Implementing AUC Monitoring in a Pharmacist-Managed Vancomycin Dosing Protocol: A Retrospective Cohort Study

Background Consensus guidelines on the therapeutic drug monitoring of vancomycin published in 2020 recognize that using the calculated area-under-the-curve (AUC) to guide dosing maximizes clinical efficacy and minimizes risk when compared to traditional trough-based dosing. The purpose of this study was to determine whether AUC monitoring results in reduced acute kidney injury (AKI) rates in adult patients receiving vancomycin for all indications. Methods In this study, patients 18 years or older who received pharmacist-managed vancomycin therapy were selected using pharmacy surveillance software from 2 timeframes. Patients were excluded if they received less than 48 hours of therapy or had unstable renal function or hemodialysis at baseline. The primary outcome measured was the incidence of AKI in each group of patients. Results Data were collected for 121 patients in each group. Concomitant nephrotoxins used in each group, as well as the sources of infection, were similar between groups. AUC monitoring did not result in a significant decrease in AKI rate (16.5% in AUC group, 14.9% in trough group; P = .61). However, patients who received AUC monitoring were more likely to be therapeutic at first follow-up compared to the trough monitoring group (43.2% in AUC group, 33.9% in trough group; P = .03). AUC monitoring also resulted in lower trough levels and total daily doses, with no difference in mortality or length of stay. Conclusion AUC monitoring did not result in an observed decrease in AKI rate. Despite this, the AUC monitoring protocol was effective at reaching the goal AUC of 400-600 mg*hour/L and did not increase mortality or length of stay.