Question

What is the site of action of the diuretic thiazide diuretics?

(a) Proximal tubule

(b) Glomerulus

(c) Descending loop of Henle

(d) Distal tubule

I had been asked this question in an interview for internship.

I need to ask this question from Diuretics in section Applications of Pharmacokinetic Principles, Diuretics, Drug Concentration and Pharmacologic Response of Drug Biotechnology

Answer 1

Correct answer is (d) Distal tubule

To explain: Thiazide and thiazide-like diuretics work by inhibiting tubular resorption of sodium and chloride ions. The action primarily in the ascending loop of Henle and early distal tubule. This results in water, sodium, and chloride are excreted. Potassium is also excreted to a lesser extent and dilate the arterioles by direct relaxation, lowers peripheral vascular resistance.