RASBURICASE 
Pronounciation
- (ras-BYOUR-ih-kase)
Trade Name(s)
- Elitek
Prehydration and baseline studies required; see Monitor.
0.2 mg/kg as a single daily dose each day for up to 5 days. Dosing beyond 5 days and/or administration of more than one course of rasburicase is not recommended. Safety and effectiveness of other schedules have not been evaluated. Alternate unlabeled single- and multiple-dose regimens have been used; see literature.
Available in 1.5- and 7.5-mg single-dose vials with manufacturer-supplied diluent (SWFI and Poloxamer 188). Determine the vial size and/or number of vials needed to provide the calculated dose. Reconstitute each 1.5-mg vial with 1 mL of diluent and each 7.5-mg vial with 5 mL of diluent. Final concentration is 1.5 mg/mL. Mix by swirling gently. Do not shake. Withdraw the calculated dose of reconstituted solution and inject into an infusion bag containing the appropriate volume of NS to achieve a final total volume of 50 mL. (For example a 20-kg child would receive a dose of 4 mg [20 kg × 0.2 mg/kg = 4 mg]. Reconstitute 3 vials, each with 1 mL of the diluent provided. Withdraw 2.7 mL of reconstituted solution and add to an infusion bag containing 47.3 mL of NS.)
No filter should be used during reconstitution or infusion of rasburicase.
Refrigerate unopened lyophilized drug product and diluent. Do not freeze; protect from light. Both the reconstituted and diluted product may be stored for 24 hours if refrigerated. Discard any unused product.
Manufacturer states, “Should be infused through a different line than that used for the infusion of other concomitant medications. If use of a separate line is not possible, the line should be flushed with at least 15 mL of NS prior to and after infusion with rasburicase.”
A single dose as an infusion equally distributed over 30 minutes.
Do not administer as a bolus infusion. Do not filter infusion.
A recombinant urate-oxidase enzyme produced by genetic engineering. Catalyzes enzymatic oxidation of uric acid into an inactive and soluble metabolite (allantoin). Onset of action is 4 hours. Mean terminal half-life is similar between pediatric and adult patients and ranges from 15.7 to 22.5 hours.
Initial management of plasma uric acid levels in pediatric and adult patients with leukemia, lymphoma, and solid tumor malignancies who are receiving anticancer therapy that is expected to result in tumor lysis and subsequent elevation of plasma uric acid.
Indicated only for a single course of treatment.
Glucose-6-phosphate dehydrogenase (G6PD) deficiency.
■ History of anaphylaxis or severe hypersensitivity to rasburicase.
■ History of development of hemolytic reactions or methemoglobinemia with rasburicase.
May cause serious and fatal hypersensitivity reactions, including anaphylaxis. Reactions may occur at any time during treatment, including with the first dose; see Monitor and Antidote.
■ Has caused severe hemolytic reactions in patients with G6PD deficiency. It is recommended that patients at higher risk for G6PD deficiency (e.g., patients of African or Mediterranean descent) be screened for G6PD deficiency before starting rasburicase therapy. See Contraindications and Antidote.
■ Methemoglobinemia has been reported. Patients developed serious hypoxemia, requiring intervention. See Antidote.
■ As with all therapeutic proteins, there is the potential for immunogenicity. May elicit antibodies that inhibit the activity of rasburicase.
Monitor serum uric acid levels, electrolytes, and renal function before and during therapy.
■ Patients should be hydrated intravenously according to standard medical practice for the management of plasma uric acid in patients at risk for tumor lysis syndrome (TLS).
■ Observe for signs of TLS (e.g., hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia). If untreated, may develop acute uric acid nephropathy, leading to renal failure.
■ Monitor for S/S of a hypersensitivity reaction (e.g., anaphylaxis, bronchospasm, chest pain and tightness, dyspnea, hypotension, hypoxia, shock, urticaria).
■ Screen patients at risk for hemolysis; see Contraindications and Precautions. Monitor for S/S of hemolysis (e.g., anemia, jaundice with increased indirect bilirubin and LDH, pallor, reduced haptoglobin). In studies, severe hemolytic reactions occurred within 2 to 4 days of the start of therapy.
■ Monitor for S/S of methemoglobinemia (e.g., cyanosis, dyspnea, headache, hypoxemia, lethargy, methemoglobin).
■ Will cause enzymatic degradation of uric acid within blood samples left at room temperature, resulting in falsely low uric acid levels. To ensure accurate measurement, blood must be collected into prechilled tubes containing heparin anticoagulant and immediately immersed and maintained in an ice water bath. Plasma samples must be prepared by centrifugation in a precooled centrifuge (4° C [39° F]). Plasma samples must be analyzed within 4 hours of sample collection.
Report blood in urine, painful urination, or signs of a hypersensitivity reaction promptly.
■ See Maternal/Child.
Based on animal studies, may cause fetal harm. Potential benefits must justify potential risks to fetus.
■ Breastfeeding is not recommended during treatment and for 2 weeks after the last dose.
■ Studied in pediatric patients from 1 month to 17 years of age. Pediatric patients under 2 years of age had a higher mean uric acid AUC and a lower rate of success at achieving normal uric acid concentrations by 48 hours than did older pediatric patients.
No overall differences in pharmacokinetics, safety, and effectiveness were observed between elderly and younger patients.
Studies have not been conducted.
■ Will cause enzymatic degradation of uric acid within blood samples left at room temperature, resulting in falsely low uric acid levels; see Monitor.
The most common adverse reactions are abdominal pain, anxiety, constipation, diarrhea, fever, headache, hypophosphatemia, increased ALT, nausea, peripheral edema, pharyngolaryngeal pain, and vomiting. Serious adverse reactions observed are hemolysis, hypersensitivity reactions (e.g., anaphylaxis, arthralgia, chest pain, dyspnea, hypotension, injection site irritation, peripheral edema, rash, urticaria), methemoglobinemia, and severe rash. Other observed reactions include abdominal and GI infections, acute renal failure, fluid overload, hyperbilirubinemia, hyperphosphatemia, ischemic coronary artery disorders, mucositis, pulmonary hemorrhage, rash, respiratory distress/failure, sepsis, and supraventricular arrhythmias.
Anaphylaxis with potential fatal outcome, convulsions, muscle contractions (involuntary).
Notify physician of all side effects. Should be immediately and permanently discontinued in patients who experience severe hypersensitivity reactions, hemolysis, or methemoglobinemia. Do not rechallenge. Treat anaphylaxis with epinephrine, corticosteroids (e.g., dexamethasone), oxygen, and antihistamines (diphenhydramine). Hemolysis or methemoglobinemia may require transfusion support. Methylene blue may be required for treatment of methemoglobinemia. There is no specific antidote. Resuscitate as indicated.