Fixed-Dose Rasburicase 6 mg for Hyperuricemia and Tumor Lysis Syndrome in High-Risk Cancer Patients

Tumor lysis syndrome (TLS) is char-acterized by hyperuricemia and oth-er metabolic abnormalities, such as hy-perkalemia, hyperphosphatemia, and hypocalcemia, which occur either spon-taneously with high tumor burden or most commonly following the initiation of cytotoxic therapy.1 Renal failure can result from crystallization of uric acid or precipitation of calcium phosphate ob-structing the renal tubules and collecting system. Laboratory TLS is defined by 2 or more abnormal laboratory values or a 25 % change from baseline (uric acid, potassium, phosphate, or calcium) within 3 days before or 7 days after the initia-tion of treatment.2 Clinical TLS is de-fined as the presence of laboratory TLS and at least 1 of the following events: re-nal failure/insufficiency, need for renal replacement therapy, and/or serum crea-tinine increase>1.5 the upper limit of normal; arrhythmia; or seizure.1 After initial approval in pediatric pa-tients, rasburicase (Elitek, sanofi-aventi