Acetazolamide CA PCT — FRCA Primary MCQ
Instant feedback + full explanation. One question, done properly.
Educational content. Not a substitute for clinical judgement or local policy.
Reveal the answer and explanation
Correct answer: A — Reduced hydrogen-ion secretion and bicarbonate recovery in the proximal tubule
The best answer is “Reduced hydrogen-ion secretion and bicarbonate recovery in the proximal tubule”. Carbonic anhydrase inhibition in the proximal tubule impairs intracellular H+ generation and luminal H+ secretion, reducing reclamation of filtered bicarbonate and causing alkaline urine with metabolic acidosis. NKCC2, NCC and ENaC are targets of loop, thiazide and potassium-sparing diuretics respectively. Acetazolamide does not act principally by reducing GFR.
Reference: RCoA, Primary FRCA syllabus: https://www.rcoa.ac.uk/sites/default/files/documents/2026-01/Primary-FRCA-Syllabus.pdf; Diuretics and the kidney: https://pmc.ncbi.nlm.nih.gov/articles/PMC9125415/