skip to main content

Drug-Induced AIN — RACP Adult Medicine MCQ

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

ModerateNephrologyDrug-Induced AINRACP Adult Medicine

A 65-year-old man develops acute kidney injury (creatinine rising from 100 to 500 µmol/L) 10 days after commencing omeprazole. He has no rash. Urine shows sterile pyuria and white cell casts. Eosinophiluria is present. Renal biopsy shows interstitial inflammation with eosinophilic infiltrate. What is the diagnosis?

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

Reveal the answer and explanation

Correct answer: C — Acute interstitial nephritis

Drug-induced acute interstitial nephritis (AIN) is the most common cause of AIN, with PPIs being an increasingly recognised cause (after antibiotics and NSAIDs). PPIs are unique in that AIN can occur months after starting therapy. Sterile pyuria, white cell casts, and eosinophiluria (though sensitivity is only ~30%) are suggestive. Renal biopsy is confirmatory. Treatment involves cessation of the offending drug and a short course of corticosteroids (evidence limited but widely used).

Reference: eTG – 2025 – Nephrology; KDIGO – 2024 – AIN Guidelines