Flucytosine Mode of Action

Flucytosine is converted to antimetabolite 5-fluorouracil (5-FU) by the fungus, not human. 5-FU is subsequently converted to 5-fluorodeoxyuridine monophosphate (5-FdUMP)which inhibits THYMIDYLATE SYNTHETASE ENYZYME and thus DNA synthesis. Resistant mutant may occur. Thus, not used alone Shortened: 5-FdUMP or 5-fluorodeoxyuridine monophosphate inhibits Thymidylate Synthetase Enzyme (DNA Synthesis)