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Flucytosine Dosage

Medically reviewed on March 12, 2018.

Applies to the following strengths: 250 mg; 500 mg

Usual Adult Dose for Candida Urinary Tract Infection

50 to 150 mg/kg/day orally in divided doses every 6 hours

Comments:
-This drug should be used in conjunction with amphotericin B for the treatment of systemic candidiasis and cryptococcosis (due to emerging resistance to this drug).
-Candida: Limited studies in pulmonary infections justify use of this drug.
-Cryptococcus: Limited trials in septicemias and urinary tract infections, but good responses reported.

Uses: For the treatment of serious infections due to susceptible strains of Candida (septicemia, endocarditis, urinary system infections, pulmonary infections) and/or Cryptococcus (meningitis, pulmonary infections, septicemia, urinary tract infections)

Infectious Diseases Society of America (IDSA) Recommendations: 100 mg/kg/day orally in 4 divided doses

Comments:
-In conjunction with amphotericin B (or fluconazole)
-Current guidelines should be consulted for additional information.

Usual Adult Dose for Candidemia

50 to 150 mg/kg/day orally in divided doses every 6 hours

Comments:
-This drug should be used in conjunction with amphotericin B for the treatment of systemic candidiasis and cryptococcosis (due to emerging resistance to this drug).
-Candida: Limited studies in pulmonary infections justify use of this drug.
-Cryptococcus: Limited trials in septicemias and urinary tract infections, but good responses reported.

Uses: For the treatment of serious infections due to susceptible strains of Candida (septicemia, endocarditis, urinary system infections, pulmonary infections) and/or Cryptococcus (meningitis, pulmonary infections, septicemia, urinary tract infections)

Infectious Diseases Society of America (IDSA) Recommendations: 100 mg/kg/day orally in 4 divided doses

Comments:
-In conjunction with amphotericin B (or fluconazole)
-Current guidelines should be consulted for additional information.

Usual Adult Dose for Cryptococcal Meningitis - Immunocompetent Host

50 to 150 mg/kg/day orally in divided doses every 6 hours

Comments:
-This drug should be used in conjunction with amphotericin B for the treatment of systemic candidiasis and cryptococcosis (due to emerging resistance to this drug).
-Candida: Limited studies in pulmonary infections justify use of this drug.
-Cryptococcus: Limited trials in septicemias and urinary tract infections, but good responses reported.

Uses: For the treatment of serious infections due to susceptible strains of Candida (septicemia, endocarditis, urinary system infections, pulmonary infections) and/or Cryptococcus (meningitis, pulmonary infections, septicemia, urinary tract infections)

Infectious Diseases Society of America (IDSA) Recommendations: 100 mg/kg/day orally in 4 divided doses

Comments:
-In conjunction with amphotericin B (or fluconazole)
-Current guidelines should be consulted for additional information.

Usual Adult Dose for Cryptococcal Meningitis - Immunosuppressed Host

50 to 150 mg/kg/day orally in divided doses every 6 hours

Comments:
-This drug should be used in conjunction with amphotericin B for the treatment of systemic candidiasis and cryptococcosis (due to emerging resistance to this drug).
-Candida: Limited studies in pulmonary infections justify use of this drug.
-Cryptococcus: Limited trials in septicemias and urinary tract infections, but good responses reported.

Uses: For the treatment of serious infections due to susceptible strains of Candida (septicemia, endocarditis, urinary system infections, pulmonary infections) and/or Cryptococcus (meningitis, pulmonary infections, septicemia, urinary tract infections)

Infectious Diseases Society of America (IDSA) Recommendations: 100 mg/kg/day orally in 4 divided doses

Comments:
-In conjunction with amphotericin B (or fluconazole)
-Current guidelines should be consulted for additional information.

Usual Adult Dose for Cryptococcosis

50 to 150 mg/kg/day orally in divided doses every 6 hours

Comments:
-This drug should be used in conjunction with amphotericin B for the treatment of systemic candidiasis and cryptococcosis (due to emerging resistance to this drug).
-Candida: Limited studies in pulmonary infections justify use of this drug.
-Cryptococcus: Limited trials in septicemias and urinary tract infections, but good responses reported.

Uses: For the treatment of serious infections due to susceptible strains of Candida (septicemia, endocarditis, urinary system infections, pulmonary infections) and/or Cryptococcus (meningitis, pulmonary infections, septicemia, urinary tract infections)

Infectious Diseases Society of America (IDSA) Recommendations: 100 mg/kg/day orally in 4 divided doses

Comments:
-In conjunction with amphotericin B (or fluconazole)
-Current guidelines should be consulted for additional information.

