Reviewed by Cindy Noyes, MD, University of Vermont Medical Center, Burlington, VT
Bottom line: Pharmacist-led AUC monitoring can occur in OPAT safely and may be associated with fewer episodes of nephrotoxicity.
Gillet and colleagues conducted a single center, quasi experimental, interrupted time series study at a large academic medical center from 9/2019 through 3/2023 to evaluate the safety and efficacy of area under the curve (AUC) monitoring with use of Bayesian modeling compared to standard of care trough-based monitoring for patients receiving intravenous vancomycin in the outpatient setting (OPAT). All patients referred to the OPAT program receiving vancomycin were screened for inclusion. Patients were excluded if receiving renal replacement therapy, enrolled for <72 hours, had fewer than 2 vancomycin serum concentrations, if there were no laboratory samples for >14 days or if the infectious disease (ID) clinician opted out. The OPAT program included 1 ID clinician, 1 nurse practitioner, 3 registered nurses, and 1 administrative assistant. Inpatient pharmacists optimized vancomycin dosing prior to patient discharge using AUC monitoring. During OPAT AUC monitoring, the goal AUC was 400-600 mg*hr/L and dosing managed with recommendations from pharmacy, while during trough goal monitoring, the ID clinician set the goals, generally between 10-20 mg/L. The primary safety outcome was nephrotoxicity, defined by a >0.5 mg/dL or >50% increase in serum creatinine during OPAT vancomycin therapy. Secondary efficacy was a 90 day all-cause mortality and all-cause hospital readmissions. There were 63 patients in AUC group, 60 patients in trough-based group. Characteristics were mostly similar though there were a higher number of patients receiving vancomycin for bone and joint and Staphylococcus aureus infections during periods of AUC monitoring, and higher rates of obesity during trough-based monitoring. Nephrotoxicity occurred in 4 of 63 (6.3%) of patients in the AUC group vs 14 of 60 (23%) in trough-monitoring group, which was statistically significant. Additionally, there were fewer unusable vancomycin concentrations in AUC group, fewer episodes of vancomycin discontinuation in the AUC group and no difference in all-cause mortality at 90 days or with re-admissions.
Reference: Gillet E, et al. Implementation of a pharmacist-driven vancomycin area under the concentration-time curve monitoring program using Bayesian modeling in outpatient parenteral antimicrobioal therapy. OFID. October 2024. https://doi.org/10.1093/ofid/0fae600