Tegafur, Gimeracil and Oteracil potassium combination product: Serious blood dyscrasia and gastrointestinal disorder such as diarrhea and stomatitis may occur early when coadministered with Tegafur, Gimeracil and Oteracil potassium combination product. This drug should not be administered during the administration of this combination product or within at least 7 days after withdrawal of this combination.
Warfarin potassium: Since the effect of warfarin potassium may be enhanced by tegafur, caution should be exercised with respect to fluctuation of coagulating ability.
Contraindicated coadministration: Sorivudine. (Combined the antiviral drug sorivudine with fluorouracil-group drug (tegafur, doxifluridine, and 5-FU) may inhibit the metabolism of fluorouracil-group drug, resulting in elevated blood concentration, which may cause an adverse drug reaction such as severe blood dyscrasia.)
Careful coadministration: Phenytoin (The action of phenytoin may be intensified by this product.)
Other antimalignant tumor agents or radiation therapy. (Exaggerated adverse reactions might occur, such as bone marrow depression.)