Flucytosine
Flucytosine (Ancobon)
Flucytosine
(flew- SYE-toe-seen)
Pregnancy Category: C Ancobon (Rx)

Classification: Antibiotic, antifungal

Action/Kinetics: Appears to penetrate the fungal cell membrane and, after metabolism, acts as an antimetabolite interfering with nucleic acid and protein synthesis. Less toxic than amphotericin B. Well absorbed from the GI tract and distributed to the joints, aqueous humor, peritoneal and other body fluids and tissues. Peak plasma concentration: 2-6 hr. Therapeutic serum concentration: 20-25 mcg/mL. t 1/2: 2-5 hr, higher in presence of impaired renal function. Eighty percent to 90% of the drug is excreted unchanged in urine.

Uses: Serious systemic fungal infections by susceptible strains of Candida (e.g., endocarditis, septicemia, UTIs) or Cryptococcus (pulmonary or UTIs, meningitis, septicemia).

Contraindications: Hypersensitivity to drug. Lactation.

Special Concerns: Safety and effectiveness have not been determined in children. Use with extreme caution in clients with kidney disease or history of bone marrow depression. The bone marrow depressant effects may cause an increased incidence of microbial infection, gingival bleeding, and delayed healing.

Side Effects: GI: N&V;, diarrhea, abdominal pain, dry mouth, anorexia, duodenal ulcer, GI hemorrhage, ulcerative colitis. Hematologic: Anemia, leukopenia, thrombocytopenia, aplastic anemia, agranulocytosis pancytopenia, eosinophilia. CNS: Headache, vertigo, confusion, sedation, hallucinations, paresthesia, parkinsonism, psychosis, pyrexia. Hepatic: Hepatic dysfunction, jaundice, elevation of hepatic enzymes, increase in bilirubin. GU: Increase in BUN and creatinine, azotemia, crystalluria, renal failure. Respiratory: Chest pain, dyspnea, respiratory arrest. Dermatologic: Pruritus, rash, urticaria, photosensitivity. Other: Ataxia, hearing loss, peripheral neuropathy, weakness, hypoglycemia, fatigue, cardiac arrest hypokalemia.

Overdose Management: Symptoms (serum levels > 100 mcg/mL): N&V;, diarrhea, leukopenia, thrombocytopenia, hepatitis. Treatment: Prompt induction of vomiting or gastric lavage. Adequate fluid intake (by IV if necessary). Monitor blood, liver, and kidney parameters frequently. Hemodialysis will quickly decrease serum levels.

Drug Interactions: Amphotericin B / Effect/toxicity of flucytosine R/T kidney impairment Cytosine / Inactivates antifungal effect of flucytosine

How Supplied: Capsule: 250 mg, 500 mg

Dosage
?Capsules
Adult and children: 50-150 mg/kg/day in four divided doses. Use lower doses in renal impairment.