2026 Eastern States Conference

Evaluation of AUC vs. Trough-Based Vancomycin Dosing in the Outpatient Setting
Lauren Yates, PharmD; Adam Archer, PharmD, BCIDP; SungHo Park, PharmD 
 
Learning Objective  
Audience members will be able to identify key benefits of area-the-under-curve-based vancomycin dosing in the home health setting.  

Background/Objective
The primary objective of this study was to evaluate the safety, efficacy, and utility of using Bayesian-software-assisted 24-hour area-the-under-curve (AUC24) monitoring to dose vancomycin compared to trough-based dosing in the home infusion setting.   

Methods  
This single-center, retrospective, quasi-experimental pre-post study included patients ≥18 years old who were discharged on ≥ 7 days on intravenous vancomycin and enrolled in our institutional outpatient parenteral antimicrobial therapy (OPAT) monitoring program. Exclusion criteria included outpatient labs delayed by more than 14 days at any point in therapy. The primary endpoint was the incidence of acute kidney injury (AKI), defined as ≥ 0.5 mg/dl or ≥ 50% increase in serum creatinine from baseline within 7 days. Efficacy endpoints include 90-day all-cause mortality, infection-related 30-day readmission, and change in antibiotic therapy due to clinical worsening. Utility endpoints include the number of labs collected during outpatient therapy. Data was collected via manual chart review and included baseline demographics, renal function, infection characteristics, concomitant nephrotoxic medications, and vancomycin regimen details.   

Results
This study found that AUC-based vancomycin monitoring significantly reduced the risk of nephrotoxicity in the outpatient setting. A total of 258 patients' encounters were screened with 158 meeting inclusion criteria, which yielded 79 patients in both the AUC and trough monitoring cohorts. Baseline characteristics were well matched between groups. AUC-guided dosing significantly reduced the rates of AKI compared to trough-based dosing (7.6% vs 24.1%), corresponding to a risk ratio of 0.32 (95% CI 0.13–0.75; p=0.005). The median number of labs per weeks of therapy was significantly reduced in the AUC arm (0.95 vs. 1.22, p<0.001), resulting in an average cost saving of $450 per week.    
 
Conclusion
This study observed a significant reduction in AKI with AUC-guided vancomycin therapeutic drug monitoring in the home health setting, supporting guideline recommendations favoring AUC over trough-based monitoring in a patient population with limited data. As outpatient lab monitoring is often limited, AUC-guided vancomycin monitoring may improve patient outcomes by reducing adverse effects leading to readmission or early vancomycin discontinuation.

Self Assessment Question: 
True or False: There was a significant reduction in acute kidney injury in AUC-monitored patients compared to traditional trough-based monitoring in the outpatient setting.