Last updated on RxList: 9/17/2020
Elitek Side Effects Center

What Is Elitek?

Elitek (rasburicase) is a recombinant urate-oxidase used to treat increased levels of uric acid caused by the breakdown of tumors during treatment for some types of cancer. Elitek increases the rate at which uric acid is broken down in the body.

What Are Side Effects of Elitek?

Common side effects of Elitek include:

  • vomiting,
  • nausea,
  • headache,
  • stomach pain,
  • constipation,
  • diarrhea,
  • anxiety,
  • fever,
  • sore throat,
  • mouth sores or ulcers,
  • swelling in your hands or feet, or
  • rash.

Tell your doctor if you have unlikely but serious side effects of Elitek including:

  • persistent sore throat,
  • fever,
  • chills,
  • chest pain,
  • trouble breathing,
  • severe dizziness,
  • weakness,
  • yellowing eyes and skin,
  • dark urine, or
  • blue or gray skin color.

Dosage for Elitek?

The recommended dose of Elitek is 0.2 mg/kg as a 30-minute intravenous infusion daily for up to 5 days. Other drugs may interact with Elitek. Tell your doctor all prescription or over-the-counter medicines or supplements you use.

What Drugs, Substances, or Supplements Interact with Elitek?

You may require a dosage adjustment or special monitoring if you are taking other medications.

Elitek During Pregnancy and Breastfeeding

Elitek should be used only when prescribed during pregnancy. It is unknown if this drug passes into breast milk. Breastfeeding is not recommended while using this drug.

Additional Information

Our Elitek (rasburicase) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Elitek Consumer Information

Get emergency medical help if you have signs of an allergic reaction: hives, rash; wheezing, chest pain and tightness, difficult breathing; feeling light-headed; swelling of your face, lips, tongue, or throat.

Tell your caregivers or call your doctor at once if you have:

  • pale or yellowed skin, dark colored urine;
  • sores or white patches in or around your mouth, trouble swallowing or talking, dry mouth, bad breath, altered sense of taste;
  • fever, flu symptoms, rapid heart rate, rapid and shallow breathing, fainting; or
  • signs of a serious blood disorder--blue-colored skin or lips, headache, feeling weak or tired, trouble breathing, feeling like you might pass out, pounding heartbeats or fluttering in your chest.

Your treatment with rasburicase may be permanently discontinued if you have a serious allergic reaction.

Common side effects may include:

  • nausea, vomiting, stomach pain;
  • diarrhea, constipation;
  • anxiety;
  • headache;
  • abnormal liver function tests, decreased phosphate levels;
  • throat pain;
  • fever; or
  • swelling in your hands or feet.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Elitek (Rasburicase)

Elitek Professional Information


The following clinically significant adverse reactions are discussed in greater detail in other sections of the prescribing information:


Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The data below reflect exposure to Elitek in 265 pediatric and 82 adult patients enrolled in one active-controlled trial (Study 1), two uncontrolled trials (Studies 2 and 3), and an uncontrolled safety trial (n=82). Additional data were obtained from an expanded access program of 356 patients, for whom data collection was limited to serious adverse reactions. Among these 703 patients 63% were male, the median age was 10 years (range 10 days to 88 years), 73% were Caucasian, 9% African, 4% Asian, and 14% other/unknown.

Among the 347 patients for whom all adverse reactions regardless of severity were assessed, the most frequently observed adverse reactions (incidence ≥10%) were vomiting (50%), fever (46%), nausea (27%), headache (26%), abdominal pain (20%), constipation (20%), diarrhea (20%), mucositis (15%), and rash (13%). In Study 1, an active control study, the following adverse reactions occurred more frequently in Elitek-treated subjects than allopurinol-treated subjects: vomiting, fever, nausea, diarrhea, and headache. Although the incidence of rash was similar in the two arms, severe rash was reported only in one Elitek-treated patient.

