Optimal dose of a thiazide diuretic

Area of Science:

• Pharmacology
• Cardiovascular Medicine
• Nephrology

Background:

• Essential hypertension is a common condition requiring effective pharmacologic management.
• Diuretics, such as chlorthalidone, are frequently used to treat hypertension.
• Understanding dose-dependent effects is crucial for optimizing treatment and minimizing adverse events.

Purpose of the Study:

• To compare the antihypertensive efficacy of two different daily doses of chlorthalidone (25 mg vs. 100 mg).
• To evaluate the impact of these doses on extracellular volume, plasma renin activity, serum uric acid, and potassium levels.
• To determine the optimal dose of chlorthalidone for managing essential hypertension.

Main Methods:

• A comparative study involving patients with essential hypertension.
• Administration of chlorthalidone at 25 mg/day and 100 mg/day to different patient groups.
• Monitoring of blood pressure, extracellular volume, plasma renin activity, serum uric acid, and serum potassium levels.

Main Results:

• Both 25 mg and 100 mg of chlorthalidone demonstrated similar blood pressure-lowering effects.
• The 100 mg dose resulted in a greater reduction in extracellular volume and a more significant increase in plasma renin activity and serum uric acid.
• Hypokalemia was more frequent with the 100 mg dose, although neither dose led to total body potassium depletion.

Conclusions:

• The 25 mg daily dose of chlorthalidone provides substantial antihypertensive benefits.
• This lower dose is associated with fewer adverse biochemical changes compared to the 100 mg dose.
• 25 mg of chlorthalidone is recommended as the preferred dose for managing essential hypertension due to its favorable efficacy-to-safety profile.