3025 T3D2983 Flucytosine Flucytosine is only found in individuals that have used or taken this drug. It is a fluorinated cytosine analog that is used as an antifungal agent. [PubChem]Although the exact mode of action is unknown, it has been proposed that flucytosine acts directly on fungal organisms by competitive inhibition of purine and pyrimidine uptake and indirectly by intracellular metabolism to 5-fluorouracil. Flucytosine enters the fungal cell via cytosine permease; thus, flucytosine is metabolized to 5-fluorouracil within fungal organisms. The 5-fluorouracil is extensively incorporated into fungal RNA and inhibits synthesis of both DNA and RNA. The result is unbalanced growth and death of the fungal organism. It also appears to be an inhibitor of fungal thymidylate synthase. 2022-85-7 3366 C4H4FN3O 129.033840 White powder. 296°C 1.5E+004 mg/L (at 25°C) Rapidly and virtually completely absorbed following oral administration. Bioavailability 78% to 89%. Although the exact mode of action is unknown, it has been proposed that flucytosine acts directly on fungal organisms by competitive inhibition of purine and pyrimidine uptake and indirectly by intracellular metabolism to 5-fluorouracil. Flucytosine enters the fungal cell via cytosine permease; thus, flucytosine is metabolized to 5-fluorouracil within fungal organisms. The 5-fluorouracil is extensively incorporated into fungal RNA and inhibits synthesis of both DNA and RNA. The result is unbalanced growth and death of the fungal organism. It also appears to be an inhibitor of fungal thymidylate synthase. Flucytosine is deaminated, possibly by gut bacteria or by the fungal targets, to 5-fluorouracil, the active metabolite. Route of Elimination: Flucytosine is excreted via the kidneys by means of glomerular filtration without significant tubular reabsorption. A small portion of the dose is excreted in the feces. Half Life: 2.4 to 4.8 hours. LD50: 15 gm/kg (Oral, Rat) (A308) No indication of carcinogenicity to humans (not listed by IARC). For the treatment (in combination with amphotericin B) of serious infections caused by susceptible strains of Candida (septicemia, endocarditis and urinary system infections) and/or Cryptococcus (meningitis and pulmonary infections). In the management of overdosage, prompt gastric lavage or the use of an emetic is recommended. Adequate fluid intake should be maintained, by the intravenous route if necessary, since Ancobon is excreted unchanged via the renal tract. The hematologic parameters should be monitored frequently; liver and kidney function should be carefully monitored. Should any abnormalities appear in any of these parameters, appropriate therapeutic measures should be instituted. Since hemodialysis has been shown to rapidly reduce serum concentrations in anuric patients, this method may be considered in the management of overdosage. (L1712) 2009-07-21T20:28:21Z 2014-12-24T20:25:54Z Flucytosine 5100 Flucytosine DB01099 true OC1=NC=C(F)C(=N)N1 C4H4FN3O InChI=1S/C4H4FN3O/c5-2-1-7-4(9)8-3(2)6/h1H,(H3,6,7,8,9) InChIKey=XRECTZIEBJDKEO-UHFFFAOYSA-N 129.0925 129.03383997 Exogenous Solid -1.1 HMDB15231 CHEMBL1463 3249 <p>Bernd Baasner, Erich Klauke, &#8220;Process for the preparation of 5-fluorocytosine.&#8221; U.S. Patent US4703121, issued September, 1961.</p>