Usual Adult Dose for Fungal Endocarditis

50 to 150 mg/kg/day orally in divided doses every 6 hours

Comments:
-This drug should be used in conjunction with amphotericin B for the treatment of systemic candidiasis and cryptococcosis (due to emerging resistance to this drug).
-Candida: Limited studies in pulmonary infections justify use of this drug.
-Cryptococcus: Limited trials in septicemias and urinary tract infections, but good responses reported.

Uses: For the treatment of serious infections due to susceptible strains of Candida (septicemia, endocarditis, urinary system infections, pulmonary infections) and/or Cryptococcus (meningitis, pulmonary infections, septicemia, urinary tract infections)

Infectious Diseases Society of America (IDSA) Recommendations: 100 mg/kg/day orally in 4 divided doses

Comments:
-In conjunction with amphotericin B (or fluconazole)
-Current guidelines should be consulted for additional information.

Usual Adult Dose for Systemic Fungal Infection

50 to 150 mg/kg/day orally in divided doses every 6 hours

Comments:
-This drug should be used in conjunction with amphotericin B for the treatment of systemic candidiasis and cryptococcosis (due to emerging resistance to this drug).
-Candida: Limited studies in pulmonary infections justify use of this drug.
-Cryptococcus: Limited trials in septicemias and urinary tract infections, but good responses reported.

Uses: For the treatment of serious infections due to susceptible strains of Candida (septicemia, endocarditis, urinary system infections, pulmonary infections) and/or Cryptococcus (meningitis, pulmonary infections, septicemia, urinary tract infections)

Infectious Diseases Society of America (IDSA) Recommendations: 100 mg/kg/day orally in 4 divided doses

Comments:
-In conjunction with amphotericin B (or fluconazole)
-Current guidelines should be consulted for additional information.

Usual Pediatric Dose for Systemic Fungal Infection

Some Experts Recommend: 50 to 150 mg/kg/day orally in divided doses every 6 hours

Comments:
-A small number of neonates were treated with 25 to 200 mg/kg/day (with and without amphotericin B) for systemic candidiasis; no unexpected side effects were reported.
-According to some experts, this drug should be used in conjunction with amphotericin B.

Renal Dose Adjustments

Dose adjustments may be required; however, no specific guidelines have been suggested. Extreme caution recommended.

Comments:
-If BUN or serum creatinine is elevated (or there are other signs of renal dysfunction), the lower amount should be used for the initial dose.

Some Experts Recommend:
-CrCl 20 to 40 mL/min: 12.5 to 37.5 mg/kg orally every 12 hours
-CrCl 10 to 20 mL/min: 12.5 to 37.5 mg/kg orally every 24 hours
-CrCl less than 10 mL/min: 12.5 to 37.5 mg/kg orally every 24 to 48 hours or longer, depending on serum drug levels

Liver Dose Adjustments

Data not available

Precautions

US BOXED WARNING:
-RENAL IMPAIRMENT/MONITORING: This drug should be used with extreme caution in patients with renal dysfunction. Close monitoring of renal, hematologic, and hepatic status of all patients is essential. Instructions should be reviewed thoroughly before use of this drug.

Safety and efficacy have not been systematically studied in patients younger than 18 years.

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Comments:
-Hemodialysis rapidly reduces serum drug levels in anuric patients.

Some Experts Recommend:
-Patients undergoing hemodialysis every 48 to 72 hours: 20 to 50 mg/kg orally after dialysis session

Other Comments

Administration advice:
-May minimize or avoid nausea/vomiting if the capsules are administered a few at a time over 15 minutes
-Use in conjunction with amphotericin B for the treatment of systemic candidiasis and cryptococcosis (due to emerging resistance to this drug); according to some experts, may use with oral fluconazole in patients who cannot receive amphotericin B.

General:
-Duration of therapy depends on the nature and severity of the infection.

Monitoring:
-General: Serum drug levels (during therapy)
-Hematologic: Hematologic status including leukocyte and thrombocyte count (before and often during therapy); hematopoietic system (often during therapy)
-Hepatic: Liver function including alkaline phosphatase, ALT, and AST (often during therapy)
-Metabolic: Electrolytes (before and during therapy)
-Renal: Renal function (before and during therapy)

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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