Efficacy of a Reduced-dose Rasburicase: Single-institution Experience in India

Abstract Background: Tumor lysis syndrome (TLS) is an oncological emergency associated with life-threatening metabolic abnormalities. Hyperuricemia is a feature of TLS and is treated with hydration, urine alkalinization, and allopurinol. Rasburicase lowers uric acid (UA) rapidly at the labeled dose of 0.15–0.2 mg/kg/day for 5 days. In a developing country like India where affordability is one major limitation to medical care, the use of rasburicase at the dose recommended by the US Food and Drug Administration (FDA) is not always possible. There is no convincing data suggesting the efficacy of a lower dose of rasburicase (1.5 mg or 3 mg) in the treatment of TLS. We conducted a retrospective study from January 2015 to June 2016 to assess the efficacy of a reduced-dose rasburicase in patients with TLS. Materials and Methods: All the patients with TLS were given rasburicase (single dose of 1.5 mg) on day 1 of chemotherapy. Serum UA, potassium, creatinine, and calcium levels were monitored every 24 h. All the patients who did not achieve normalization of UA with one dose of rasburicase were given another 1.5 mg of rasburicase. Results: Out of 90 patients, 54 patients (60%) had normalization of UA levels after 1.5 mg of rasburicase and 16 (18%) patients required 3 mg of rasburicase for bringing down the UA level to normal. The low serum UA levels were maintained even on the 3rd day of rasburicase. Rasburicase was well tolerated, and there was no death due to TLS. Thirty-one patients (64%) had normalization in the serum creatinine levels after rasburicase. Conclusion: We conclude that a low dose of rasburicase (1.5 mg or 3 mg) is cost effective in reducing serum UA (especially for low-risk and intermediate-risk TLS) and the higher dose as recommended by the US FDA is required only for patients with high-risk TLS.