What is the use of Chlorthalidone (Thiazide-like Diuretic)?

From the Guidelines

Chlorthalidone is a thiazide-like diuretic medication primarily used to treat high blood pressure and fluid retention, with a recommended dose of 12.5 to 25 mg once daily, as stated in the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 1.

Key Points

• Chlorthalidone works by increasing urine output and reducing sodium reabsorption in the kidneys, which helps lower blood pressure and reduce edema.
• It has a longer duration of action (24-72 hours) compared to other thiazide diuretics like hydrochlorothiazide, allowing for once-daily dosing and providing more consistent blood pressure control.
• Common side effects include electrolyte imbalances (particularly low potassium), increased blood sugar, increased uric acid levels, and increased cholesterol.
• Patients taking chlorthalidone should have their electrolytes monitored periodically, especially potassium levels, as recommended in the guideline 1.
• Chlorthalidone is particularly effective for patients with resistant hypertension and has shown superior cardiovascular outcomes compared to some other diuretics in clinical studies, as noted in the Circulation journal 1.

Important Considerations

• Patients should maintain adequate hydration while taking this medication and report symptoms like severe dizziness, muscle weakness, or irregular heartbeat, which could indicate electrolyte imbalances.
• Chlorthalidone is preferred over other diuretics due to its prolonged half-life and proven trial reduction of cardiovascular disease, as stated in the guideline 1.
• The medication should be taken in the morning to avoid nighttime urination disrupting sleep.
• Combination therapy of potassium-sparing diuretic with a thiazide can be considered in patients with hypokalemia on thiazide monotherapy, but should be avoided in patients with significant chronic kidney disease (CKD), as recommended in the guideline 1.

From the FDA Drug Label

INDICATIONS AND USAGE Diuretics such as chlorthalidone are indicated in the management of hypertension either as the sole therapeutic agent or to enhance the effect of other antihypertensive drugs in the more severe forms of hypertension. Chlorthalidone is indicated as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy Chlorthalidone has also been found useful in edema due to various forms of renal dysfunction, such as nephrotic syndrome, acute glomerulonephritis, and chronic renal failure.

The use of Chlorthalidone (Thiazide-like Diuretic) is for:

• Hypertension management: as a sole therapeutic agent or to enhance the effect of other antihypertensive drugs
• Edema treatment: associated with congestive heart failure, hepatic cirrhosis, corticosteroid and estrogen therapy, and various forms of renal dysfunction, such as nephrotic syndrome, acute glomerulonephritis, and chronic renal failure 2

From the Research

Use of Chlorthalidone

• Chlorthalidone is a thiazide-like diuretic used to treat hypertension 3, 4, 5, 6, 7
• It is recommended as the preferred thiazide diuretic to treat hypertension, but recent studies have shown that it may not be associated with significant cardiovascular benefits when compared with hydrochlorothiazide 3, 7
• Chlorthalidone has been shown to be effective in lowering blood pressure, but its use is also associated with a higher risk of renal and electrolyte abnormalities, such as hypokalemia, hyponatremia, and acute renal failure 3, 6

Comparison with Hydrochlorothiazide

• Chlorthalidone and hydrochlorothiazide are both thiazide diuretics, but they have different pharmacological properties and effects on the body 4, 5, 6
• Some studies have suggested that chlorthalidone may be more effective than hydrochlorothiazide in preventing cardiovascular disease events, but other studies have found no significant difference between the two medications 3, 5, 6, 7
• Chlorthalidone has been associated with a higher risk of side effects, such as hypokalemia and hyperuricemia, compared with hydrochlorothiazide 3, 6

Clinical Considerations

• The choice between chlorthalidone and hydrochlorothiazide as a first-line treatment for hypertension should be based on individual patient characteristics and medical history 6, 7
• Clinicians should carefully consider the potential benefits and risks of each medication and monitor patients closely for adverse effects 3, 6, 7