rasburicase + allopurinol

**rasburicase + allopurinol** is a combination of two pharmaceutical drugs used for the prevention and treatment of tumor lysis syndrome (TLS), particularly in patients with high tumor burden from hematologic malignancies such as leukemia and lymphoma. Rasburicase is a recombinant form of urate oxidase, an enzyme that catalyzes the conversion of uric acid to allantoin, a water-soluble compound, thus rapidly lowering pre-existing uric acid levels. Allopurinol is a structural isomer of hypoxanthine and acts as a xanthine oxidase inhibitor, thereby blocking the formation of new uric acid and decreasing both uric acid formation and total purine synthesis. The differing mechanisms of action allow the combination to target both existing and newly formed uric acid. Combination therapy has been used in clinical practice, but evidence suggests rasburicase alone may be more effective and efficient in rapidly lowering uric acid levels. Both drugs can be associated with adverse reactions, notably severe hypersensitivity syndromes such as Toxic Epidermal Necrolysis, with allopurinol having a well-established risk profile. The combination is primarily indicated for tumor lysis syndrome in oncology patients[1][2][3][4][5].