Rasburicase

Rasburicase (brand names: Elitek in the US, and Fasturtec in Europe ) is a recombinant version of a urate oxidase enzyme that occurs in many mammals but not in humans.

Uses
Rasburicase is approved for use by the U.S. Food and Drug Administration (FDA) (and European counterparts) for the prevention and treatment of tumor lysis syndrome (TLS) in patients receiving chemotherapy for hematologic cancers such as leukemias and lymphomas. It is also being investigated for treating severe hyperuricemia from other sources (e.g., gout and other rheumatologic conditions).

It catalyses the conversion of uric acid to allantoin. Allantoin is an inactive metabolite of purine metabolism, and is five to ten times more soluble than uric acid, so renal excretion is more effective. Rasburicase is unique as a treatment and prevention for renal failure associated with TLS in that it catalyses the metabolism of existing uric acid. Other options prevent uric acid formation.

Rasburicase reduces the risk of renal failure and the need for transfusion. Transfusion has been reported as required in 17 to 25% of TLS cases treated with allopurinol, and 1.4% of cases treated with rasburicase.

However, rasburicase is much more expensive than conventional therapy.

Side effects
Side effects of rasburicase administration can include anaphylaxis (incidence unknown) and methemoglobinemia.