Flucytosine

Generic name
Flucytosine
Brand name
ATC Code
J02AX01
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Flucytosine

Dosages
Side effects in children
Warnings & precautions in children
Contra-indications in children

Interactions
PK
Renal impairment
References

Pharmacokinetics in children

Baley et al. have shown that there is strong inter-individual variation in the pharmacokinetics of flucytosine in neonates (N=13). The half-life in neonates is 4-34 hours. As a result of the immature renal function, the flucytosine serum concentration in neonates is considerably higher than in older children. The serum concentration in older children (3 months – 12 years) is equivalent to the serum concentration reported in adults. 

dose recommendation of formulary compared to licensed use (on-label versus off-label)

No information is present at this moment.

Available formulations

No information is present at this moment.

Dosages

Generalized mycoses caused by sensitive pathogens (combined with amphotericin B in chronic and difficult-to-treat forms of mycosis)
  • Oral
    • Term neonate
      [2]
      • 50 - 100 mg/kg/day in 1 - 2 doses.

      • Titrate the dose depending on the concentrations. (See warnings and precautions)

    • 1 month up to 18 years
      [3] [4] [5]
      • 100 - 150 mg/kg/day in 4 doses.

      • Titrate the dose depending on the concentrations. (See warnings and precautions)

  • Intravenous
    • Term neonate
      [2]
      • 50 - 100 mg/kg/day in 1 - 2 doses.

      • Titrate the dose depending on the concentrations. (See warnings and precautions)

    • 1 month up to 18 years
      [3] [4] [5]
      • 100 - 150 mg/kg/day in 4 doses.

      • Titrate the dose depending on the concentrations. (See warnings and precautions)

Renal impaiment in children > 3 months

Adjustment in renal impairment as specified:

GFR 50-80 ml/min/1.73 m2
Dose adjustment not needed
GFR 30-50 ml/min/1.73 m2
On day 1: 100% of normal single dose and interval between 2 doses: 12 hours. Thereafter, adjust according to bloodlevels.
GFR 10-30 ml/min/1.73 m2
On day 1: 100% of normal single dose and interval between two doses: 24 hours. Thereafter, adjust according to bloodlevels.
GFR < 10 ml/min/1.73 m2
On day 1: 100% of normal single dose and interval between two doses: 24 hours. Thereafter, adjust according to levels.

The complete list of all undesirable drug reactions can be found in the national Summary of Product Characteristics (SmPC) – click here

Side effects in children

Nausea, vomiting, diarrhoea, headache, sleepiness, confusion, hallucinations, blood abnormalities, elevated serum liver enzymes, impaired liver function.

The complete list of all contra-indications can be found in the national Summary of Product Characteristics (SmPC) – click here

Contra-indications

No information available on specific contra indications in children.

The complete list of all warnings and precautions can be found in the national Summary of Product Characteristics (SmPC) – click here

Warnings & precautions in children

Flucytosine should only be prescribed in consultation with a paediatrician/infectiologist and/or a medical microbiologist. Blood count and hepatic and renal function must be checked regularly before and during the treatment. Combination with amphotericin B in particular requires careful monitoring of the renal function.

Level determination in intravenous/oral administration:
< include information if warranted from www.tdm-monografie.org>

Interactions

The complete list of all interactions can be found in the national Summary of Product Characteristics (SmPC) – click here

ANTIMYCOTICS FOR SYSTEMIC USE

This pages provides a list of drugs from the same ATC class for comparison. This does not necessarily mean that these drugs are interchangeable.

Antibiotics
J02AA01
Triazole and tetrazole derivatives
J02AC01
J02AC02
J02AC03
Other antimycotics for systemic use
J02AX06
J02AX04
J02AX05

References

  1. Hartwig NC, et al, Vademecum pediatrische antimicrobiele therapie, 2005
  2. Baley JE, et al, Pharmacokinetics, outcome of treatment, and toxic effects of amphotericin B and 5-fluorocytosine in neonates, J Pediatr., 1990, 116, 791-7
  3. Hope WW, et al, Optimization of the dosage of flucytosine in combination with amphotericin B for disseminated candidiasis: a pharmacodynamic rationale for reduced dosing, Antimicrob Agents Chemother., 2007, 51(10), 3760-2
  4. Pasqualotto AC, et al, Flucytosine therapeutic monitoring: 15 years experience from the UK, J Antimicrob Chemother, 2007, 59, 791-3
  5. Soltani M, et al, Evidence of excessive concentrations of 5-flucytosine in children aged below 12 years: a 12-year review of serum concentrations from a UK clinical assay reference laboratory, Int J Antimicrob Agents, 2006, 28, 574-7

Changes

Therapeutic Drug Monitoring


Overdose