rasburicase

Action and Spectrum

Actions and Spectrum:

The action of rasburicase is to convert uric acid into a form that is more water-soluble and easily excreted from the body. This reduces the risk of uric acid crystals forming in the body, which can lead to gout and kidney stones.

The spectrum of rasburicase includes its use in the treatment of hyperuricemia in patients with cancer, particularly those undergoing chemotherapy or radiation therapy. This medication is also used in patients with kidney disease, as well as in patients with inherited metabolic disorders that lead to high levels of uric acid in the blood.

Drug Interaction

Adverse Reaction

Frequency defined

>10%

Nausea (27%)

Fever (46%)

Headache (26%)

Constipation (20%)

Abdominal pain (20%)

Diarrhea (20%)

Vomiting (50%)

Rash (13%)

Mucositis (15%)

1-10%

Respiratory distress (3%)

Neutropenia (2-4%)

Hyperphosphatemia (<10%)

Neutropenic fever (4%)

Sepsis (3%)

<1%

Hemolysis

Anaphylaxis

Methemoglobinemia

Dehydration

Severe rash

Acute renal failure

Myocardial infarction

Pancytopenia

Cellulitis

Hot flashes

Cardiac failure

Black Box Warning

Black Box Warning

The black box warning for rasburicase states that there is a risk of severe allergic reactions, including anaphylaxis, which can be life-threatening. Patients should be monitored closely for signs of allergic reactions, and if they occur, rasburicase should be discontinued immediately.

Contraindication / Caution

Contraindication/Caution:

rasburicase is contraindicated in patients with a known hypersensitivity to rasburicase or any of its excipients. It should be used with caution in patients with glucose-6-phosphate dehydrogenase deficiency, as hemolysis and methemoglobinemia have been reported with the use of rasburicase in these patients.

Additionally, rasburicase should be used with caution in patients with a history of bleeding or with blood clotting disorders. In patients with impaired renal function, the dose of rasburicase should be reduced and the patient should be closely monitored for the development of methemoglobinemia.

Pregnancy / Lactation

Pregnancy warnings:   

AU TGA pregnancy category: B2
US FDA pregnancy category: C

Lactation:

Excreted into human milk is unknown

Pregnancy Categories:     

Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester. 

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women.

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.  

Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.  

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.  

Category N: There is no data available for the drug under this category

Pharmacology

Pharmacology:

rasburicase is a recombinant urate oxidase enzyme that converts uric acid to allantoin, a more soluble and excretable compound. This mechanism of action helps to reduce the levels of uric acid in the blood, which can be useful in the management of hyperuricemia, particularly in patients with conditions such as leukemia, lymphoma, or solid tumors.

Pharmacodynamics:

The mechanism of action of rasburicase is mediated by its ability to bind to and catalyze the oxidation of uric acid, resulting in the formation of allantoin. This process is highly specific and efficient, with rasburicase exhibiting a high affinity for uric acid and a relatively low affinity for other purine metabolites.

The pharmacodynamics of rasburicase are characterized by a rapid onset of action and a relatively short duration of effect. The drug is typically administered as a single dose or a short course of treatment, and its effects on uric acid levels can be observed within hours of administration.

Pharmacokinetics:

Absorption

rasburicase is administered intravenously (IV) and is rapidly and completely absorbed into the bloodstream.

Distribution

The drug is distributed throughout the body, with high concentrations found in the liver and kidneys.

Metabolism

rasburicase is rapidly metabolized by the liver and kidneys, primarily through the action of urate oxidase.

Elimination and excretion

The drug is eliminated primarily through the urine, with less than 1% of the dose excreted in the feces. The half-life of rasburicase is approximately 20 minutes.

Adminstartion

Administration:

IV Administration

rasburicase is administered intravenously (IV) as a single dose.

The typical dosage is 0.20 mg/kg, given over a period of 15 minutes.

The medication should be administered under the supervision of a healthcare professional, and the patient’s blood glucose levels should be closely monitored during and after treatment.

It is important to note that rasburicase should not be used in patients with known hypersensitivity to the medication or any of its components.

Additionally, patients with glucose-6-phosphate dehydrogenase deficiency should not receive rasburicase.

Patient Information Leaflet

Patient information leaflet

Generic Name: rasburicase

Why do we use rasburicase?

rasburicase is used to lower high levels of uric acid in the blood, a condition called hyperuricemia. It is primarily used in patients with cancer who are undergoing chemotherapy, as the treatment can cause an increase in uric acid levels. High levels of uric acid can lead to the formation of uric acid crystals in the joints, leading to a condition called gout. rasburicase works by breaking down uric acid into a more soluble form, making it easier for the kidneys to remove it from the body.