Platinum kinetics in patients treated with cis-dichlorodiammine platinum (II)

The pharmacokinetics of platinum have been studied in six patients following treatment with cis-dichlorodiammine platinum (CDDP) for metastatic bladder cancer. Each patient received CDDP by 15 min intravenous infusion with total doses ranging from 90 to 120 mg (360 to 480 mg/h). Platinum disposition was biexponential with a relatively rapid distribution and slow elimination. Individual patient elimination half-lives varied from 16.1 to 53.3 h. Although normalized for body weight, individual distribution parameters, V1 and V area, varied from 0.17 to 0.70 L/kg and 0.67 to 1.47 L/kg, respectively. Total body clearance (TBC) also revealed considerable interpatient differences (7 to 40 ml/kg/h). Observed parameter variations could not be explained in terms of existing clinical data. These findings suggest that the pharmacokinetics of platinum in the individual patient might be difficult to predict, and thus serum platinum concentrations should be monitored during cis-dichlorodiammine platinum (II) therapy.