Xanthine Nephropathy in a Patient with Lymphosarcoma Treated with Allopurinol

Abstract

ALLOPURINOL is an agent of proved value for the treatment of hyperuricemic and hyperuricosuric states.^{1 , 2} Both allopurinol and its principal metabolic product, oxypurinol, inhibit the enzyme xanthine oxidase that normally converts hypoxanthine to xanthine, and xanthine to uric acid.^{1 , 2} In hematopoietic cancer uric acid excretions may be increased two to four times.¹ Hyperuricemia and hyperuricosuria may become even more marked after therapy with anticancer agents or radiation. The rapid lysis of cells can lead to abrupt elevation of serum uric acid, hyperuricosuria, urinary-stone formation and urinary-tract obstruction. In these patients the prophylactic use of allopurinol is generally advised, the drug . . .