Effective treatment and prophylaxis of hyperuricemia and impaired renal function in tumor lysis syndrome with low doses of rasburicase.

BACKGROUND

Tumor lysis syndrome (TLS) is a complication that can cause renal failure by precipitation of uric acid (UA) and phosphate crystals in renal tubules. Rasburicase proved to be effective in rapidly reducing UA levels. Costs of rasburicase average up to 4500 euros. To assess if lower doses of rasburicase are effective, we treated patients with lower doses than recommended.

PATIENTS AND METHODS

Fifty patients received rasburicase for prophylaxis (n = 8) or treatment (n = 42) of TLS. The median age was 67 yr (16-88), 21 were female. The majority of patients (n = 46) had hematologic malignancies (acute leukemia, 14; lymphoma, 26; myeloproliferative/myelodysplastic syndromes, 6) and four had solid tumors. Creatinine levels were increased in 42 patients.

RESULTS

Baseline median UA and creatinine levels were 856.5 micromol/L (339-1659.5 micromol/L) and 192.7 micromol/L (65.4-761.1 micromol/L), respectively. Patients received between one and eight doses of rasburicase, the median total dose was 0.049 mg/kg. UA levels were lowered by 83%. After rasburicase treatment, median serum UA and creatinine levels were 160.6 micromol/L (5.9-779.2 micromol/L) and 111.4 micromol/L (46.9-610 micromol/L), respectively. Treatment costs were reduced by 96.8%.

CONCLUSIONS

Low doses of rasburicase are effective and cost-saving for prophylaxis and treatment of TLS. Application of an initial dose of 3-4.5 mg of rasburicase and subsequently dosage as needed, depending on UA levels, is feasible.