DefinePK

Abstract

The purpose of this study was to investigate the pharmacokinetics of mitomycin C when administered with ifosfamide and cisplatin as part of the mitomycin C, ifosfamide and cisplatin (MIC) regimen. Eleven patients with advanced non-small cell lung cancer, aged 49-73 years, were treated with mitomycin C (6 mg m-2), ifosfamide and cisplatin. Mitomycin C concentrations in plasma and erythrocytes were determined using HPLC with UV absorbance detection at 360 nm. The plasma β half life of mitomycin C was 44 min and the clearance 16.38 L h-1 m-2. A mean erythrocyte/plasma ratio of 0.87 (SD±0.35) was obtained. At low plasma concentrations, mitomycin C was undetectable in the erythrocyte. The mean plasma mitomycin C concentration when this occurred was 50 ng mL-1 (SD±35). The plasma pharmacokinetics of mitomycin C in the MIC regimen are consistent with the pharmacokinetic data obtained as a single agent, or as a component of other chemotherapy regimens. Mitomycin C is taken up into erythrocytes and is detectable within these cells for two hs following injection. The erythrocyte may act as a transporter of this compound in the circulation.