Medical Information Only: This medication is not sold on this site. The information provided is for reference purposes only. Please consult your local physician or pharmacist for treatment.

Ancotil: Full Drug Profile

Medically reviewed by Min Clinic Staff | Updated: January 2026

Ancotil - General Information

A fluorinated cytosine analog that is used as an antifungal agent.

 

Pharmacology of Ancotil

Ancotil is an antimetabolite that acts as an antifungal agent with in vitro and in vivo activity against Candida and Cryptococcus. Ancotil 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. Antifungal synergism between Ancobon and polyene antibiotics, particularly amphotericin B, has been reported.

 

Ancotil for patients

Bone marrow toxicity can cause anemia, leukopenia, pancytopenia, thrombocytopenia and, rarely, agranulocytosis and eosinophilia. Other side effects can be nausea, vomiting, anorexia, bloating, diarrhea, and, rarely, bowel perforation. Reversible elevations in liver enzymes have been reported. Occasionally, rashes may be a side effect. Some side effects that have only been seen very rarely are confusion, hallucinations, headaches, sedation, vertigo and liver enlargement.There has also been a case of severe allergic-type reaction to the drug in at least one person with AIDS. This type of reaction is called anaphylaxis.

 

Ancotil Interactions

Cytosine arabinoside, a cytostatic agent, has been reported to inactivate the antifungal activity of flucytosine by competitive inhibition. Drugs which impair glomerular filtration may prolong the biological half-life of flucytosine.
Drug/Laboratory Test Interactions: Measurement of serum creatinine levels should be determined by the Jaffe reaction, since Ancobon does not interfere with the determination of creatinine values by this method. Most automated equipment for measurement of creatinine makes use of the Jaffe reaction.

 

Ancotil Contraindications

5-Flucytosine should not be used in patients with a known hypersensitivity to the drug.

 

Additional information about Ancotil

Ancotil Indication

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).

Mechanism Of Action
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. Ancotil 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.
Generic Name
Flucytosine
Synonyms
5-FC; 5-Fluorocystosine; 5-Fluorocytosin; 5-Fluorocytosine; 5-Flurocytosine; Flucytosin; Fluocytosine; Fluorcytosine
Drug Category
Antimetabolites; Antifungals
Drug Type
Small Molecule; Approved
Other Brand Names containing Flucytosine
Ancobon; Ancotil;
Absorption
Rapidly and virtually completely absorbed following oral administration. Bioavailability 78% to 89%.
Toxicity (Overdose)
Oral, rat: LD50 = >15 gm/kg.
Protein Binding
28-31%
Biotransformation
Flucytosine is deaminated, possibly by gut bacteria or by the fungal targets, to 5-fluorouracil, the active metabolite.
Half Life
2.4 to 4.8 hours.
Dosage Forms of Ancotil
Capsule Oral
Chemical IUPAC Name
4-amino-5-fluoro-3H-pyrimidin-2-one
Chemical Formula
C4H4FN3O
Organisms Affected
Yeast and other fungi