Rasburicase (Elitek)

Indications

Tumor Lysis Syndrome (see Tumor Lysis Syndrome, [[Tumor Lysis Syndrome]]): used for cases where uric acid cannot be lowered by other therapies

Contraindications

Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency (see Glucose-6-Phosphate Dehydrogenase Deficiency, [[Glucose-6-Phosphate Dehydrogenase Deficiency]]): as these patients will be unable to break down the hydrogen peroxide end product of the urate oxidase reaction

Pharmacology

Recombinant Urate Oxidase: catalyzes conversion of uric acid to allantoin (which is soluble)
- Decreases uric acid within hours

Administration

IV: 0.2 mg/kg/day

Adverse Effects

Cardiovascular Adverse Effects

Hypotension (see Hypotension, [[Hypotension]])

Hematologic Adverse Effects

Possible Risk of Hemolysis in Patient with Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency (see Glucose-6-Phosphate Dehydrogenase Deficiency, [[Glucose-6-Phosphate Dehydrogenase Deficiency]] and Hemolytic Anemia, [[Hemolytic Anemia]])

Pulmonary Adverse Effects

Bronchospasm (see Obstructive Lung Disease, [[Obstructive Lung Disease]])
Hypoxemia (see Hypoxemia, [[Hypoxemia]])

Toxicologic Adverse Effects

Methemoglobinemia (see Methemoglobinemia, [[Methemoglobinemia]])
- Patients with low inherited or acquired catalase activity may be at risk for methemoglobinemia after rasburicase administration: due to the formation of hydrogen peroxide
- Some authors recommend the measurement of catalase activity before administering rasburicase

References

Methemoglobinemia and hemolytic anemia after rasburicase administration in a child with leukemia. Int J Clin Pharm. 2011 Feb;33(1):58-60. doi: 10.1007/s11096-011-9484-3. Epub 2011 Feb 4 [MEDLINE]