OBJECTIVES: I. Compare the efficacy of liposomal nystatin vs standard amphotericin B for the empiric treatment of persistent febrile neutropenic patients. II. Compare the incidence of drug-related toxicity or impairment and infusion-related toxicity in patients treated with liposomal nystatin vs standard amphotericin B. III. Determine the pharmacokinetics of liposomal nystatin.