RESUMO
This is a preliminary feasibility study to assess the pharmacokinetics and efficacy of pentostatin in a patient undergoing dialysis. Pentostatin is a safe and well-tolerated medication, but a dose reduction is required for patients with renal insufficiency. We present a patient with chronic adult T-cell leukemia, whose white blood cell count exceeded 100 X 10(9)/l, and end-stage renal disease, receiving long-term thrice-weekly dialysis. The initial treatment with oral cyclophosphamide or with oral etoposide resulted in no response. After informed consent was obtained, pentostatin (1, 2, or 3mg/m2) was administered. 1 or 2 hours after injection, the patient received hemodialysis over 4 hours to remove any of the drug remaining in his system. Plasma concentrations of pentostatin were calculated with the known pharmacokinetics parameters. The differential equations describing a 2-compartment open-infusion pharmacokinetic model were fitted to the measured concentration-time data. Tumor lysis syndrome occurred 4 days after the course of the highest dose (3mg/m2), and the patient achieved complete remission. Anorexia, graded as 2 according to the NCI-CTC classification system, occurred and continued for four weeks. Pentostatin therapy consisting of the decreased dose (2mg/m2) was then administered every other week and provided a transient partial response with mild anorexia. Consequently, pentostatin can be considered as one of the chemotherapeutic regimens available for a patient undergoing dialysis.
