Rasburicase: potential role in managing tumor lysis in patients with hematological malignancies.

Acute tumor lysis syndrome with hyperuricemia and renal failure usually occurs during the initial period of chemotherapy in patients with aggressive hematological malignancies. Standard therapy for hyperuricemia includes hydration, urine alkalinization and pharmacoreduction of uric acid with allopurinol. In the USA, rasburicase has recently been approved by the US Food and Drug Administration for the reduction of uric acid. Rasburicase is a recombinant urate oxidase enzyme that converts uric acid to allantoin, which has increased urine solubility. It is administered intravenously once-daily and leads to rapid, dramatic declines in serum uric acid values. The toxicity profile is excellent, with rare incidence of bronchospasm and allergies and a known contraindication for patients with glucose-6-phosphate dehydrogenase deficiency. A Phase III trial in high-risk pediatric patients conclusively demonstrated that rasburicase is more effective than allopurinol in controlling uric acid. Ongoing evidence is accumulating suggesting that the drug is also safe and effective in adults with hematological malignancies.