Therapeutic drug monitoring and safety of voriconazole in elderly patients

•The voriconazole trough concentration (VTC) was higher in elderly patients.•The proportion of patients with a VTC of >5 μg/mL was higher in elderly patients.•The procalcitonin concentration was associated with the VTC in elderly patients.•Procalcitonin concentrations of ≥1.31 ng/mL increased the incidence of a VTC of >5 μg/mL.•Voriconazole dose adjustment according to the procalcitonin concentration is necessary. Data on therapeutic drug monitoring of voriconazole in elderly patients are limited. Impaired liver function and an inflammatory state in elderly individuals are hypothesized to impact the voriconazole serum level. A total of 166 adult patients (317 trough concentrations) who underwent voriconazole therapeutic drug monitoring were enrolled. The voriconazole trough concentration, its associated covariates, and its correlation with adverse effects in 73 elderly (≥60 years) patients (116 trough concentrations) were analyzed and compared to those in 93 adult (