Further studies, including one-active controlled study (Study 4) and four supportive studies, have been conducted in adult patients. In these studies, Elitek was administered to a total of 434 adult patients (58% male, 42% female; median age 56 years [range 18 years to 89 years]; 52% Caucasian, 7% African, 14% Asian, 28% other/unknown).

Of these 434 patients, 275 adult patients with leukemia, lymphoma, or solid tumor malignancies at risk for hyperuricemia and tumor lysis syndrome (TLS) were randomized in an open label trial receiving either Elitek alone, Elitek in combination with allopurinol, or allopurinol alone (Study 4).

A drug-related adverse reaction in Study 4 of any grade was experienced in 4.3% of Elitek-treated patients, 5.4% of Elitek/allopurinol-treated patients, and 1.1% of allopurinol-treated patients.

Table 1 presents the per-patient incidence of adverse reactions by study arm in Study 4.

Table 1: Per-Patient Incidence of Selected Adverse Reactions by Study Arm in Study 4

Adverse Reaction*Elitek
Elitek/ Allopurinol
All Grades
All Grades
All Grades
Peripheral edema502.243.53.342.96.6
Abdominal pain21.73.333.74.325.32.2
Pharyngolaryngeal pain14.11.120.709.90
Fluid overload1206.503.31.1
Increased alanine aminotransferase10.93.327.24.317.62.2
Overall incidence ≥10% in any Elitek arm and the difference between any Elitek arm versus the allopurinol arm ≥5%.
* Events were reported and graded according to NCI-CTC version 3.0 and presented as preferred terms MedDRA version 10.1.

Hypersensitivity reactions occurred in 4.3% of Elitek-treated patients and 1.1% of Elitek/allopurinol-treated patients in Study 4. Clinical manifestations of hypersensitivity included arthralgia, injection site irritation, peripheral edema, and rash.

The following serious adverse reactions occurred at a difference in incidence of ≥2% in patients receiving Elitek compared to patients receiving allopurinol in randomized studies (Study 1 and Study 4): pulmonary hemorrhage, respiratory failure, supraventricular arrhythmias, ischemic coronary artery disorders, and abdominal and gastrointestinal infections.

The incidence of anaphylaxis, hemolysis, and methemoglobinemia was less than 1% of the 887 Elitek-treated patients entered on these clinical trials.


As with all therapeutic proteins, there is potential for immunogenicity. Elitek can elicit antiproduct antibodies that bind to rasburicase and in some instances inhibit the activity of rasburicase in vitro [see BOXED WARNING, WARNINGS AND PRECAUTIONS].

In clinical trials of pediatric patients with hematologic malignancies, 24/218 patients tested (11%) developed antibodies by day 28 following Elitek administration as assessed by qualitative ELISA.

Using quasi-quantitative immunoassays in rasburicase-naive adult patients with hematological malignancies, 47/260 (18%) patients were positive for anti-rasburicase immunoglobulin G (IgG), 21/260 (8%) patients were positive for anti-rasburicase neutralizing IgG, and 16/260 (6%) patients were positive for anti-rasburicase immunoglobulin E (IgE) from day 14 to 24 months after 5 daily doses of Elitek.

The incidence of antibody responses detected is highly dependent on the sensitivity and specificity of the assay, which have not been fully evaluated. Additionally, the observed incidence of antibody positivity in an assay may be influenced by several factors, including serum sampling, timing and methodology, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies to Elitek with the incidence of antibodies to other products may be misleading.

Postmarketing Experience

Events were reported and graded according to NCI-CTC version 3.0 and presented as preferred terms MedDRA version 10.1. The following adverse reactions have been identified from clinical trials and/or postmarketing surveillance. Because they are reported from a population of unknown size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Central nervous system disorders: convulsion, muscle contractions involuntary

Immune system disorders: cases of anaphylaxis with fatal outcome have been reported.

Read the entire FDA prescribing information for Elitek (Rasburicase)

© Elitek Patient Information is supplied by Cerner Multum, Inc. and Elitek Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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