How it is administered

Voriconazole can be given as a tablet, oral suspension, or intravenous (IV) infusion.

• Tablets: Available in 50 mg and 200 mg strengths, taken by mouth at least one hour before or after a meal.
• Oral Suspension: Reconstituted to 40 mg/mL, taken by mouth using the provided dispenser.
• IV Infusion: Provided as a lyophilized powder, reconstituted and diluted for infusion over 1 to 3 hours.

Dosing depends on age, weight, and the type of infection. For adults, a typical starting dose for invasive aspergillosis is a loading dose of 6 mg/kg every 12 hours for the first 24 hours, then a maintenance dose of 4 mg/kg IV every 12 hours or 200 mg orally every 12 hours. For pediatric patients, dosing is weight-based and may differ.

Patients with liver or kidney impairment may require dose adjustments. IV administration is generally avoided in patients with moderate to severe kidney impairment due to accumulation of the IV vehicle.

How it works

Voriconazole is an antifungal medication belonging to the azole class. It works by inhibiting an enzyme called fungal cytochrome P-450-dependent 14 alpha-lanosterol demethylation, which is crucial for the synthesis of ergosterol, an essential component of fungal cell membranes. By blocking this enzyme, voriconazole disrupts the production of ergosterol, leading to a weakened cell membrane and ultimately causing the death of the fungal cell.

This mechanism makes voriconazole effective against a range of serious fungal infections, including those caused by Aspergillus and Candida species. In the context of blood cancers such as Acute Myeloid Leukemia (AML), patients are often immunocompromised and at high risk for invasive fungal infections. Voriconazole is particularly valuable in treating invasive aspergillosis, a life-threatening infection that can occur in these patients. Its broad antifungal activity and ability to penetrate tissues make it a key option for managing these serious infections.

Who Should take it

Voriconazole is prescribed for adults and children (2 years and older) who have serious fungal infections, especially when these infections are invasive or resistant to other treatments.

For patients with blood cancers like Acute Myeloid Leukemia (AML), voriconazole is commonly used to treat or prevent invasive aspergillosis, a potentially fatal infection. It is also indicated for candidemia (a bloodstream infection caused by Candida), esophageal candidiasis, and serious infections caused by Scedosporium apiospermum and Fusarium species, particularly in those who cannot tolerate or have not responded to other antifungal therapies.

In the context of AML and other blood cancers, voriconazole is often used because these patients are at higher risk for severe fungal infections due to weakened immune systems from chemotherapy or stem cell transplantation.

Who should not take it

Voriconazole should not be used in patients who have a known allergy or hypersensitivity to voriconazole or any of its components.

It is also contraindicated in patients taking certain medications that can interact dangerously with voriconazole, such as pimozide, quinidine, sirolimus, rifampin, carbamazepine, long-acting barbiturates, St. John’s Wort, efavirenz (at standard doses), high-dose ritonavir, rifabutin, ergot alkaloids, naloxegol, tolvaptan, venetoclax (during ramp-up in CLL/SLL), lurasidone, and finerenone. These combinations can lead to serious side effects, loss of efficacy, or life-threatening heart rhythm disturbances.

Patients with hereditary galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption should not take voriconazole tablets due to the presence of lactose. Caution is also advised in patients with severe liver impairment, unless the benefits outweigh the risks.

Commonly used with

Voriconazole is often used alongside other medications in patients with blood cancers, especially those undergoing chemotherapy or stem cell transplantation. It may be used with:

• Antibacterial and antiviral agents to cover a broad range of infections in immunocompromised patients
• Immunosuppressive drugs (such as cyclosporine or tacrolimus) in transplant patients, though doses of these drugs may need to be adjusted due to interactions
• Supportive care medications, such as anti-nausea drugs or pain relievers

Because voriconazole interacts with many medications, your healthcare team will carefully review all your current medicines to avoid harmful interactions.

Commonly tested with

Voriconazole is frequently studied in combination with other antifungal agents or as part of multi-drug regimens in clinical trials for treating invasive fungal infections in immunocompromised patients, including those with AML.

It is often compared to or used after failure of other antifungals such as amphotericin B, fluconazole, or echinocandins. In clinical practice and studies, voriconazole may be tested alongside supportive therapies and in the context of various chemotherapy regimens to assess its effectiveness and safety in preventing or treating fungal infections in high-risk patients.