[Pharmacokinetic analysis of intra-peritoneal administration of cisplatin]

Pharmacokinetic parameters after intra-peritoneal administration of cis-platinum (CDDP) were evaluated and compared with those after intravenous administration. CDDP at a dose of 70 mg/m2 were administered intra-peritoneally in 5 patients with advanced gastric cancer (IP group). Pharmacokinetic parameters and toxicities were evaluated in these patients and compared with those in 4 esophageal cancer patients administered the same dose of CDDP intravenously (IV group). In IP group, Cmax of total- and free-Pt were 3.41 +/- 0.89 micrograms/ml and 1.10 +/- 0.30 micrograms/ml, and AUC of total- and free-Pt were 59.6 +/- 14.3 micrograms.hr/ml, 3.12 +/- 0.89 micrograms.hr/ml, respectively. On the other hand, Cmax and AUC of total- and free-Pt in IV group were 3.31 +/- 0.59 micrograms/ml. 1.13 +/- 0.21 micrograms/ml and 45.89 +/- 9.24 micrograms.hr/ml, 1.22 +/- 0.8 micrograms.hr/ml, respectively. AUC of free-Pt in IP group was significantly higher than in IV group. This result suggests that a more promising antitumor effect will be obtained systemically by intraperitoneal administration of CDDP. The incidence and grade of toxicities were similar in these two groups.