CYP2C19 and Hepatic failure: Moreover, the “VRZ personalized dosing guideline” strongly recommends Ctrough monitoring for patients with hepatic insufficiency, those co-administering drugs that affect VRZ pharmacokinetics, patients with CYP2C19 gene mutations, patients experiencing VRZ-related adverse events or suboptimal treatment efficacy, and critically ill patients with life-threatening fungal infections (Chen et al., 2018).