Voriconazole: Price, Dosage & Where to Buy

Voriconazole is an azole antifungal medicine used mainly for serious invasive fungal infections. It is prescribed for conditions including invasive aspergillosis, candidemia and other deep tissue Candida infections, and serious infections caused by Scedosporium or Fusarium species. Voriconazole is a prescription medicine in the United Kingdom, and generic versions have been available since 2010-04-22.

Voriconazole belongs to the azole antifungal group. Fungal cells need a substance called ergosterol to build and maintain their cell membrane. Voriconazole blocks fungal enzymes involved in making ergosterol, particularly enzymes in the cytochrome P450 system.

With less ergosterol available, the fungal cell membrane becomes abnormal and cannot function normally. This limits the growth and survival of susceptible fungi.

Voriconazole is active against several clinically important moulds and yeasts, including Aspergillus, Candida, Scedosporium and Fusarium species. Its effects and blood concentrations can be influenced by other medicines because voriconazole is metabolised by CYP2C19, CYP2C9 and CYP3A4, and also affects the handling of medicines processed by these enzymes.

Voriconazole is used to treat invasive aspergillosis, a serious infection caused by Aspergillus fungi. It is also used for candidemia in non-neutropenic patients and other deep tissue Candida infections, including disseminated skin infections and infections affecting the abdomen, kidney, bladder wall or wounds.

The medicine is also indicated for oesophageal candidiasis. In adults and children aged 2 years and older, it can treat serious fungal infections caused by Scedosporium apiospermum and Fusarium species, including Fusarium solani, when other therapy has not been tolerated or has not worked. Fungal culture and other relevant laboratory studies should be obtained before treatment where possible, so therapy can be adjusted when the causative organism is identified.

The label lists oral tablets and oral suspension, as well as intravenous infusion products. The label lists tablet strengths of 50 mg and 200 mg, an oral suspension strength of 40 mg/mL, and intravenous products at 10 mg/mL.

The usual starting dose is 6 mg/kg every 12 hours for the first 24 hours for invasive aspergillosis, followed by 4 mg/kg every 12 hours intravenously or 200 mg every 12 hours orally. The label lists 5 mL every 12 hours as the corresponding adult oral suspension maintenance dose. The label lists 3-4 mg/kg every 12 hours intravenously for candidemia and other deep tissue Candida infections, with 200 mg every 12 hours orally or 5 mL every 12 hours as alternatives.

The label lists 200 mg every 12 hours orally or 5 mL every 12 hours for oesophageal candidiasis. Adult patients weighing less than 40 kg should receive half of the oral maintenance dose. Tablets are administered at least one hour before or after a meal.

Store voriconazole tablets at 20° to 25°C (68° to 77°F), as directed on the label. Keep the medicine in its original packaging, protected from moisture and out of reach of children to maintain quality.

A missed dose can reduce the amount of antifungal medicine in the body and may affect treatment of a serious infection. General pharmacy practice is to follow the prescribed schedule and seek advice from a doctor or pharmacist if a dose is missed, particularly when treatment is being given for an invasive infection. A double dose should not be used to compensate unless specifically directed by a healthcare professional.

Voriconazole can cause fetal harm when administered during pregnancy, and there are no available data on its use in pregnant women. Animal studies found fetal malformations and fetal toxicity.

Females of reproductive potential are advised to use effective contraception during treatment. No data are available about voriconazole in human milk, effects on a breastfed infant or effects on milk production; discuss treatment and breastfeeding with a doctor or pharmacist.