Implementation of vancomycin AUC/MIC dosing vs traditional trough dosing and incidence of acute kidney injury at a rural community hospital

Abstract Purpose Vancomycin treats methicillin-resistant Staphylococcus aureus infections in hospitalized patients, yet nephrotoxicity is a major risk. Dosing based on the ratio of vancomycin 24-hour area under the curve to minimum inhibitory concentration (AUC/MIC) is preferred over a trough-only vancomycin dosing approach to minimize the risk of acute kidney injury (AKI). This study compares the safety of AUC/MIC-guided and trough-only vancomycin dosing at a 255-bed hospital. Methods A retrospective cohort study of adult patients with stable renal function who received at least 3 days of intravenous vancomycin via either AUC/MIC or trough-only dosing was conducted. The primary outcome was AKI occurrence during treatment. Secondary outcomes included the frequencies of therapeutic, subtherapeutic, and supratherapeutic vancomycin troughs. Relative risk calculations were performed for all outcomes. Results 600 patients from the trough-only group and 561 patients from the AUC/MIC group were included. 121 patients from the trough-only group and 87 patients from the AUC/MIC group experienced AKI during treatment (relative risk [RR], 0.769; 95% CI, 0.599-0.988; P = 0.0397). Compared with the trough-only group, the AUC/MIC group was significantly less likely to have supratherapeutic troughs (RR, 0.703; 95% CI, 0.611-0.809; P < 0.0001) and significantly more likely to have therapeutic troughs (RR, 1.14; 95% CI, 1.069-1.211; P < 0.0001), with no significant between-group difference in subtherapeutic troughs (RR, 1.03; 95% CI, 0.854-1.25; P = 0.74). Conclusion AUC/MIC dosing was associated with significantly lower risk of AKI, a lower risk of supratherapeutic trough levels, and a higher risk of therapeutic trough levels, with no significant difference in subtherapeutic troughs when compared to trough-only dosing. Limitations of this study included its retrospective nature and reliance on manual chart review.