Classifications: antibiotic; antifungal; Therapeutic: antibiotic; antifungal
Pregnancy Category: C
250 mg, 500 mg capsules
Ineffective for cancerous tumors possibly because it does not enter mammalian cells. Selectively penetrates fungal cell and
is converted to fluorouracil, an antimetabolite believed to be responsible for antifungal activity.
Has antifungal activity against Cryptococcus and Candida as well as Chromomycosis.
Alone or in combination with amphotericin B for serious systemic infections caused by susceptible strains of Cryptococcus and Candida species.
Pregnancy (category C), lactation.
Extreme caution in impaired kidney function; hepatic disease; electrolyte imbalance; bone marrow depression, hematologic disorders,
patients being treated with or having received radiation or bone marrow depressant drugs.
Route & Dosage
Adult: PO 50150 mg/kg/d divided q6h
Child: PO <50 kg, 1.54.5 g/m2/d divided q6h; >50 kg, 50150 mg/kg/d divided q6h
Neonate: PO 50100 mg/kg/d in 12 divided doses
- Give lower dosages with longer dosage intervals in patients with serum creatinine of 1.7 mg/dL or higher. Check with physician.
- Give capsules a few at a time over 15 min to decrease incidence and severity of nausea and vomiting.
- Store in light-resistant containers at 15°30° C (59°86° F).
Adverse Effects (≥1%)CNS:
Confusion, hallucinations, headache, sedation, vertigo. GI:
Nausea, vomiting, diarrhea
, abdominal bloating, enterocolitis. Hematologic:
Hypoplasia of bone marrow
, eosinophilia. Skin:
Elevated levels of serum alkaline phosphatase
, AST, ALT, BUN, serum creatinine
Diagnostic Test Interference
False elevations of serum creatinine can occur with Ektachem analyzer.
InteractionsDrug: Amphotericin B
produces additive or synergistic effects and can increase flucytosine toxicity
by inhibiting its renal
Readily from GI tract. Peak:
2 h. Distribution:
Widely distributed in body tissues including aqueous humor and CSF; crosses placenta. Metabolism:
7590% in urine unchanged. Half-Life:
Assessment & Drug Effects
- C&S tests should be performed before initiation of therapy and at weekly intervals during therapy. Organism resistance has
- Lab tests: Obtain baseline hematology, kidney and liver function on all patients before and at frequent intervals during therapy.
Twice weekly leukocyte and differential counts with WBC with differential and platelet counts are recommended.
- Do frequent assays of blood drug level, especially in patients with impaired kidney function to determine adequacy of drug
excretion (therapeutic range: 25120 mg/mL).
- Monitor I&O. Report change in I&O ratio or pattern. Because most of drug is eliminated unchanged by kidneys, compromised function
can lead to drug accumulation.
Patient & Family Education
- Report fever, sore mouth or throat, and unusual bleeding or bruising tendency to physician.
- Be aware that the general duration of therapy is 46 wk, but it may continue for several months.