What is the mechanism of action of hydrochlorothiazide?

Hydrochlorothiazide is a thiazide diuretic that primarily functions by inhibiting the sodium-chloride symporter in the distal convoluted tubule of the nephron. This action leads to a reduction in the reabsorption of sodium and chloride ions back into the blood, resulting in increased excretion of these electrolytes and water through urine. This diuretic effect helps to lower blood pressure and reduce fluid retention in various conditions.

The mechanism of action is crucial since the decreased reabsorption of sodium and chloride directly contributes to the therapeutic effects of hydrochlorothiazide, such as its ability to manage hypertension and edema. By understanding this mechanism, one can better appreciate how thiazide diuretics function in clinical practice.