Single dose rasburicase in tumor lysis: One hospital's experience

Abstract

AbstractBackground: Tumor lysis syndrome is an oncological emergency occurring mainly in high‐grade hematological malignancies. It results in significant biochemical abnormalities including hyperuricemia and acute renal failure. Rasburicase is a recombinant urate oxidase enzyme that catalyzes oxidation of uric acid into allantoin, which is easily excreted in the urine. Reports in the literature suggest that a single dose of rasburicase is effective in treating tumor lysis syndrome, whereas the current dose recommended by the manufacturer is 0.2 mg/kg/day for 5 to 7 days, which is very costly ($13 000 for an average 70‐kg person). We present a retrospective analysis on the patients at our hospital that have received rasburicase as a single dose.Methods: Medical and pharmacy dispensing records were searched to identify patients with high‐grade hematological malignancy who received a single dose of rasburicase in a 12‐month period. Data on renal function, electrolytes, and uric acid were obtained.Results: Twenty‐three patients were newly diagnosed with high‐grade hematological malignancy (Burkitt lymphoma 4, AML 17, APML 1, DLBCL 1). A single dose of rasburicase 0.2 mg/kg was administered to six of these patients considered to be at high risk, five of whom had an elevated uric acid level before treatment. Their uric acid levels were monitored from 24 h to 96 h after this dose. Normal uric acid levels were seen in all patients within 24 h. These levels remained normal for 96 h. One of five patients died of pre‐existing renal failure despite the normalization of their uric acid.Conclusion: We conclude that single dose rasburicase is effective in the treatment of hyperuricemia in patients at risk of tumor lysis and effectively reduces the level of uric acid for up to 96 h. This makes it cost effective and theoretically reduces the risk of hypersensitivity associated with rasburicase.