pharmacopeia
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/api/v1/drug/flucytosine

Boxed warning

Use with extreme caution in patients with impaired renal function. Close monitoring of hematologic, renal and hepatic status of all patients is essential. These instructions should be thoroughly reviewed before administration of Flucytosine Capsules USP.

Mechanism of action

Sourced from openFDA

Mechanism-of-action class: Protein Synthesis Inhibitors.

Protein Synthesis

Indications

Sourced from openFDA
  • Flucytosine Capsules USP is indicated only in the treatment of serious infections caused by susceptible strains of Candida and/or Cryptococcus . Candida: Septicemia, endocarditis and urinary system infections have been effectively treated with flucytosine.

Contraindications

Sourced from openFDA
  • Flucytosine Capsules, USP is contraindicated in patients with a known hypersensitivity to the drug. Flucytosine Capsules, USP is contraindicated in patients with known complete dihydropyrimidine dehydrogenase (DPD) enzyme deficiency (see WARNINGS ).contraindicated

Dosage & administration

Sourced from openFDA

The usual dosage of Flucytosine Capsules USP is 50 to 150 mg/kg/day administered in divided doses at 6-hour intervals. Nausea or vomiting may be reduced or avoided if the capsules are given a few at a time over a 15-minute period. If the BUN or the serum creatinine is elevated, or if there are other signs of renal impairment, the initial dose should be at the lower level (see WARNINGS ). Flucytosine Capsules USP should be used in combination with amphotericin B for the treatment of systemic candidiasis and cryptococcosis because of the emergence of resistance to Flucytosine Capsules USP (See MICROBIOLOGY ).

Warnings & precautions

Sourced from openFDA

Flucytosine Capsules USP must be given with extreme caution to patients with impaired renal function. Since Flucytosine Capsules USP is excreted primarily by the kidneys, renal impairment may lead to accumulation of the drug. Flucytosine Capsules USP serum concentrations should be monitored to determine the adequacy of renal excretion in such patients. Dosage adjustments should be made in patients with renal insufficiency to prevent progressive accumulation of active drug. Flucytosine Capsules USP must be given with extreme caution to patients with bone marrow depression. Patients may be more prone to depression of bone marrow function if they: 1) have a hematologic disease, 2) are being treated with radiation or drugs which depress bone marrow, or 3) have a history of treatment with such drugs or radiation. Bone marrow toxicity can be irreversible and may lead to death in immunosuppressed patients. Frequent monitoring of hepatic function and of the hematopoietic system is indicated during therapy. 5-Fluorouracil is a metabolite of flucytosine. Dihydropyrimidine dehydrogenase is a key enzyme involved in the metabolism and elimination of 5-fluorouracil. Therefore, the risk of severe drug toxicity is increased when Flucytosine Capsules, USP is used in individuals with deficiency in DPD. Possible drug toxicities include mucositis, diarrhea, neutropenia, and neurotoxicity. Determination of DPD activity may be considered where drug toxicity is confirmed or suspected. In the event of suspected drug toxicity, consider stopping Flucytosine Capsules USP, treatment.

Adverse reactions

Sourced from openFDA

The adverse reactions which have occurred during treatment with Flucytosine Capsules USP are grouped according to organ system affected. Cardiovascular: Cardiac arrest, myocardial toxicity, ventricular dysfunction. Respiratory: Respiratory arrest, chest pain, dyspnea. Dermatologic: Rash, pruritus, urticaria, photosensitivity. Gastrointestinal: Nausea, emesis, abdominal pain, diarrhea, anorexia, dry mouth, duodenal ulcer, gastrointestinal hemorrhage, acute hepatic injury including hepatic necrosis with possible fatal outcome in debilitated patients, hepatic dysfunction, jaundice, ulcerative colitis, enterocolitis, bilirubin elevation, increased hepatic enzymes. Genitourinary: Azotemia, creatinine and BUN elevation, crystalluria, renal failure. Hematologic: Anemia, agranulocytosis, aplastic anemia, eosinophilia, leukopenia, pancytopenia, thrombocytopenia, and fatal cases of bone marrow aplasia. Neurologic: Ataxia, hearing loss, headache, paresthesia, parkinsonism, peripheral neuropathy, pyrexia, vertigo, sedation, convulsions. Psychiatric: Confusion, hallucinations, psychosis. Miscellaneous: Fatigue, hypoglycemia, hypokalemia, weakness, allergic reactions, Lyell's syndrome. To report SUSPECTED ADVERSE REACTIONS, contact Lupin Pharmaceuticals, Inc. at 1-866-403-7592 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Use in specific populations

