypertensive effect.
Conditions Treated
The primary indication for candesartan cilexetil is the treatment of essential hypertension (chronic high blood pressure with no identifiable cause). Reducing blood pressure lowers the risk of severe cardiovascular events, including fatal and non-fatal strokes and myocardial infarctions.
Candesartan cilexetil is also indicated for managing heart failure in adult patients. It is typically prescribed for individuals with symptoms corresponding to New York Heart Association (NYHA) functional classes II through IV who have left ventricular systolic dysfunction (ejection fraction of 40% or less). Reducing vascular resistance helps the failing heart pump more efficiently, decreasing its workload.
The therapeutic benefit in heart failure patients includes reducing cardiovascular death and the frequency of hospitalizations related to heart failure exacerbations. The medication can be used alone or in combination with other treatments, such as ACE inhibitors, beta-blockers, and diuretics.
Usage and Dosage Instructions
Candesartan cilexetil is administered orally in tablet form, typically taken once daily due to its long duration of action. It can be taken with or without food, as absorption is not significantly affected by meals. Consistency is achieved by taking the dose around the same time each day to maintain steady drug levels.
The dosage must be tailored to the individual patient and the condition being treated, with tablets available up to 32 milligrams. For adult hypertension, a common starting dose is 16 milligrams once daily, with the total daily dose ranging between 8 and 32 milligrams. The prescribing physician adjusts the dose based on the patient’s blood pressure response.
In treating heart failure, the recommended initial dose is lower, typically 4 milligrams once daily, to allow the body to adjust. The dose is then gradually increased (titrated) by doubling the amount at approximately two-week intervals until the target dose of 32 milligrams once daily is reached, provided the patient tolerates the increase. This slow titration minimizes the potential for adverse effects, such as a sudden drop in blood pressure.
The full therapeutic effect on blood pressure is not immediate. Most reduction is present within two weeks, but the maximal effect is generally achieved after about four weeks of consistent treatment. If a dose is missed, patients should take it as soon as they remember, provided it is within 12 hours of the usual time; otherwise, they should skip the missed dose and take the next one as scheduled.
Safety Profile and Warnings
Candesartan cilexetil carries a boxed warning regarding its use during pregnancy, the most serious type of warning issued by the Food and Drug Administration. Drugs acting directly on the renin-angiotensin system can cause injury or death to a developing fetus, particularly during the second and third trimesters. If pregnancy is detected, the medication must be discontinued immediately.
Common adverse effects are generally mild and may include dizziness, headache, or back pain. More serious, though less frequent, side effects require monitoring by a healthcare professional. These include hypotension (excessively low blood pressure) and potential deterioration of kidney function, especially in patients with existing renal issues.
A primary concern is the risk of hyperkalemia (elevated potassium in the blood). Due to this risk, the use of potassium supplements, potassium-containing salt substitutes, or other drugs that increase potassium levels should be approached with caution. Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, can also increase the risk of hyperkalemia and may diminish candesartan’s blood pressure-lowering effect.
The concurrent use of candesartan with lithium can increase lithium concentration in the blood, potentially leading to toxicity. Patients should inform their doctor about all prescription and non-prescription drugs, supplements, and herbal products they are taking to manage potential interactions. Regular blood tests are typically required to monitor kidney function and potassium levels throughout treatment.