Adults

Loading dose: 6 mg/kg every 12 hours for two doses. Maintenance dose: 4 mg/kg every 12 hours. Dosage should be adjusted based on therapeutic drug monitoring.

Elderly

No dosage adjustment required for elderly patients, but careful monitoring is advised due to potential age-related decrease in metabolism.

Renal_impairment

The intravenous formulation contains a sulfobutylether beta-cyclodextrin sodium (SBECD) vehicle, which is renally cleared. In patients with moderate to severe renal impairment (creatinine clearance < 50 mL/min), accumulation of SBECD can occur. Oral formulation is preferred if possible. If IV use is unavoidable, switch to oral as soon as possible and monitor renal function closely.

Onset

Rapid, typically within 1-2 hours of infusion.

Excretion

Approximately 80% of the dose is excreted in the urine as metabolites, with less than 5% as unchanged drug. Renal excretion of the cyclodextrin vehicle should be considered in patients with renal impairment.

Half life

Variable and dose-dependent, typically ranging from 6 to 8 hours but can be longer with higher doses due to non-linear kinetics.

Absorption

Following intravenous administration, voriderm is rapidly and extensively absorbed, achieving 100% bioavailability. Peak plasma concentrations are reached shortly after infusion.

Metabolism

Primarily metabolized in the liver by cytochrome P450 isoenzymes, particularly CYP2C19, CYP2C9, and CYP3A4. Extensive first-pass metabolism occurs.

Warfarin

Voriderm may increase warfarin levels, leading to increased prothrombin time and bleeding risk. Monitor INR closely.

Efavirenz

Co-administration results in significant drug interactions; contraindicated unless benefits outweigh risks and dose adjustments are made for both drugs.

Ritonavir

High doses of ritonavir (400 mg every 12 hours) significantly decrease voriconazole levels. Concomitant use is contraindicated. Lower doses (100 mg every 12 hours) may be used with caution and TDM.

Cyclosporine, Tacrolimus, Sirolimus

Voriderm can increase concentrations of these immunosuppressants. Reduce dose of immunosuppressant and monitor levels.

Statins (e.g., Lovastatin, Simvastatin)

Voriderm can increase statin levels, increasing risk of rhabdomyolysis. Consider dose reduction or discontinuation of statins.

Rifampicin, Carbamazepine, Phenobarbital

Strong inducers of CYP450, significantly decrease voriconazole plasma concentrations, leading to therapeutic failure. Concomitant use is contraindicated.