[Study on changes in plasma platinum concentrations after administration of CDDP to maintenance hemodialysis...

Changes in plasma platinum concentration after administration of CDDP were studied in six patients on maintenance hemodialysis with malignancies. Plasma exchange was carried out on three patients for the purpose of plasmapheresis. A therapeutic dose of 51 mg/m2 of CDDP was administered to each patient without any severe adverse reactions. Plasma platinum concentration was measured by atomic absorption spectrophotometry, and the decay curve of the agent showed a biphasic pattern with an initial steep alpha phase and an ensuing mild beta phase in both hemodialysis patients and normal controls. As these patterns showed no renal excretion of CDDP, it was suggested that the uptake of CDDP into tissue was one of the main causes of the steep alpha phase. In patients given plasma exchange one or two hours after the beginning of CDDP administration, the reduction rates of plasma platinum were 74.7-61.7%, but the collection rate of the agent in the exchanged plasma was only 22.2-7.5%. These results indicated that the uptake of CDDP into tissue might occur rapidly within a few hours after CDDP administration.