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

Background: Efficacy of rasburicase in pediatric patients with leukemia and lymphoma is proved. This study aims toweigh efficacy and safety of rasburicase versus more conventional therapy, allopurinol, and to compare their safetyand properties in tumor lysis syndrome (TLS) of leukemia and lymphoma patients.Materials and Methods: The study was done with a retrospective cohort design. Patients were selected from ourhematology ward admitted from 2005 through 2008. Patients were put into two groups based on their blood levelsof uric acid, before initiation of chemotherapy treatment group (the Uric Acid level of 6.5 mg/dl or more) and theprophylaxis group (the uric acid level below 6.5 mg/dl). Evaluation of effectiveness of therapy was performed after24, 48, 72-hour, and longer periods.Results: Of 184 patients 69% had leukemia, and 31% lymphoma. Twenty patients were treated with rasburicaseand 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 toeach 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 was2 days, and for allopurinol 6 days. Adverse effects were minimal in both groups (in rasburicase 1.6% and in allopurinol5.4%).Conclusion: Rasburicase seems to be highly efficient in both prophylaxis and treatment of Hyperuricemia. Due tohigh 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 oftreatment. Allopurinol, alternatively showed equal efficiency and comparable results. Thus, it can be used safely andeffectively until rasburicase becomes more widely available and more cost-effective.