Cyclophosphamide and other cytotoxic agents (bone marrow suppression);
the allopurinol hypersensitivity syndrome is characterized by fever, eosinophilia, leukocytosis, impaired renal function, hepatocellular injury and rash;
these reactions are severe and may be fatal;
allopurinol should be used carefully with those w/ renal insufficiency, a h/o uric acid stones and those with a 24 hour urinary acid excretion over 1,100 mg
