skip to main content

Methotrexate renal impairment — SCE Rheumatology MCQ

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

ModerateRheumatological PharmacologyMethotrexate renal impairmentSCE Rheumatology

A 74-year-old woman on methotrexate for RA develops dehydration from gastroenteritis. Creatinine rises from 78 to 168 micromol/L and she has mouth ulcers. FBC shows platelets 92 × 10⁹/L. She has taken her usual methotrexate dose this week. What is the most appropriate management?

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

Reveal the answer and explanation

Correct answer: E — Withhold methotrexate and assess for toxicity

Explanation lettering: E = shown as B · B = shown as E

Withhold methotrexate and assess for toxicity is best because acute kidney injury reduces methotrexate clearance and mucositis/cytopenia suggest toxicity, requiring withholding and urgent assessment. A is less suitable because blood monitoring is essential; C is less suitable because leflunomide adds toxicity and does not address AKI; D is less suitable because dose escalation is unsafe in AKI; E is less suitable because continuing increases toxicity risk. Clinical pearl: intercurrent illness with AKI is a common setting for methotrexate toxicity.

Reference: BSR csDMARD guideline 2025; BNF