Question

Which of the following is a loop diuretic?

• A. Spironolactone
• B. Furosemide
• C. Hydrochlorothiazide
• D. Acetazolamide

Hint:

Loop diuretics = “Furo for Fluid” — strong action, quick relief in fluid overload.

Answer 1

The Correct Option is B

To determine which of the options is a loop diuretic, we need to understand the classification and action of the drugs listed:

• Spironolactone: This is a potassium-sparing diuretic, not a loop diuretic. It works by blocking aldosterone receptors in the distal nephron.
• Furosemide: This is a loop diuretic. It acts on the ascending limb of the loop of Henle in the kidney, inhibiting the Na-K-2Cl symporter. This action leads to a significant increase in urine production and is used to treat conditions related to fluid overload, such as heart failure and edema.
• Hydrochlorothiazide: This is a thiazide diuretic and works on the distal convoluted tubule. It is primarily used to manage hypertension and does not have the same site of action as loop diuretics.
• Acetazolamide: This drug is a carbonic anhydrase inhibitor, not a loop diuretic. It affects the proximal tubule and is commonly used to treat conditions like glaucoma or altitude sickness.

Based on the descriptions above, the correct answer is Furosemide, as it is the only loop diuretic among the given options.