Evaluation of Oral Amphotericin B with Serial Measurement of Serum Concentration in Patients with Leukemia and Related Disorders

: A total of 10 episodes in 7 patients with leukemia or related disorders was treated with oral amphotericin B (AMPH). In 8 episodes AMPH were used prophylactically for severe neutropenia, and in the remaining 2 it was given when the patients were feverish. A daily dose of 2,400 mg of AMPH was given orally once a day and serum concentrations of AMPH were determined serially with bioassay. Two hours after administration, the mean serum concentration of AMPH rose to 0.15 microgram/ml, and reached 0.27 microgram/ml after 24 hours. The concentration was maintained between 0.23 microgram/ml and 0.39 microgram/ml through the following 7 days. These concentrations exceed the minimal inhibitory concentrations of most strains of Candida albicans. In 8 occasions of prophylactic use, no fungal infection was encountered. In a patient with pneumonia, chest X-ray and physical findings improved with administration of oral AMPH. Side effect of AMPH was seen in 1 patient, which was mild proteinuria and was eased rapidly after the withdrawal of AMPH. Clinical laboratory tests showed 1 case of proteinuria and disorder of kidney but did not clear under influence of AMPH. These results suggest that oral administration of AMPH is clinically and therapeutically effective and relatively safe for the prophylaxis or the treatment of fungal infection in patients with leukemia or related disorders.