Rasburicase in cancer-related hyperuricemia

Tumor lysis syndrome (TLS) is an oncological emergency consisting of several metabolic derangements: hyperuricemia, hyperkalemia, hyperphosphatemia and hypocalcemia. The rupture of tumor cells in cancer patients can be spontaneous or caused by anticancer therapy. Clinical manifestations of TLS include nausea, anorexia, arrhythmias or renal failure. Prevention and treatment measures include aggressive hydration and concomitant antihyperuricemic therapy. Allopurinol has historically been the only available pharmacological option. Rasburicase was subsequently approved for the management of elevated plasma uric acid levels in adults. This recombinant urate oxidase converts uric acid to allantoin, a more soluble byproduct that is safely eliminated by the kidneys. Manufacturer-labeled dosing for rasburicase in the pediatric and adult populations is 0.2 mg/kg as a daily intravenous (i.v.) infusion for up to 5 days. This review summarizes several studies suggesting that flat, single rasburicase dosing regimens may be just as effective as weight-based dosing. The optimal, most cost-effective adult dose and schedule have yet to be determined.