American Board of Internal Medicine (ABIM) Certification Practice Exam

What medication is used for the treatment of tumor lysis syndrome in patients with uric acid nephropathy?

1. Allopurinol

2. Rasburicase

3. Probenecid

4. Ursodiol

The correct answer is: Rasburicase

Rasburicase is utilized in the treatment of tumor lysis syndrome, particularly in patients experiencing uric acid nephropathy. Tumor lysis syndrome can occur after the rapid destruction of tumor cells, leading to the release of intracellular components into the bloodstream, including uric acid. Elevated uric acid levels can precipitate acute kidney injury due to uric acid crystallization, which can severely affect renal function. Rasburicase is a recombinant urate oxidase enzyme that catalyzes the conversion of uric acid to allantoin, a more soluble compound that can be easily excreted by the kidneys. This mechanism significantly reduces the levels of uric acid in the blood and prevents the associated complications, particularly in patients with elevated uric acid levels due to tumor lysis syndrome. Allopurinol is another medication used for hyperuricemia; however, it works by inhibiting the enzyme xanthine oxidase, which reduces uric acid production rather than breaking it down. Probenecid facilitates the renal excretion of uric acid but is less effective in acute situations like tumor lysis syndrome. Ursodiol is a medication used primarily to dissolve gallstones and is not relevant in this context. Hence,