Antimicrobial
Flucytosine
5-FC converted to antifungal 5-FU
floo-SY-toh-seen
High-yield clue
Fungal cytosine deaminase converts flucytosine to 5-FU, which impairs fungal DNA/RNA synthesis; human cells lack this enzyme.
Overview
A pyrimidine-analog antifungal (5-FC) studied for uptake by fungal cytosine permease and conversion by cytosine deaminase to 5-fluorouracil, disrupting fungal nucleic acid synthesis.
Classification
- Antifungal pyrimidine analog
- Prodrug converted by fungal cytosine deaminase
- Yields 5-fluorouracil
- Inhibits fungal DNA/RNA synthesis
Lab & identification clues
- Fungal-selective cytosine deaminase activation concept
- Rapid monotherapy resistance vocabulary
- Bone-marrow suppression monitoring concept
Associations
- Cryptococcal and Candida study associations
- In-vitro synergy with polyene cell-membrane agents framed as a mechanism concept
- Selective toxicity from absent human cytosine deaminase
Commonly confused with
- Azoles
- Polyenes
Frequently asked questions
What is Flucytosine?
A pyrimidine-analog antifungal (5-FC) studied for uptake by fungal cytosine permease and conversion by cytosine deaminase to 5-fluorouracil, disrupting fungal nucleic acid synthesis.
What is the high-yield clue for Flucytosine?
Fungal cytosine deaminase converts flucytosine to 5-FU, which impairs fungal DNA/RNA synthesis; human cells lack this enzyme.
What is Flucytosine associated with?
Flucytosine is associated with Cryptococcal and Candida study associations, In-vitro synergy with polyene cell-membrane agents framed as a mechanism concept, and Selective toxicity from absent human cytosine deaminase.
What is Flucytosine commonly confused with?
Flucytosine is commonly confused with Azoles and Polyenes.
Original mechanism summary for microbiology study. Sources checked: CDC antimicrobial-resistance guidance, NCBI Bookshelf Medical Microbiology, and standard coursework frameworks; reviewed 2026-06. Covers class, mechanism, and resistance vocabulary only; no prescribing, dosing, or patient-specific treatment guidance.