skip to main content

Renal tubular acidosis type 1 — ABIM Board MCQ

Instant feedback + full explanation. One question, done properly.

HardNephrologyRenal tubular acidosis type 1ABIM Board

A patient has recurrent calcium-phosphate stones, potassium 3.0 mEq/L, bicarbonate 16 mEq/L, urine pH 6.4 and a positive urine anion gap during systemic acidosis. Which long-term therapy best addresses the underlying disorder?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: D — Give potassium citrate with dose titration to correct acidosis and hypocitraturia

The best answer is “Give potassium citrate with dose titration to correct acidosis and hypocitraturia”. The findings indicate distal RTA: failure to acidify urine despite systemic acidosis, low ammonium excretion reflected by a positive urine anion gap, hypokalemia and calcium-phosphate stones. Potassium citrate supplies alkali, corrects potassium and raises urinary citrate. Acetazolamide worsens acidosis, while fludrocortisone targets a different hyperkalemic physiology.

Reference: Renal Tubular Acidosis and Management Strategies: https://pmc.ncbi.nlm.nih.gov/articles/PMC7889554/