Which TLS management agent rapidly lowers uric acid levels and requires consideration of G6PD deficiency when used?

• A. Rasburicase
• B. Allopurinol
• C. Hydration alone
• D. Colchicine

Answer: (A)

Rapidly lowering uric acid in tumor lysis syndrome is achieved with rasburicase, because it is a recombinant urate oxidase that converts uric acid to allantoin, a highly soluble product that the body can excrete quickly, preventing uric acid nephropathy after rapid cell breakdown. A key safety consideration with this agent is G6PD deficiency; in G6PD-deficient individuals, the oxidative metabolism triggered by rasburicase can cause hemolysis and methemoglobinemia, so G6PD status must be checked before use. Allopurinol reduces uric acid production by inhibiting xanthine oxidase but does not provide the rapid drop seen with rasburicase and is mainly used for prophylaxis in TLS rather than treatment of established hyperuricemia. Hydration helps preserve kidney function and promotes uric acid excretion but does not actively lower existing uric acid quickly. Colchicine is not used to manage TLS uric acid and is instead used for gout and some inflammatory conditions.