Voriconazole

Key facts

• Voriconazole is a triazole antifungal used for serious, potentially life-threatening fungal infections, including invasive aspergillosis and candida in the bloodstream. It is taken as tablets, oral suspension, or an intravenous infusion.
• Liver toxicity is common and can be severe. Liver function tests are checked before treatment starts and regularly throughout, and the drug is stopped if liver injury develops.
• Temporary visual disturbances, such as blurred vision, altered color perception, or light flashes, are very common shortly after each dose.
• Long-term voriconazole use increases the risk of skin cancer through sun sensitivity; strict sun protection and periodic skin checks are needed throughout treatment.

What voriconazole treats

Voriconazole treats invasive aspergillosis, candidemia in people without severely low white blood cell counts, esophageal candidiasis, and serious infections caused by Scedosporium and Fusarium species. It is not used for minor or superficial fungal infections such as ordinary skin or nail infections.

How voriconazole works

Voriconazole blocks a fungal enzyme needed to build ergosterol, an essential building block of the fungal cell membrane. Without enough ergosterol, the membrane becomes unstable and leaky, and the fungus cannot survive or multiply, allowing the infection to clear.

Before you take it

• Voriconazole must not be combined with rifampicin, carbamazepine, long-acting barbiturates, high-dose ritonavir, St John's wort, ergot alkaloids, sirolimus, certain statins, or drugs that prolong the QT interval; these combinations can cause treatment failure or dangerous interactions.
• Avoid voriconazole in pregnancy unless clearly necessary, as it can harm the developing fetus.
• Tell your prescriber about any liver disease or history of an irregular heart rhythm before starting.
• Ask your pharmacist to check your full medicine list, because voriconazole interacts with many common drugs.

Side effects

Common effects include visual disturbances, nausea, headache, rash, and mild elevation of liver enzymes.

Stop and seek urgent medical care for any of these:

• Yellowing of the skin or eyes, dark urine, or persistent nausea, which can signal liver injury.
• Severe or persistent visual changes, or hallucinations.
• Severe skin reactions, such as blistering or peeling.
• An irregular or unusually fast heartbeat.

Safety essentials

• Liver function tests are required before starting voriconazole and at regular intervals throughout treatment; stop the medicine and seek care for any sign of liver injury.
• Use sunscreen and avoid strong sun exposure throughout treatment. Long courses raise the risk of skin cancer, so periodic skin checks are recommended.
• Check for interacting medicines before starting; several common drugs are contraindicated with voriconazole.
• Report any new visual changes, especially at night or while driving.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.