Interactions between UFT and anticoagulants in lung cancer patients.

In order to study the interactions between UFT and anticoagulants, the plasma and tissue concentrations of 5-FU, uracil and FT-207 were examined in patients with lung cancer. Higher plasma concentrations of 5-FU and uracil were observed in the patients who were given warfarin and ticlopidine beforehand, whereas the concentrations of FT-207 were almost the same in the patients who were given anticoagulants as in those who were not. This may be interpreted as an inhibition of dihydrouracil dehydrogenase, the common metabolizing enzyme of 5-FU and uracil, by anticoagulants. With regard to the tissue concentrations, higher levels of 5-FU and uracil in the tumor and lymph nodes were obtained after anticoagulants were given beforehand. Concentrations of FT-207 in these tissues, however, were almost the same in the patients who were given anticoagulants as in those who were not. We thus concluded that an increase of 5-FU in tumor cells and lymph nodes can be achieved after elevating the plasma concentrations of ordinary oral doses of UFT by using anticoagulation therapy beforehand.