Ancobon

Ancobon,

a trademark for an antifungal (flucytosine).

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flucytosine

Ancobon, Ancotil (UK)

Pharmacologic class: Fluorinated pyrimidine analog

Therapeutic class: Antifungal

Pregnancy risk category C

FDA Boxed Warning

• Use with extreme caution in renal impairment. Closely monitor hematologic, renal, and hepatic status of all patients. Review instructions thoroughly before administration.

Action

Unclear. Thought to interfere with protein synthesis in cells of susceptible fungi after conversion to fluorouracil.

Availability

Capsules: 250 mg, 500 mg

⊘Indications and dosages

➣ Severe fungal infections caused by susceptible strains of Candida species (including septicemia, endocarditis, urinary tract infections [UTIs]), and pulmonary infections) and Cryptococcus species (including meningitis, pulmonary infections, and UTIs)

Adults: 50 to 150 mg/kg P.O. daily in four equally divided doses q 6 hours

Dosage adjustment

• Renal impairment (glomerular filtration rate below 50 ml/minute)

Off-label uses

• Chromomycosis

Contraindications

• Hypersensitivity to drug or other antifungals

Precautions

Use cautiously in:
• renal impairment, underlying hepatic disease, bone marrow depression
• pregnant or breastfeeding patients
• children (safety not established).

Administration

• Give capsules a few at a time over 15 minutes to minimize nausea and vomiting.
• Know that drug is rarely used alone. Expect to give another antifungal or amphotericin B concurrently.

Route	Onset	Peak	Duration
P.O.	Variable	2 hr	10-12 hr

Adverse reactions

CNS: headache, dizziness, confusion, hallucinations, vertigo, psychosis, ataxia, paresthesia, parkinsonism, peripheral neuropathy

CV: chest pain, cardiac arrest

EENT: hearing loss

GI: nausea, vomiting, diarrhea, dyspepsia, ulcerative colitis, abdominal discomfort, anorexia, duodenal ulcer, hemorrhage

GU: azotemia, crystalluria, renal failure

Hematologic: eosinophilia, anemia, leukopenia, aplastic anemia, thrombocytopenia, bone marrow depression, agranulocytosis

Hepatic: jaundice

Metabolic: hypokalemia, hypoglycemia

Respiratory: dyspnea, respiratory arrest

Skin: rash, pruritus, urticaria, photosensitivity

Interactions

Drug-drug. Amphotericin B: synergistic effects, increased risk of toxicity

Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, bilirubin, gamma-glutamyltransferase: increased levels

Glucose, granulocytes, hemoglobin, platelets, potassium, white blood cells: decreased levels

Patient monitoring

• Monitor kidney and liver function test results.
• Carefully monitor blood glucose level and hematologic test results.
☞ Assess for serious cardiovascular, renal, respiratory, and hematologic adverse reactions.
• Evaluate electrolyte levels, particularly potassium.
• Assess for signs and symptoms of bleeding.

Patient teaching

• Advise patient to take capsules over 15-minute period to reduce GI upset.
☞ Instruct patient to immediately report unusual bleeding or bruising.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
• Instruct patient to minimize GI upset by eating frequent, small servings of food and drinking adequate fluids.
• Advise female patient to inform prescriber if she is pregnant or breastfeeding.
• Tell patient he'll undergo regular blood testing during therapy.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.