Pharmacokinetics of floxuridine in patients with trophoblastic Tumors

OBJECTIVE To investigate the disposition of floxuridine in patients with trophoblastic tumors.METHODS 12 patients with trophoblastic tumors were divided into FUDR and FUDR+KSM group.FUDR was administered by an 8 hour infusion.The blood samples were obtained during the infusion and up to 50 min after the infusion.The concentrations of floxuridine in serum were measured by a reverse phase high performance liquid chromatography.The pharmacokinetics of floxuridine was assessed by noncompartment and compartment model.RESULTS The disposition of floxuridine was nonlinear,consistent with a three compartment model.The metabolite fluorouracil was found after iv administration of floxuridine.CONCLUSION Floxuridine was eliminated primarily by a dose dependent process.Such characteristics may be related to unexpected stronger pharmacological effects if increasing the dose or reducing the infusion time.