Step 1 First Aid Rapid Practice Test

Preventing tumor lysis syndrome centers on keeping uric acid from harming the kidneys by either lowering its production or rapidly removing what’s already present. Allopurinol works by inhibiting xanthine oxidase, so less uric acid is formed from purines. This helps prevent uric acid buildup in patients with functioning kidneys and is a standard preventive approach. Rasburicase, on the other hand, rapidly converts existing uric acid into a soluble, easily excreted form, providing quick control of uric acid in high-risk situations or when uric acid is already rising. Together, these options address both the generation and clearance of uric acid. Probenecid is a uricosuric drug that increases uric acid excretion, but it depends on intact renal function. In tumor lysis syndrome, renal function is often compromised, and probenecid isn’t a reliable or preferred prophylactic choice. It’s more limited and not considered the primary strategy for TLS prevention. Dialysis isn’t a preventive measure; it’s used to manage established TLS with renal failure or severe metabolic derangements, not to prevent the syndrome from developing in the first place. So, the recommended approach is to use allopurinol or rasburicase for prevention, with probenecid reserved only when renal function is clearly good, and dialysis reserved for treating established TLS.