It is crucial for patients to understand the precautions of Rasburicase. Only by fully understanding and following these precautions can the effectiveness and safety of the drug be ensured and a good therapeutic effect be achieved.

Precautions for Rasburicase (Fasturtec)

1. Allergic reactions

Rasburicase can cause severe and fatal allergic reactions, including anaphylaxis. Allergic reactions were reported in <1% of patients taking Rasburicase. This may occur at any time during treatment, including the first dose. Signs and symptoms of these reactions include bronchospasm, chest pain and tightness, dyspnea, hypoxia, hypotension, shock, and urticaria.

For any patient with clinical evidence of a severe allergic reaction, Rasburicase should be discontinued immediately and permanently.

2. Hemolysis

Rasburicase is contraindicated in patients with G6PD deficiency because hydrogen peroxide is one of the main byproducts of the conversion of uric acid to allantoin. Within 2-4 days after starting Rasburicase, <1% of patients treated with Rasburicase experienced severe hemolytic reactions. Immediately and permanently discontinue Rasburicase administration in any patient who develops hemolysis. Institute appropriate patient monitoring and supportive measures, such as transfusion support. Screen patients at increased risk for G6PD deficiency, such as those of African or Mediterranean descent, prior to initiating Rasburicase.

3. Methemoglobinemia

In clinical studies, methemoglobinemia occurred in less than 1% of patients treated with Rasburicase. These included cases of severe hypoxemia requiring intervention with medical supportive measures.

It is not known whether patients deficient in cytochrome b5 reductase (formerly methemoglobin reductase) or other enzymes with antioxidant activity are at increased risk for methemoglobinemia or hemolytic anemia. Immediately and permanently discontinue Rasburicase administration in any patient diagnosed with methemoglobinemia and institute appropriate monitoring and supportive measures.

4. Laboratory Test Interference

At room temperature, Rasburicase can cause degradation of uricase in blood, plasma, or serum samples, potentially resulting in falsely low plasma uric acid assay readings. Special sample handling procedures must be followed to avoid in vitro uric acid degradation.