Voriconazole is a potent antifungal drug prescribed for severe fungal infections. It is particularly effective against infections caused by Aspergillus species, Candida species, and other less common fungal pathogens. Available in both oral and IV forms for flexible administration.
Key Uses:
- Aspergillosis: It is often the first-line treatment for invasive aspergillosis.
- Candidiasis: It is used for invasive candidiasis, including cases resistant to other antifungal agents.
- Other Fungal Infections: It may also be used for infections caused by Scedosporium and Fusarium species.
Mechanism of Action:
Voriconazole targets ergosterol synthesis, weakening the fungal cell membrane. This disruption leads to increased cellular permeability and eventual cell death.
Dosage and Administration:
- Oral: Typically taken on an empty stomach to enhance absorption.
- IV: Administered by healthcare professionals, usually in a hospital setting.
Common Side Effects:
- Visual disturbances: (e.g., blurred vision, photophobia)
- Liver enzyme elevations
- Skin rash
- Nausea and vomiting
- Headache
Serious Side Effects:
- Hepatotoxicity (liver damage)
- QT prolongation (a heart rhythm condition)
- Severe skin reactions (e.g., Stevens-Johnson syndrome)
Drug Interactions:
Voriconazole has numerous drug interactions due to its metabolism via the cytochrome P450 enzyme system. Notable interactions include:
- Rifampin: Decreases voriconazole levels.
- Phenytoin: Requires dose adjustment of voriconazole.
- Warfarin: Increased risk of bleeding.
- Cyclosporine: Increased levels of cyclosporine.
Monitoring:
- Liver function tests (LFTs) should be monitored regularly.
- Therapeutic drug monitoring (TDM) may be necessary to ensure appropriate drug levels, especially in patients with variable metabolism or those taking interacting medications.
Contraindications:
- Hypersensitivity to voriconazole or any of its components.
- Concurrent use with CYP3A4-metabolized drugs (e.g., sirolimus, quinidine).
Special Populations:
- Pregnancy: Category D; should be used only if the potential benefit justifies the potential risk to the fetus.
- Lactation: Not recommended during breastfeeding.
- Pediatric and Geriatric Patients: Dose adjustments may be necessary.
Voriconazole is a potent antifungal agent with a broad spectrum of activity, but its use requires careful monitoring and management of potential side effects and drug interactions. Always talk to a healthcare professional for personalized recommendations.