[The pharmacokinetics of intraperitoneal (IP) carboplatin (CBDCA) and dose-up study of intravenous (IV) cyclophosphamide (CPM) in combination with IP CBCDA for advanced ovarian cancer patients].

The pharmacokinetics of IP CBDCA was compared with IV CBDCA and a dose-up study of IV CPM was performed in combination with 400 mg/m2 IP CBDCA for advanced ovarian cancer patients. The maximum concentration of free platinum (F-Pt) in serum following IP CBDCA administration was approximately 1/3 that of F-Pt following IV CBDCA. F-Pt in serum remained more than 90% of total platinum following IP CBDCA until 12 hours after administration. The t1/2 of F-Pt in serum after IP CBDCA administration was two times longer when compared with t1/2 following IV CBDCA, showing the slow peritoneal clearance of CBDCA. The area under curve (AUC) following IP CBDCA was approximately 67% of AUC following IV CBDCA. Cumulative urinary secretion (CUS) of platinum following IP CBDCA was 37% of CUS after IV CBDCA. The maximum tolerable dose of IV CPM in combination with 400 mg/m2 IP CBDCA was 550-600 mg/m2. The dose limiting factor of this combination therapy was leukocytopenia. Thrombocytopenia was mild in this study. Combination of 400 mg/m2 IP CBDCA and 550-600 mg/m2 seemed to be a tolerable and repeatable therapy for most patients with advanced ovarian carcinoma. Since thrombocytopenia was mild and the pharmacokinetics showed the smaller AUC of free platinum in serum following IP CBDCA, a dose-up study for IP CBDCA should be considered.