Flucytosine

**Semantic type:** Nucleic Acid, Nucleoside, or Nucleotide|Pharmacologic Substance

**Definition:** A pyrimidine compound and a fluorinated cytosine analog exhibiting antifungal activity. After penetration into the fungal cells, flucytosine is deaminated to its active metabolite 5-fluorouracil. 5-fluorouracil replaces uracil during fungal RNA synthesis, thereby inhibiting fungal protein synthesis. In addition, fluorouracil is further metabolized to 5-fluorodeoxyuridylic acid monophosphate, which inhibits thymidylate synthetase, thereby interrupting nucleotide metabolism, DNA synthesis and ultimately protein synthesis.

**Synonyms:** - 4-Amino-5-fluoro-2(1H)-pyrimidinone - 4-Amino-5-fluoro-2(1H)-pyrimidinone - 5-FC - 5-FC - 5-Fluorocytosine - 5-Fluorocytosine - Alcobon - Ancobon - Ancobon - Ancotil - Ancotil - FLUCYTOSINE - Ro 2-9915 - Ro-2-9915 - flucytosine