A 62-year-old man with acute lymphoblastic leukaemia started on induction chemotherapy develops oliguria 48 hours later. Potassium is 6.8 mmol/L, uric acid 14 mg/dL, phosphate 8.2 mg/dL, calcium 6.9 mg/dL, and creatinine has risen from 0.9 to 3.4 mg/dL. Which agent directly addresses the primary biochemical driver of the renal injury?

• A Allopurinol
• B Rasburicase ✓
• C Calcium gluconate infusion
• D Sodium polystyrene sulfonate

Explanation

Tumour lysis syndrome causes acute uric acid nephropathy: massive nucleic acid breakdown raises uric acid, which precipitates in the acidic tubular environment and obstructs tubules. Rasburicase is a recombinant urate oxidase that converts uric acid to the soluble allantoin, directly removing the offending solute. Allopurinol only prevents new urate formation by xanthine oxidase inhibition and does not lower the already elevated load, so it is inadequate once severe hyperuricaemia with renal failure is established.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.