The association of high Vancomycin trough concentration with acute kidney injury during combination therapy of Piperacillin/Tazobactam and Vancomycin

BACKGROUND: Co-administration of Piperacillin/Tazobactam (PIPC/TAZ) and Vancomycin (VCM) as an antibiotic therapy for severe infectious diseases increases the risk of nephrotoxicity. We retrospectively investigated the utility of monitoring VCM trough concentration in early stage of developing acute kidney injury (AKI) on this combination therapy. METHODS: We enrolled all infectious disease patients who were managed with concurrent PIPC/TAZ and VCM. The record of dosage and the administration interval of each antibiotic and its clinical parameters, as well as the VCM trough concentrations, blood culture for bacteria, and serum creatinine values, were collected. VCM trough concentration was measured during the initial 48–72 h of VCM administration. Nephrotoxicity was evaluated as the degree of AKI. RESULTS: A total of 47 patients fulfilling the criteria were registered, and AKI developed in 10 patients. There was no statistical difference between the AKI and non-AKI groups with regard to age, height, weight, basal creatinine level, body surface area, body mass index, PIPC/TAZ dose, VCM dose, gender, artificial management, and death within around 30 days. The VCM trough level was increased significantly in the AKI group (mean [standard deviation {SD}]: 25.9 [7.8] μg/mL) compared to that in the non-AKI group (mean [SD]: 15.7 [6.9] μg/mL) (p = 0.003). During the clinical course, renal function returned to normal levels in three out of four AKI stage 2 patients, whereas only partial recovery was achieved in all AKI stage 3 patients. CONCLUSIONS: A high VCM trough concentration may have an influence on the occurrence of AKI during combination therapy of PIPC/TAZ and VCM. Careful monitoring of VCM trough concentration will be required to prevent AKI progression.