Effects of Recombinant Urate Oxidase (Rasburicase) and Allopurinol for Prophylaxis and Treatment of Hyperuricemia in Patients with Leukemia and Lymphoma

Efficacy of rasburicase in pediatric patients with leukemia and lymphoma is proved. This study aims to weigh efficacy and safety of rasburicase versus more conventional therapy, allopurinol, and to compare their safety and properties in tumor lysis syndrome (TLS) of leukemia and lymphoma patients. The study was done with a retrospective cohort design. Patients were selected from our hematology ward admitted from 2005 through 2008. Patients were put into two groups based on their blood levels of uric acid, before initiation of chemotherapy; treatment group (the Uric Acid level of 6.5 mg/dl or more) and the prophylaxis group (the uric acid level below 6.5 mg/dl). Evaluation of effectiveness of therapy was performed after 24, 48, 72-hour, and longer periods. Of 184 patients; 69% had leukemia, and 31% lymphoma. Twenty patients were treated with rasburicase and 164 with allopurinol. Mean age of patients was 7.93± 4.247 years old. 60.8% were male and 39.2% were female.According to Chi-square test results, there was no significant difference between two agents regarding prophylaxis (chi-square = 4.247, p-value = 0.193) and treatment (chi-square = 0.780, p-value = 0.677). Most of the response to each agent was seen in the first 24 hours after drug administration. Mean level of uric acid reduced from 7.4 to 3.4mg/dl in rasburicase, and from 5.4 to 3.9 mg/dl in allopurinol group. Mean duration of treatment for rasburicase was 2 days, and for allopurinol 6 days. Adverse effects were minimal in both groups (in rasburicase 1.6% and in allopurinol 5.4%). Rasburicase seems to be highly efficient in both prophylaxis and treatment of Hyperuricemia. Due to high costs in our practice, it was only administered to 20 patients with high levels of blood uric acid or leukocytosis. It prepares patients for chemotherapy faster and decreases cost of hospital stay indirectly by lowering cost of treatment. Allopurinol, alternatively showed equal efficiency and comparable results. Thus, it can be used safely and effectively until rasburicase becomes more widely available and more cost-effective.