Role of i.v. allopurinol and rasburicase in tumor lysis syndrome

The role of i.v. allopurinol and rasburicase in tumor lysis syndrome (TLS) is described. The current standard management for TLS consists of oral allopurinol in conjunction with i.v. hydration with or without alkalinization. Despite this standard prophylactic regimen, some high-risk patients may still develop urate nephropathy from TLS. Recently, i.v. allopurinol and rasburicase became available for the management of TLS. Available data on i.v. allopurinol indicate that the administration schedule and the adverse-effect profile will be similar to the oral formulation. The primary advantage of i.v. allopurinol is the flexibility of administration for patients who cannot take anything by mouth, since there are no data indicating the superiority of the i.v. to the oral product. Rasburicase is the first agent that will oxidize uric acid to allantoin, a metabolite with 5-10-fold greater solubility than uric acid, and reduces serum uric acid (SUA) levels within four hours of administration. Rasburicase is considerably more expensive than standard management strategies and should be reserved for patients with either renal dysfunction, significant elevations in SUA values, or large tumor burdens. Preliminary evidence indicates that rasburicase offers cost savings in the treatment of TLS and is cost-effective as a strategy for preventing TLS for many cancer patients. Both i.v. allopurinol and rasburicase offer additional flexibility in the management of TLS and may allow for further avoidance of the consequences of inadequate management of this syndrome.