Voriconazole

C. diff Risk

Low

Oral Bioavailability

NA

Approximate Cost

IV-$300 PO-$100

Spectrum Of Activity

Dosing

IV formulation contains sulfobutyl ether beta-cyclodextrin (SBECD) which may accumulate in renal insufficiency.

Renally cleared, requires dosage adjustment with changes in renal function.

Consult a pharmacist for renal dosing.

Adjust dose in hepatic impairment

In most patients, oral therapy has not been recommended as initial therapy for treatment; it has been recommended to convert parenteral to oral therapy only after significant clinical improvement has been observed
In pediatric patients <12 years, bioequivalence between the oral tablet and suspension has not been determined; due to possible shortened gastric transit time in infants and children, absorption of tablets may be different than adults; it is recommended that infants and children <12 years only receive oral suspension formulation.

General Information

Common Usage

Candida infections both mucocutaneous and invasive - i.e. Candidemia

Antifungal prophylaxis in immunocompromised

Drug Monitoring

Therapeutic drug monitoring may be helpful to ensure adequate concentrations and exclude toxicity (discuss with ID)

Monitor QTc interval in patients at elevated risk

Monitor hepatic profile

Adverse Effects

QTc prolongation

Hepatic enzyme abnormalities

Rash - up to 20%

GI upset.

Visual disturbances commonly associated with treatment, usually reversible with duration of use < 28 days.

Major Interactions

Many via CYP450- suggest review interactions with pharmacist.

Risk when combining with other QTc prolonging agents

Pharmacology

Antimicrobial class: Triazole antifungal, second generation

Average serum half life: Variable and dose dependent.

Route of Elimination: Urine (<2% as unchanged drug)