TDM should be initiated early when administering VRZ, and if steady-state Ctrough falls below the lower limit or if treatment efficacy is suboptimal, dosage adjustments should be made according to the dose adjustment scheme outlined in the “VRZ personalized dosing guideline.” Additionally, the CYP2C19 gene phenotype plays a crucial role in determining VRZ dosage in patients with hepatic insufficiency. Here, CYP2C19 is linked to Hepatic failure.