Its use should be avoided in patients receiving drugs known to modulate dihydropyrimidine dehydrogenase (such as the antiviral drug sorivudine). It may also increase the INR and prothrombin times in patients on warfarin.<unk> 's efficacy is decreased when used alongside allopurinol, which can be used to decrease<unk>  induced stomatitis through use of allopurinol mouthwash.
Fluorouracil
Ifosfamide
Vincristine
Normustine
Etoposide
Doxorubicin
Gemcitabine
GemOx