Adults

Loading dose: 400 mg every 12 hours for 2 doses. Maintenance dose: 200 mg every 12 hours. For 50 mg, dosage adjustments will be specific to the condition and may require higher frequency or multiple tablets.

Elderly

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

Renal_impairment

No dosage adjustment is necessary for oral voriconazole in patients with mild to severe renal impairment. However, the accumulation of the intravenous vehicle (SBECD) can be an issue, not applicable to oral tablets.

Onset

Within 1-2 hours for therapeutic levels.

Excretion

Less than 2% of the dose is excreted unchanged in urine. The majority is eliminated as metabolites through both renal and fecal routes.

Half life

Dose-dependent; approximately 6 hours at therapeutic doses, but can increase with higher doses due to non-linear kinetics.

Absorption

Rapid and almost complete absorption after oral administration, with peak plasma concentrations reached within 1-2 hours. Bioavailability is approximately 90%.

Metabolism

Extensively metabolized by hepatic cytochrome P450 enzymes, primarily CYP2C19, but also CYP2C9 and CYP3A4. Significant inter-individual variability due to CYP2C19 polymorphism.

Warfarin

Increases warfarin's anticoagulant effect. Monitor INR and adjust warfarin dose.

Phenytoin

Significantly decreases voriconazole levels and increases phenytoin levels. Monitor phenytoin levels and adjust voriconazole dose.

Omeprazole

Increases omeprazole exposure and voriconazole levels. Reduce omeprazole dose.

Cyclosporine, Tacrolimus, Sirolimus

Increases levels of these immunosuppressants. Reduce dose of immunosuppressant and monitor levels.