[Biliary and pancreatic excretion of methotrexate (MTX) and 5-FU on the MTX/5-FU sequential therapy].

On the postoperative adjuvant MTX/5-FU sequential therapy, biliary and pancreatic excretion of both drugs was studied through the hepatic and pancreatic drainages in pancreatoduodenectomized patients. MTX: 100 mg/m2 of bolus injection and 5-FU: 800 mg/m2 of sequential one hour drip infusion were used in this series. Biliary excretion of MTX was reached peak concentration at 90 min, its mean value being 5 fold of serum concentration. During the observation period of 4.5 hours, the recovery of MTX in bile was calculated as 3-12% which presumed to be more because of still continuing biliary excretion on the terminal observation. Pancreatic excretion of MTX was minimal and not so as to have further clinical meaning. Though the serum concentration of 5-FU was raised up with its infusion, biliary and pancreatic outputs of 5-FU were small, each value showing one third compared with at a single shot of the same doses. From the obtained mode and time lag of concentration curves of both drugs, the rationale of per oral and earlier administration of Leucovorin was discussed as a possible way of removal of MTX from intestine.