Vancomycin-induced acute kidney injury in older Chinese patients: a multicenter retrospective cohort study

Vancomycin-associated nephrotoxicity remains a major clinical concern, yet evidence in older patients is limited and largely derived from small single-center studies. This multicenter study aimed to evaluate the incidence, risk factors, and outcomes of vancomycin-induced acute kidney injury (VI-AKI).

In this retrospective cohort study, patients aged ≥ 65 years who received vancomycin at three tertiary hospitals in Shanghai between 2009 and 2024 were included. AKI was defined according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Multivariable logistic regression was performed to identify independent risk factors. The primary outcome was VI-AKI incidence; secondary outcomes included renal recovery and all-cause mortality. A predefined subgroup analysis assessed the association between vancomycin trough concentrations and VI-AKI in patients undergoing therapeutic drug monitoring (TDM).

Among 3,762 patients, VI-AKI occurred in 640 (17.0%). Independent risk factors included age > 75 years, heart failure, baseline renal insufficiency, multiple organ failure, hypoproteinemia, intensive care unit admission, sepsis, vancomycin dose > 2 g/day, and concomitant use of aminoglycosides or piperacillin-tazobactam (all P < 0.05). Complete renal recovery occurred in 21.9% of patients and was less likely in those with stage 3 AKI (OR 0.43, P = 0.012), while acetylcysteine use was associated with a higher likelihood of recovery (OR 2.42, P = 0.009). In the TDM subgroup (n = 433), VI-AKI incidence was 25.9%, and trough concentrations ≥ 17.3 mg/L were independently associated with increased risk (OR 3.02, P < 0.001).

VI-AKI is common in older adults receiving vancomycin and is associated with multiple clinical and treatment-related factors. The low rate of renal recovery underscores the need for early risk stratification and optimized therapeutic drug monitoring in this population.

This clinical trial was registered in the Chinese Clinical Trial Registry (ChiCTR) with the identifier ChiCTR2400094474 on 23 December 2024.