Risk Factors for Vancomycin-Induced Nephrotoxicity and Kidney Prognosis in Patients Aged 75 Years and Older: A Retrospective Study.

Introduction: Whether risk factors for vancomycin-induced nephrotoxicity (VIN) development reported in recent years are also risk factors in the older population has not yet been fully investigated. This study aimed to investigate the risk factors for VIN development in the older population and to examine factors influencing kidney prognosis after VIN development.

Methods: A total of 468 patients aged ≥ 75 years were included in this study. Factors related to VIN onset in older adults were examined through logistic regression analysis.

Results: A total of 40 patients (8.5%) with VIN were identified. Univariate analysis revealed significant differences in body mass index (BMI), combined use of tazobactam/piperacillin (T/P), and intensive care unit admission between the VIN and non-VIN groups (P = 0.042, 0.005, and 0.040, respectively). Multivariate analysis identified the combined use of T/P as a factor related to VIN. In patients aged 85 years or older, the concomitant use of T/P and intensive care unit (ICU) admission were identified as factors related to VIN. Compared with the VIN recovery group, the nonrecovery group had a longer time to VIN onset and a higher proportion of patients on concomitant diuretics.

Conclusions: This study revealed that the combined use of T/P and ICU admission were risk factors for VIN in older individuals. Additionally, the time until VIN onset and the concomitant use of diuretics may affect the kidney prognosis of older patients who develop VIN. When administering vancomycin to older patients, it is necessary to eliminate or be cautious of these factors in relation to VIN development and kidney prognosis.