Ambulatory Care Nurse Certification 2025 – 400 Free Practice Questions to Pass the Exam

Thiazide diuretics play a significant role in the management of hypertension and edema by exerting their effects primarily in the distal convoluted tubule of the nephron. Their primary mechanism involves the inhibition of sodium and chloride reabsorption. By blocking the reabsorption of these ions, thiazide diuretics increase the excretion of sodium and water, which helps reduce blood volume and, consequently, blood pressure.

This selective action on sodium and chloride channels is why the correct choice highlights these ions as the substances that thiazide diuretics are specifically known to block. The increased urinary output of sodium and chloride leads to a reduction in fluid retention and can effectively lower blood pressure in patients with hypertension.

The other ion options, such as potassium, magnesium, calcium, bicarbonate, phosphate, and sulfate, are not the primary targets of thiazide diuretics. While thiazides can influence potassium levels indirectly, as they promote the excretion of potassium as a side effect, their main pharmacological action is centered around sodium and chloride reabsorption. Understanding the specific mechanism of action of thiazide diuretics is crucial for their effective and safe use in clinical practice.