From the Guidelines
Rasburicase works by catalyzing the oxidation of uric acid to allantoin, a water-soluble compound that is easily excreted by the kidneys. Rasburicase is a recombinant urate oxidase enzyme derived from Aspergillus flavus that provides this enzymatic activity that humans naturally lack. The medication is primarily used to prevent or treat tumor lysis syndrome, a condition where rapid breakdown of cancer cells releases large amounts of uric acid into the bloodstream. Some key points to consider when using rasburicase include:
- The typical dosing of rasburicase is 0.2 mg/kg administered as a single daily intravenous infusion for up to 5 days, though a single dose is often sufficient 1.
- Rasburicase acts immediately upon administration and can reduce serum uric acid levels within hours, making it more effective than allopurinol for acute management of hyperuricemia 1.
- Important considerations include screening patients for G6PD deficiency before administration, as rasburicase can cause severe hemolysis in these individuals 1.
- Additionally, blood samples for uric acid measurement must be collected in pre-chilled tubes and processed immediately to prevent ex vivo degradation of uric acid by the drug 1. Rasburicase has been shown to be effective in reducing uric acid levels and preventing tumor lysis syndrome in both pediatric and adult patients 1. Overall, rasburicase is a valuable tool in the management of tumor lysis syndrome, and its use should be considered in patients at high risk of developing this condition.
From the FDA Drug Label
- 1 Mechanism of Action In humans, uric acid is the final step in the catabolic pathway of purines. Rasburicase catalyzes enzymatic oxidation of poorly soluble uric acid into an inactive and more soluble metabolite (allantoin). The mechanism of action of rasburicase is enzymatic oxidation of uric acid into allantoin, a more soluble and inactive metabolite.
- Rasburicase works by breaking down uric acid in the body.
- This process helps to prevent the buildup of uric acid, which can occur in patients with certain types of cancer who are undergoing chemotherapy 2.
From the Research
Mechanism of Action of Rasburicase
- Rasburicase is a recombinant urate oxidase that converts uric acid into a more water-soluble compound called allantoin, which can be easily excreted by the kidneys 3.
- This enzyme catalyzes the oxidation of hypoxanthine and xanthine to form allantoin, thereby reducing uric acid levels in the body 4.
- The mechanism of action of rasburicase involves the breakdown of uric acid into allantoin, which is then excreted by the kidneys, resulting in a rapid decrease in plasma uric acid levels 5, 6.
Clinical Applications
- Rasburicase is used to prevent and treat hyperuricemia, a condition characterized by elevated levels of uric acid in the blood, which can occur in patients with cancer, particularly those with hematological malignancies 5, 6.
- It is also used to treat tumor lysis syndrome, a condition that occurs when large numbers of cancer cells die rapidly, releasing uric acid and other substances into the bloodstream 4.
- Additionally, rasburicase has been used to treat gout, a condition characterized by elevated levels of uric acid in the blood, which can cause joint pain and inflammation 3, 4.
Efficacy and Safety
- Rasburicase has been shown to be effective in reducing uric acid levels and preventing hyperuricemia in patients with cancer 5, 6.
- It has also been shown to be safe and well-tolerated, with few adverse reactions reported 5, 6, 4.
- However, rasburicase can cause allergic reactions and the development of antibodies, which can compromise its effectiveness 4.