rasburicase

rasburicase,

an antineoplastic antimetabolite used to reduce uric acid levels in children with leukemia or lymphoma and in chemotherapy patients with solid tumor malignancies.

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rasburicase Warning - High-alert drug!

Elitek, Fasturtek (UK)

Pharmacologic class: Recombinant urate oxidase enzyme

Therapeutic class: Antimetabolite

Pregnancy risk category C

FDA Boxed Warning

• Drug may cause severe hypersensitivity reactions (including anaphylaxis), severe hemolysis in patients with G6PD deficiency, and methemoglobinemia. Withdraw immediately and permanently if patient shows evidence of these problems. Before starting therapy, screen patients at higher risk for G6PD deficiency (those of African or Mediterranean ancestry).
• Drug causes spuriously low uric acid levels.

Action

Catalyzes oxidation of uric acid into an inactive soluble metabolite

Availability

Powder for injection: 1.5 mg/vial

⊘Indications and dosages

➣ Chemotherapy-induced hyperuricemia in children with leukemia, lymphoma, or solid-tumor cancers

Children: 0.15 to 0.2 mg/kg by I.V. infusion over 30 minutes as a single daily dose for 5 days. Chemotherapy should begin 4 to 24 hours after first dose.

Off-label uses

• Chemotherapy-induced hyperuricemia in adults with leukemia, lymphoma, or solid-tumor cancers

Contraindications

• Hypersensitivity to drug or its components
• History of anaphylaxis, hemolytic anemia, or methemoglobinemia as a reaction to rasburicase
• G6PD deficiency

Precautions

Use cautiously in:
• pregnant or breastfeeding patients
• children younger than age 2.

Administration

• Know that patients at high risk for G6PD deficiency (those of African or Mediterranean descent) should be screened for this disorder before therapy starts.
• Give 4 to 24 hours before first chemotherapy dose, as ordered.
• Dilute by adding 1-ml vial of diluent provided. Swirl gently; don't shake. Dilute further by injecting diluted dose into infusion bag containing appropriate volume of normal saline solution, to achieve final volume of 50 ml.
• Administer daily by I.V. infusion over 30 minutes.
☞ Don't give as I.V. bolus.
• Don't use I.V. filters.
• Don't mix with other drugs. Use a separate I.V. line, or flush line with 15 ml of normal saline solution before and after infusing rasburicase.
• Know that more than one course of treatment isn't recommended.

Route	Onset	Peak	Duration
I.V.	4 hr	96 hr	Unknown

Adverse reactions

CNS: headache

GI: nausea, vomiting, diarrhea, constipation, abdominal pain

Hematologic: neutropenia, methemoglobinemia, severe hemolysis (in patients with G6PD deficiency)

Respiratory: respiratory distress

Skin: rash

Other: fever, mucositis, hypersensitivity reactions including anaphylaxis, sepsis

Interactions

Drug-diagnostic tests. Neutrophils: decreased count

Uric acid: interference with measurement (if blood is at room temperature)

Patient monitoring

• Monitor for signs and symptoms of hypersensitivity reaction.
• Assess for respiratory distress and signs and symptoms of infection.
• Monitor CBC and uric acid level frequently.
☞ Watch closely for signs and symptoms of hemolysis, especially in patients of African or Mediterranean descent.

Patient teaching

☞ Teach parents and patient (as appropriate) to recognize and immediately report adverse effects, including hypersensitivity reaction.
☞ Tell parents drug may cause sepsis. Instruct them to monitor child's temperature and immediately report fever and other signs and symptoms of infection.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the tests mentioned above.

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rasburicase

Elitek^™ Oncology An agent used in CA Pts with ↑ uric acid due to tumor lysis