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Elitek can cause serious and fatal hypersensitivity reactions including anaphylaxis. In clinical studies, anaphylaxis was reported in < 1% patients receiving Elitek. This can occur at any time
during treatment including the first dose. Signs and symptoms of these reactions include bronchospasm, chest pain and tightness, dyspnea, hypoxia, hypotension, shock, and urticaria. Immediately and permanently discontinue Elitek administration in any patient developing clinical evidence of a serious hypersensitivity reaction [see BOXED WARNING, CONTRAINDICATIONS, ADVERSE REACTIONS].
The safety and efficacy of Elitek have been established only for a single course of treatment once daily for 5 days.
Elitek is contraindicated in patients with G6PD deficiency because hydrogen peroxide is one of the major by-products of the conversion of uric acid to allantoin. In clinical studies, hemolysis occurs in < 1% patients receiving Elitek; severe hemolytic reactions occurred within 2-4 days of the start of Elitek. Immediately and permanently discontinue Elitek administration in any patient developing hemolysis. Institute appropriate patient monitoring and support measures (e.g., transfusion support). Screen patients at higher risk for G6PD deficiency (e.g., patients of African or Mediterranean ancestry) prior to starting Elitek [see BOXED WARNING, CONTRAINDICATIONS].
In clinical studies, methemoglobinemia occurred in < 1% patients receiving Elitek. These included cases of serious hypoxemia requiring intervention with medical support measures. It is not known whether patients with deficiency of cytochrome b5 reductase (formerly known as methemoglobin reductase) or of other enzymes with antioxidant activity are at increased risk for methemoglobinemia or hemolytic anemia. Immediately and permanently discontinue Elitek administration in any patient identified as having developed methemoglobinemia. Institute appropriate monitoring and support measures (e.g., transfusion support, methylene-blue administration) [see BOXED WARNING, CONTRAINDICATIONS].
Laboratory Test Interference
At room temperature, Elitek causes enzymatic degradation of the uric acid in blood/plasma/serum samples potentially resulting in spuriously low plasma uric acid assay readings. Special sample handling procedure must be followed to avoid ex vivo uric acid degradation [see BOXED WARNING, DRUG INTERACTIONS].
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Carcinogenicity studies in animals to evaluate tumoriogenic potential of rasburicase have not been performed. Rasburicase was not mutagenic in the Ames, unscheduled DNA synthesis, chromosome analysis, mouse lymphoma, and micronucleus tests.
Rasburicase did not affect reproductive performance or fertility in male or female rats at a dose 50-fold higher (10 mg/kg) than the recommended human dose.
Use In Specific Populations
Pregnancy Category C
There are no studies of rasburicase in pregnant women. Reproductive toxicity studies in rabbits treated during organogenesis with approximately 10 to 100 times the recommended human dose of rasburicase resulted in teratogenicity, including decreased fetal body weights and heart and great vessel malformations at all dose levels. Multiple heart and great vessel malformations were also observed in offspring of pregnant rats treated with approximately 250 times the recommended human dose of rasburicase. Other adverse effects were observed in rasburicasetreated pregnant rabbits at all dose levels tested and included pre-and post-implantation losses, abortions, and decreased uterine weights [see Nonclinical Toxicology].
It is unknown whether rasburicase can cross the placental barrier in humans and result in fetal harm. Because of the observed teratogenic effects of rasburicase in animal reproductive studies, use rasburicase during pregnancy only if the potential benefit to the mother justifies the potential risk to the fetus.
It is not known whether rasburicase is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from rasburicase, a decision should be made whether to discontinue nursing or to discontinue rasburicase, taking into account the importance of the drug to the mother.
The safety and efficacy of Elitek was studied in 246 pediatric patients ranging in age from 1 month to 17 years. There were insufficient numbers of patients between 0 and 6 months (n=7) to determine whether they respond differently from older children. Mean uric acid AUC0-96 hr was higher in children < 2 years of age (n=24; 150 ± s.e. 16 mg hr/dL) than those age 2 to 17 years (n=222; 108 ± s.e. 4 mg hr/dL). Children < 2 years of age had a lower rate of achieving normal uric acid concentration by 48 hours [83% (95% CI: 62, 95)] than those 2 to 17 years [93% (95% CI: 89, 95)].
Of the total number of adults treated with Elitek (n=434) in clinical studies, 30% were aged 65 and over while 8% were aged 75 and over. No overall differences in pharmacokinetics, safety, and effectiveness were observed between the elderly and younger patients.This monograph has been modified to include the generic and brand name in many instances.
Last reviewed on RxList: 6/28/2016
Additional Elitek Information
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