Cardiovascular drugs: thiazides and calcium: practice question

A Pharmacology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Pharmacology · Cardiovascular drugs: thiazides and calcium

Sample item

A 40-year-old man has recurrent calcium oxalate stones, and 24-hour urine shows idiopathic hypercalciuria. Which drug reduces recurrence?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. Hydrochlorothiazide

Thiazides block the Na+/Cl- cotransporter in the distal convoluted tubule, which increases calcium reabsorption there and reduces urinary calcium. They are useful in hypercalciuric stone formers and also useful in osteoporosis, whereas loop diuretics increase calcium excretion. Thiazides can cause hypercalcaemia, hyperuricaemia and hyponatraemia.

Option by option

  • A. Hydrochlorothiazide (correct)

    Correct. Reduced urinary calcium lowers supersaturation and stone recurrence.

  • B. Acetazolamide

    Acetazolamide causes metabolic acidosis and hypocitraturia, which promotes calcium phosphate stones.

  • C. Furosemide

    Loop diuretics inhibit calcium reabsorption in the thick ascending limb and increase calciuria.

  • D. Mannitol

    Mannitol is an osmotic diuretic that does not lower urinary calcium.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

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Questions about this Pharmacology question

What is the answer to this Pharmacology question?

The best answer is A, Hydrochlorothiazide. Thiazides block the Na+/Cl- cotransporter in the distal convoluted tubule, which increases calcium reabsorption there and reduces urinary calcium.

Why is "Acetazolamide" not the answer?

Acetazolamide causes metabolic acidosis and hypocitraturia, which promotes calcium phosphate stones.

Why is "Furosemide" not the answer?

Loop diuretics inhibit calcium reabsorption in the thick ascending limb and increase calciuria.

Why is "Mannitol" not the answer?

Mannitol is an osmotic diuretic that does not lower urinary calcium.

What concept does this question test?

It tests Cardiovascular drugs: thiazides and calcium in Pharmacology. They are useful in hypercalciuric stone formers and also useful in osteoporosis, whereas loop diuretics increase calcium excretion. Thiazides can cause hypercalcaemia, hyperuricaemia and hyponatraemia.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Cardiovascular drugs: thiazides and calcium?

Learn drugs as classes, then the exception in each class that an examiner would pick. Then use the flashcards and the other Pharmacology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.