Does a Dosing Design Based on Plasma Drug Concentrations 3 Days after the Initiation of Oral Voriconazole Administration Improve Safety in Patients Receiving Oral Voriconazole?

Voriconazole (VRCZ) is a target drug for therapeutic drug monitoring because of its complex pharmacokinetics and narrow recommended therapeutic range of 1 – 4 μg/mL in Japanese patients. Recently, blood was recommended to be drawn early after VRCZ administration to prevent adverse events. However, there is a concern that if the dose is changed based on the trough value at which the steady-state is not reached, VRCZ plasma concentrations will be outside the therapeutic range. Therefore, we implemented a dosing design based on plasma drug concentrations on day 4 after VRCZ administration and examined its usefulness.