5-Flucytosine

Flucytosine (5-Fluorocytosine, 5-FC, Ancobon), a fluorinated pyrimidine analogue, is an antifungal drug.Target: antifungalFlucytosine, or 5-fluorocytosine, a fluorinated pyrimidine analogue, is a synthetic antimycotic drug. It is structurally related to the cytostatic fluorouracil and to floxuridine. It is available in oral and in some countries also in injectable form. A common brand name is Ancobon. Flucytosine was first synthesized in 1957 but its antifungal properties were discovered in 1964. The drug is dispensed in capsules of 250 mg and 500 mg strength. The injectable form is diluted in 250 mL saline solution to contain 2.5 g total (10 mg/mL). The solution is physically incompatible with other drugs including amphotericin B.Flucytosine is well absorbed (75 to 90%) from the gastrointestinal tract. Intake with meals slows the absorption, but does not decrease the amount absorbed. Following an oral dose of 2 grams peak serum levels are reached after approximately 6 hours. The time to peak level decreases with continued therapy. After 4 days peak levels are measured after 2 hours. The drug is eliminated renally. In normal patients flucytosine has reportedly a half-life of 2.5 to 6 hours. In patients with impaired renal function higher serum levels are seen and the drug tends to cumulate in these patients. The drug is mainly excreted unchanged in the urine (90% of an oral dose) and only traces are metabolized and excreted in the feces. Therapeutic serum levels range from 25 to 100 ?g/ml. Serum levels in excess of 100 ug are associated with a higher incidence of side effects. Periodic measurements of serum levels are recommended for all patients and are a must in patients with renal damage.

Signaling Pathways >> Anti-infection >> Fungal

Research Areas >> Infection

[1]. Vermes A, et al. Flucytosine: a review of its pharmacology, clinical indications, pharmacokinetics, toxicity and drug interactions. J Antimicrob Chemother. 2000 Aug;46(2):171-9.

[2]. Te Dorsthorst DT, et al. In vitro interaction of flucytosine combined with amphotericin B or fluconazole against thirty-five yeast isolates determined by both the fractional inhibitory concentration index and the response surface approach. Antimicrob Agen

Cycloheximide | Hygromycin B | Cancidas | Posaconazole | Terbinafine | Ciclopirox | Isavuconazole | Anidulafungin | Clotrimazole | Clioquinol | Miconazole Nitrate | Pimaricin | Ascomycin | Econazole (nitrate) | Triclosan

MOLECULAR FORMULA :

C4-H4-F-N3-O

MOLECULAR WEIGHT :

129.11

WISWESSER LINE NOTATION :

T6MVNJ DZ EF

HEALTH HAZARD DATA

ACUTE TOXICITY DATA

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Human - woman

DOSE/DURATION :

1080 mg/kg/10D-I

TOXIC EFFECTS :

Brain and Coverings - other degenerative changes Behavioral - changes in motor activity (specific assay) Behavioral - ataxia

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

>15 gm/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

3811 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

3336 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intravenous

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

>600 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

>15 gm/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

1190 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

1 gm/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intravenous

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

500 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

MUTATION DATA

TYPE OF TEST :

Mutation in microorganisms

TEST SYSTEM :

Yeast - Saccharomyces cerevisiae

DOSE/DURATION :

8 mg/L

REFERENCE :

MGGEAE Molecular and General Genetics. (Springer-Verlag, Heidelberger Pl. 3, D-1000 Berlin 33, Fed. Rep. Ger.) V.99- 1967- Volume(issue)/page/year: 146,253,1976 *** REVIEWS *** TOXICOLOGY REVIEW 32XPAD "Teratology," Berry, C.L., and D.E. Poswillo, eds., New York, Springer, 1975 Volume(issue)/page/year: -,49,1975 *** NIOSH STANDARDS DEVELOPMENT AND SURVEILLANCE DATA *** NIOSH OCCUPATIONAL EXPOSURE SURVEY DATA : NOES - National Occupational Exposure Survey (1983) NOES Hazard Code - X6122 No. of Facilities: 53 (estimated) No. of Industries: 1 No. of Occupations: 2 No. of Employees: 1033 (estimated) No. of Female Employees: 480 (estimated)