Rasburicase (Intravenous)

Rasburicase is an intravenous drug that is used to treat high levels of uric acid in the bloodstream that results from tumor lysis syndrome caused by chemotherapy.

Overview

Rasburicase is sold under the brand name Elitek. This is an intravenous drug that is used to lower very high levels of uric acid in the body that result from tumor lysis syndrome. Tumor lysis syndrome occurs in patients with leukemia, lymphoma and solid tumor cancers who are receiving high doses of chemotherapy. When the tumor cells begin to die off in large numbers, metabolic disturbances can occur throughout the body leading to high levels of uric acid, calcium, phosphate and potassium in the bloodstream. When these levels are too great in the body, the kidneys are not able to function properly which may lead to kidney damage. Raburicase will lower the level of uric acid when tumor lysis occurs. It is often used before chemotherapy when tumor lysis syndrome is anticipated.

Raburicase works in the body to change uric acid into an inactive form. The drug oxidizes uric acid and transforms it into allantoin which has a neutral action within the body.

This drug has a number of side effects, and doctors must weigh the benefits of using the drug against any potential side effects. This drug has a black box warning attached for some significant side effects that may cause serious harm to those patients using the drug. The black box warnings also include information on those who should not use the drug. Special screening needs to be completed on patients of African and/or Mediterranean descent before rasburicase is administered.

The drug is only used in intravenous form. It is given in a medical setting, and the infusion process takes approximately two hours. It is a one course treatment, and doctors recommend that subsequent courses not be given.

Treatment with rasburicase is very expensive in relation to drugs which are indicated for the same purpose. As a general rule, patients will only receive this drug if other means are not considered sufficient or appropriate.

Conditions Treated

  • Elevated uric acid due to tumor lysis syndrome.

Type of Medicine

  • Recombitant urate-oxidase enzyme

Side Effects

There are many side effects associated with the use of rasburicase. The most common side effect is vomiting which occurs in approximately half of all patients who use the drug. Roughly 25 percent of patients also report severe nausea after treatment. Abdominal pain, diarrhea, and constipation are also reported in as many as one-fifth of patients using the drug. In some cases, patients may have bloody diarrhea or blood in the stool. Gastrointestinal problems are by far the most common side effects when using rasburicase.

Another common side effect of rasburicase administration is the development of a fever which occurs in slightly less than 50 percent of patients. In addition to the fever, some patients also experience a sensation of heat through the body, and some patients have redness in the face, neck and extremities.

Side effects are common in the mouth and throat. Some patients have developed inflammation of the oral mucous membranes and swelling of the throat. Some have reported difficulty in swallowing while the drug is in their system. Others report cracked lips and white sores that occur on the lips and the tongue. Sore throat has also been reported.

Several types of skin side effects have been reported with this drug's use. The most reported side effect is a generalized skin rash that occurs in about 13 percent of patients. Other skin side effects reported include itching, yellowing of the skin, wrinkled skin and pale skin. Other changes in skin color have been reported.

There are several respiratory type side effects patients have encountered. These side effects include pain in the chest, difficulty in breathing and rapid breathing. Severe respiratory distress has been reported along with patients coughing up blood. Wheezing has also been reported.

Cardiac side effects are known to occur in patients using rasburicase. Patients have experienced rapid and/or decreased heart rhythms as well as irregular heart beats. Dilation of the neck veins may occur. The most serious cardiac side effects reported are in patients who have suffered a myocardial infarction while on the drug and in patients who have had their hearts stop completely while on the drug.

Hematological side effects are known to occur when using rasburicase. Some of these hematological side effects include neutropenia, hyperphosphotemia, hemolysis, pancytopenia and increased bleeding that may result in blood in the urine.

There have been reports of neurological side effects. Some of these include dizziness, seizures, agitation, coma, depression, muscle twitching, paralysis, slurred speech, and unconsciousness.

There are two very serious side effects that have received a black box warning. First of all, rasburicase has caused serious allergic reactions causing patients to experience anaphylaxis. Patients experiencing this type of severe reaction will experience extreme difficulty when breathing. They may go into shock. There have been fatalities reported in patients using this drug who have had severe allergic reactions.

Also, methemoglobinemia has occurred in some patients using rasburicase. If this occurs, the patient should be taken off the drug immediately, and it should not be used in the future.

