Dosing and uses of Elitek (rasburicase)
Adult dosage forms and strengths
injection, powder for reconstitution
- 1.5mg/vial
- 7.5 mg/vial
Hyperuricemia Caused by Tumor Lysis
Indicated for the initial management of plasma uric acid levels in pediatric and adult patients with leukemia, lymphoma, and solid tumor malignancies who are receiving anticancer therapy expected to result in tumor lysis and subsequent elevation of plasma uric acid
0.2 mg/kg IV infused over 30 minutes qDay for up to 5 days
Dosing Considerations
Limitation of use: indicated only for a single course of treatment
Dosing beyond 5 days or administration of more than 1 course is not recommended
Pediatric dosage forms and strengths
injection, powder for reconstitution
- 1.5mg/vial
- 7.5 mg/vial
Hyperuricemia Caused by Tumor Lysis
Indicated for the initial management of plasma uric acid levels in pediatric and adult patients with leukemia, lymphoma, and solid tumor malignancies who are receiving anticancer therapy expected to result in tumor lysis and subsequent elevation of plasma uric acid
0.2 mg/kg IV infused over 30 min qDay for up to 5 days
Dosing Considerations
Limitation of use: indicated only for a single course of treatment
Dosing beyond 5 days or administration of more than 1 course is not recommended
Elitek (rasburicase) adverse (side) effects
>10%
Vomiting (50%)
Fever (46%)
Nausea (27%)
Headache (26%)
Abd pain (20%)
Constipation (20%)
Diarrhea (20%)
Mucositis (15%)
Rash (13%)
1-10%
Neutropenia (2-4%)
Resp distress (3%)
Hyperphosphatemia (<10%)
Sepsis (3%)
Neutropenic fever (4%)
<1%
Anaphylaxis
Hemolysis
Methemoglobinemia
Severe rash
Denydration
Acute renal failure
Pancytopenia
Myocardial infarction
Cellulitis
Cardiac failure
Hot flashes
Postmarketing results
Central nervous system disorders: Convulsion, muscle contractions involuntary
Anaphylaxis
Warnings
Black box warnings
May cause serious hypersensitivity reactions, including anaphylaxis. Should be immediately and permanently discontinued in any patient developing clinical evidence of a serious hypersensitivity reaction.
When administered to patients with G-6-PD deficiency, this agent can cause severe hemolysis.
Should be immediately and permanently discontinued in any patient developing hemolysis. It is recommended that patients at a higher risk for G-6-PD deficiency (eg, patients of African or Mediterranean ancestry) be screened prior to starting rasburicase.
Rasburicase use has been associated with methemoglobinemia. Should be immediately and permanently discontinued in any patient developing methemoglobinemia.
Rasburicase causes enzymatic degradation of the uric acid within blood samples left at room temperature, resulting in spuriously low uric acid levels. To ensure accurate measurements, blood must be collected into prechilled tubes containing heparin anticoagulant and immediately immersed and maintained in an ice water bath; plasma samples must be assayed within 4 hours of sample collection.
Contraindications
Hypersensitivity
G6PD deficiency
History of hemolysis or methemoglobinemia reactions to rasburicase
Cautions
Screen patients for G6PD deficiency; immediately and permanently discontinue therapy in any patient developing hemolysis; institute appropriate patient monitoring and support measures (e.g., transfusion support)
Patients should receive adequate hydration as part of uric acid management
Safety & efficacy beyond 5 day or >1 course unknown
Efficacy may be reduced with subsequent courses of therapy due to its imonogenic characteristics; can elicit and antibody response
Immediately and permanently discontinue therapy in any patient identified as having developed methemoglobinemia; institute appropriate monitoring and support measures (e.g., transfusion support, methylene-blue administration)
Interferes with serum uric acid measurement unless blood sample chilled immediately and assayed within 4 hr
Discontinue therapy in any patient developing clinical evidence of a serious hypersensitivity reaction
Pregnancy and lactation
Pregnancy category: C
Lactation: not known if excreted in breast milk, discontinue drug or do not nurse
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Elitek (rasburicase)
Mechanism of action
Recombinant urate oxidase; catalyzes the oxidation of uric acid into allantoin, a soluble metabolite of uric acid
Pharmacokinetics
Half-Life, Terminal: 15.7-22.5 hr
Onset: Within 4 hr of initial administration
Vd: 110-127 mL/kg (peds); 75.8-138 mL/kg (adults)
Administration
IV Preparation
Reconstitute with 1.5 mg vial w/ 1mL and 7.5 mg vial w/ 5 mL of supplied diluent
Mix by gently swirling; do not shake or vortex
Discard if discolored
Further dilute dose in NS to a final volume of 50 mL
Reconstituted solution may be refrigerated but administered within 24 hr
IV Administration
Infuse over 30 min
Do not administer bolus
Do not filter during infusion
If not possible to administer through a separate line, IV line should be flushed with at least 15 mL NS prior to and following rasburicase infusion
Initiate chemotherapy 4-24 hr after 1st dose
Discontinue if signs of hypersensitivity, hemolysis, or methemoglobinemia occur
Monitor: Plasma uric acid
Storage
Prior to reconstitution, store drug and diluent at 2-8°C (36-46°F)
Do not freeze; protect from light