Sourced from openFDA

Pregnancy Teratogenic Effects Flucytosine was shown to be teratogenic (vertebral fusions) in the rat at doses of 40 mg/kg/day (298 mg/M 2 /day or 0.051 times the human dose) administered on days 7 to 13 of gestation. At higher doses (700 mg/kg/day; 5208 mg/M 2 /day or 0.89 times the human dose administered on days 9 to 12 of gestation), cleft lip and palate and micrognathia were reported. Flucytosine was not teratogenic in rabbits up to a dose of 100 mg/kg/day (1423 mg/M 2 /day or 0.243 times the human dose) administered on days 6 to 18 of gestation. In mice, 400 mg/kg/day of flucytosine (1380 mg/M 2 /day or 0.236 times the human dose) administered on days 7 to 13 of gestation was associated with a low incidence of cleft palate that was not statistically significant. Studies in pregnant rats have shown that flucytosine injected intraperitoneally crosses the placental barrier. There are no adequate and well-controlled studies in pregnant women. Flucytosine Capsules USP should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Overdosage

Sourced from openFDA

There is no experience with intentional overdosage. It is reasonable to expect that overdosage may produce pronounced manifestations of the known clinical adverse reactions. Prolonged serum concentrations in excess of 100 mcg/mL may be associated with an increased incidence of toxicity, especially gastrointestinal (diarrhea, nausea, vomiting), hematologic (leukopenia, thrombocytopenia) and hepatic (hepatitis). 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 Flucytosine Capsules USP 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.

Approval history

Sourced from openFDA
  • Nov 26, 1971NDANDA017001Bausch
  • Jun 28, 2011ANDAANDA201566Sigmapharm Labs Llc
  • Jul 7, 2017ANDAANDA204652Novel Labs Inc
  • Apr 17, 2020ANDAANDA212632Strides Pharma
  • May 1, 2020ANDAANDA213665Aurobindo Pharma Ltd
  • Jul 23, 2025ANDAANDA218005Laurus

FAERS reports

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Reference statistics only. FAERS reports are voluntarily submitted and are not incidence rates, safety signals, or causal evidence. Counts reflect reporting volume — how often a reaction was reported, not how often it occurs. For decision-grade use, consult openFDA and the FAERS Public Dashboard directly.
1,327 total reports matchedLatest report Share = reports listing the reaction ÷ total matched reports. Rows can sum to >100% because a single report often lists multiple reactions.
  1. 1Drug Ineffective44133%
  2. 2Off Label Use1299.7%
  3. 3Immune Reconstitution Inflammatory Syndrome1027.7%
  4. 4Meningitis Cryptococcal926.9%
  5. 5Acute Kidney Injury876.6%
  6. 6Renal Impairment725.4%
  7. 7Condition Aggravated675.0%
  8. 8Disseminated Cryptococcosis614.6%
  9. 9Cryptococcosis604.5%
  10. 10Pyrexia584.4%
  11. 11Headache574.3%
  12. 12Renal Failure564.2%
  13. 13Drug Interaction483.6%
  14. 14Drug Ineffective For Unapproved Indication473.5%
  15. 15Neutropenia443.3%

Literature

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Recent PubMed references pinned to Flucytosine as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

Clinical trials

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The 10 most recently updated of 48 ClinicalTrials.gov registrations naming Flucytosine as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

Frequently asked questions

How does Flucytosine work?
Mechanism-of-action class: Protein Synthesis Inhibitors.
What is Flucytosine used for?
According to FDA labeling, Flucytosine carries indications including: Flucytosine Capsules USP is indicated only in the treatment of serious infections caused by susceptible strains of Candida and/or Cryptococcus . Candida: Septicemia, endocarditis and urinary system infections have been effectively treated with flucytosine.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.
What class of drug is Flucytosine?
Flucytosine is classified as Other antifungals for topical use, Other antimycotics for systemic use, Nucleoside Analog Antifungal, Protein Synthesis Inhibitors, RNA Integrity Alteration.
What are the brand names for Flucytosine?
Flucytosine is marketed under brand names including Ancobon.
What are the contraindications for Flucytosine?
Flucytosine labeling lists contraindications including: Flucytosine Capsules, USP is contraindicated in patients with a known hypersensitivity to the drug. Flucytosine Capsules, USP is contraindicated in patients with known complete dihydropyrimidine dehydrogenase (DPD) enzyme deficiency (see WARNINGS ).. Always consult the full prescribing information and a clinician.
Note. Data for flucytosine is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.

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