Pharmacokinetics of (glycolate-0,0')-diammine platinum (II), a new platinum derivative, in comparison with cisplatin and carboplatin.

The pharmacokinetics of (glycolato-0,0')-diammine platinum (II) (254-S; NSC 375101D), one of the new platinum analogues, was examined in a phase I study of this drug and compared with that of cisplatin and carboplatin. All drugs were given in short-term (30-min) i.v. drip infusions; the doses of 254-S, cisplatin, and carboplatin were 100, 80, and 450 mg/m2, respectively. Platinum concentrations in whole plasma, plasma ultrafiltrate, and urine were determined by atomic absorption spectrometry. After the infusion, the plasma concentration of total platinum for the three agents decayed biphasically. Ultrafilterable platinum in plasma decreased in a biexponential mode after infusions of 254-S and carboplatin, whereas the free platinum of cisplatin showed a monoexponential disappearance. The peak plasma concentrations and AUC for free platinum were 5.31 micrograms/ml and 959 micrograms/min per ml for 254-S, 3.09 micrograms/ml and 208 micrograms/min per ml for cisplatin, and 19.90 micrograms/ml and 3446 micrograms/min per ml for carboplatin, respectively. The mean ratio of plasma ultrafilterable platinum to total platinum were calculated, and the results showed that the protein-binding abilities of 254-S and carboplatin were almost identical. More than 50% of the 254-S was excreted in the urine within the first 480 min after its administration. Thrombocytopenia was reported as a dose-limiting toxicity for both 254-S and carboplatin. This similarity in side effects may mainly be due to the comparable pharmacokinetic behavior of these two platinum compounds.