One additional serious side effect should be noted. Greater than 10 percent of those using rasburicase have developed sepsis after using the drug. These infections were grade three and four infections in most instances.

In addition to the side effects noted for the drug itself, patients have reported side effects at the injection site. Pain, swelling, redness and irritation have all been reported.

Dosage

Rasburicase comes in two forms. There is a 1.5 mg powder in a single dose vial, and there is a 7.5 mg powder that also comes in single dose vial. The powder must be reconstituted for use. If using the 1.5 mg powder, 1 ml of diluent is added for reconstitution. If the 7.5 mg powder is used, 5 ml of diluent is used for reconstitution. This mixture is then placed in an IV bag with 0.9 percent sterile sodium chloride to obtain a 50 ml total volume.

Adult patients should receive 0.2 mg per kg for 30 minutes per day. This should be continued for five days to complete one course of treatment.

Pediatric patients should receive the same dosage as adults for the same period of time.

Interactions

There are six known drug interactions with rasburicase. The drugs known to cause interactions are:

  • Lidocaine
  • Prilocaine
  • Sodium nitrate
  • Sodium thiosulfate
  • Amyl nitrate
  • Idelalisib

Patients should inform their doctors of all the prescription drugs, non-prescription drugs and supplements that they are taking before rasburicase is administered.

Warnings

There are several black box warnings associated with rasburicase. This drug is known to cause severe allergic reactions. While a patient is using this drug he/she should be aware of the signs of an allergic reaction. Any breathing difficulties, rashes, swelling of the face or lips, or a bluish tinge to the fingers or lips should be reported to the physician immediately. The drug should be immediately discontinued if any signs of allergic reaction occur as this drug has allergic fatalities associated with its use.

Rasburicase may cause methemoglobinemia. If this develops or is suspected, the drug should be discontinued.

Patients with glucose-6-phosphate dehydrogenase deficiency should not receive this drug. The use of this drug in patients with this deficiency may lead to hemolysis.

When using rasburicase, the level of uric acid in the body may be measured abnormally low. This results when the blood sample is left at room temperature. At room temperature, rasburicase degrades uric acid in the blood. To counteract this, blood samples must be collected in chilled tubes that contain heparin. The sample tubes must then be placed in an ice bath. The test for uric acid in the blood must be conducted within four hours of the blood draw.

Rasburicase is listed as Pregnancy Category C. It is not known whether or not this drug will cause harm to a fetus. The benefit of using the drug must be weighed against unknown harm to the fetus. It is not known if this drug is excreted in breast milk. Nursing mothers should take precaution if using this drug while breastfeeding.

The side effects associated with rasburicase are often more pronounced in those patients who are of African and/or Mediterranean descent. Those of African and/or Mediterranean descent should be closely monitored for adverse reactions during the course of using this drug.

Storage

This drug needs to be refrigerated. It should be stored between 36 and 46 degrees Fahrenheit. The drug should not be exposed to the light before it is reconstituted. This drug is only used in a medical setting. Patients will not store this drug at home.

Summary

Rasburicase is sold under the name Elitek. It is used in both adult and pediatric patients to lower the level of uric acid in the body when the level of uric acid is elevated due to tumor lysis syndrome. This syndrome occurs in patients being treated with chemotherapy who have leukemia, lymphoma and solid tumor cancers.

Rasburicase is used in intravenous form. It is used each day for a period of five days and only one course of the treatment should be used.

The drug acts in the system by taking uric acid and turning it into a neutral form which causes no harm to the body or any of its organs.

Rasburicase has several serious side effects associated with its use. The drug has a black box warning for several causes. Fatal allergic reactions have occurred in patients using rasburicase. Patients should immediately report any suspected allergic reaction to their physician.

Those of African and/or Mediterranean descent should be carefully monitored while on the drug. Side effects are often more severe in those of African and/or Mediterranean descent.

The majority of the side effects associated with the use of this drug are gastrointestinal in nature. Vomiting is the most reported side effected followed by nausea.

Rasburicase has not been tested in pregnant and nursing mothers, so precaution should be taken when considering this drug.

 

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Last Reviewed:
January 28, 2018
Last Updated:
January 27, 2018
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