[Pharmacokinetics of cis-dichlorodiammine platinum (II) in patients undergoing hemodialysis]

The pharmacokinetics of non-protein-bound platinum (free-Pt) and protein-bound platinum derived from cisplatin [cis-dichlorodiammine platinum (II), CDDP] were studied in five patients with chronic renal failure who developed gastric cancer during long-term hemodialysis. Plasma concentrations of CDDP were determined by atomic absorption spectrophotometry. CDDP at a dose of 25 mg/m2 was given i.v. over a 30-min period every one to two weeks. When CDDP was infused simultaneously with the start of hemodialysis, free-Pt at the blood inlet decreased rapidly and free-Pt at the blood outlet remained below the level for quantitative analysis. Furthermore, the total-Pt level declined in two exponential curves at the blood inlet simultaneously with the increased level of Pt at the blood outlet after the end of dialysis. In contrast, when CDDP was infused one hour earlier before dialysis, the pharmacokinetics revealed a higher concentration of free-Pt at the blood inlet which was maintained over a longer period as compared with that occurring when infused simultaneously with the start of dialysis. In conclusion it is considered that this method is feasible for the treatment of gastric cancer in patients with chronic renal failure under long-term hemodialysis.