Steady state trough levels are achieved within 1 day when an IV loading dose is used and after approximately 5 days of oral or IV therapy without a loading dose.
Therapeutic range
Prophylaxis: trough >0.5 mcg/mL
Therapeutic range for treatment: trough 2.0-5.5 mcg/mL
Serum trough levels less than or equal to 1 mcg/mL are reported to be associated with lack of therapeutic response and serum trough levels >5.5 mcg/mL have been reported to be associated with reversible neurological adverse events and hepatotoxicity.
Co-administration of drugs that metabolically induce or inhibit CYP2C19, or other conditions that affect CYP2C19 may alter voriconazole metabolism.