Adults

Oral: Loading dose of 400 mg every 12 hours for 2 doses, followed by a maintenance dose of 200 mg every 12 hours. Doses may be increased to 300 mg every 12 hours if response is inadequate.

Elderly

No dosage adjustment required based on age, but caution is advised due to potential for decreased hepatic and renal function.

Renal_impairment

No dosage adjustment required for oral administration. Monitor serum creatinine levels. For IV administration, adjust dosage due to accumulation of the intravenous vehicle (SBECD).

Onset

Variable, typically within 1-2 hours for peak plasma levels.

Excretion

Primarily through hepatic metabolism with <2% of the dose excreted unchanged in urine. Less than 5% excreted in feces.

Half life

Dose-dependent, with a non-linear pharmacokinetic profile. Terminal half-life ranges from 6 hours (at lower doses) to highly variable at higher doses.

Absorption

Rapid and nearly complete absorption orally, with absolute bioavailability of approximately 90%. Peak plasma concentrations achieved in 1-2 hours.

Metabolism

Primarily hepatic metabolism via cytochrome P450 enzymes (CYP2C19, CYP2C9, and CYP3A4). CYP2C19 is a major enzyme in its metabolism.

Warfarin

Voriconazole can prolong prothrombin time and increase INR. Close monitoring of INR is essential.

Phenytoin

Voriconazole significantly increases phenytoin levels. Phenytoin dose reduction and monitoring are required.

Rifampicin

Significantly reduces voriconazole plasma levels, concurrent use is contraindicated.

Cyclosporine

Voriconazole increases cyclosporine plasma concentrations. Cyclosporine dosage reduction and monitoring are required.