Voriconazole

C. diff Risk

Low

Oral Bioavailability

Excellent

Approximate Cost

Non-formulary.

Dosing

Hepatic

Mild to moderate (Child-Pugh class A or B)
Standard loading dose then reduce maintenance dose by 50%

Severe impairment (Child-Pugh class C)
Should only be used if benefit outweighs risk. Monitor closely for toxicity.

General Information

Unacceptable Uses

Non-formulary at MSH.

Common Usage

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

Antifungal prophylaxis in immunocompromised patients.

Drug Monitoring

Therapeutic drug monitoring may be helpful to ensure adequate concentrations and exclude toxicity (Discuss with ID). When voriconazole is taken concomitantly with other drugs, dose adjustment of voriconazole or the concomitant drug may be required due to drug interactions.

QTc interval in patients at elevated risk.

Monitor hepatic profile.

Adverse Effects

  • Infusion related effects: tachycardia, dyspnea, fever, flushing.

  • QTc prolongation

  • Hepatic enzyme abnormalities

  • Rash - up to 20%

  • Visual disturbance

  • Fluorosis

  • ¬†GI upset

Major Interactions

CYP450 interactions ++.

Other QTc prolonging agents.

Recommend review of pt medications due to high frequency of significant interactions.

Pharmacology

Antimicrobial class: Triazole antifungal, Second generation

Pregnancy category: D

Average serum half life: Variable, dose-dependent. Steady-state is achieved by day 3 when an IV loading dose is administered and between days 5 and 8 if no loading dose is used (Purkins 2003).

CSF penetration: Therapeutic

Lung penetration: Therapeutic

Urine penetration: Poor