Class: Recombinant uricase enzyme
Mechanism of Action:
- Converts uric acid → allantoin, a more soluble compound
- Rapidly reduces serum uric acid levels, preventing and treating tumor lysis syndrome (TLS)
Indications
- Prevention and treatment of TLS in patients with hematologic malignancies at high risk (e.g., ALL, AML, Burkitt lymphoma)
- High tumor burden and/or rapidly proliferating tumors
Dosing
- 0.2 mg/kg IV once daily for up to 5 days
- Some protocols use a single fixed dose (e.g., 3–6 mg) off-label
- Administer over 30 minutes in NS
- Do not shake vial (protein denaturation risk)
Key Adverse Effects
- Hypersensitivity reactions: rash, anaphylaxis
- Hemolysis and methemoglobinemia in patients with G6PD deficiency (contraindicated)
- Fever, headache, nausea, vomiting
- Rare: antibody development with repeated doses
Monitoring
- Uric acid levels (avoid sending in room temperature tubes – falsely low)
- Renal function, electrolytes, phosphate, calcium, potassium
- Signs of TLS (labs + clinical status)
- Screen for G6PD deficiency before use (especially in at-risk ethnic groups)
Supportive Notes
- Superior to allopurinol for rapid uric acid reduction
- Does not prevent xanthine accumulation (unlike allopurinol)
- Often used in combination with hydration and electrolyte management
- High cost → typically reserved for high-risk TLS
Other Important Information
- Not for chronic hyperuricemia (gout)
- Discontinue if hypersensitivity or hemolytic reaction occurs
- No dose adjustment needed for renal impairment