Title
Evaluating Vancomycin AUC Monitoring in Adult Cystic Fibrosis Patients
Authors
Taylor J. Merritt, Carrie Tilton Callahan, Kelly Soyeong Ko, Cynthia Shin-Yee Tsai, Heidi King Berman, Nicole L. Metzger
Practice Site
Emory University Hospital
Objective
Audience members will be able to evaluate the impact of AUC-based vancomycin monitoring on therapeutic target attainment and safety outcomes compared with traditional trough-based monitoring in adult patients with cystic fibrosis (CF)
Background
Area under the curve (AUC)–based vancomycin monitoring is recommended to improve efficacy and reduce nephrotoxicity. However, evidence supporting its use in adult people with cystic fibrosis (PwCF) remains limited.
Methods
This single-center, retrospective observational study included hospitalized adults with CF who received intravenous vancomycin and at least one appropriately drawn vancomycin level. Patients were excluded if they were pediatric, pregnant, incarcerated, had unstable renal function, or did not have vancomycin for > 48 hours. Encounters were grouped based on strategy: AUC or trough-based monitoring. Therapeutic targets were defined as: AUC of 400–600 mg·hr/L or trough of 15–20 mg/dL. Primary outcome was the proportion of encounters achieving therapeutic targets at first appropriate level. Secondary outcomes included time to therapeutic target attainment, number of regimen adjustments, length of hospital stay, and incidence of acute kidney injury. An exploratory analysis was conducted by reclassifying patients in the trough-based group who met institutional AUC-dosing criteria and assessing whether therapeutic targets would have been achieved when using an institutional AUC calculator.
Results
A total of 43 encounters representing 27 patients met inclusion criteria, with 16 encounters in the AUC-based group and 27 in the trough-based group. Therapeutic exposure targets at first level draw were achieved in 37.5% of AUC-monitored encounters compared to 14.8% of trough-monitored (p-value 0.14). Mean time to therapeutic target attainment was similar between groups, and no cases of acute kidney injury occurred in the AUC group compared to 7.4% in the trough-based group. Length of hospital stay and number of vancomycin levels collected were comparable between strategies. In the exploratory analysis, patients regrouped from trough to AUC demonstrated 48.3% therapeutic targets at initial draw compared to 0% in the trough-based group.
Conclusions
AUC-based vancomycin monitoring did not demonstrate a statistically significant improvement over trough-based monitoring in adults with cystic fibrosis; however, a trend toward improved therapeutic target attainment and no increase in nephrotoxicity was observed. These findings support consideration of AUC-based monitoring in this population and add to the limited data available for adult patients with cystic fibrosis.
Self-Assessment Question
Which statement best reflects the findings from this study?
A) AUC-based monitoring significantly reduced AKI in PwCF
B) AUC-based monitoring significantly improved target attainment
C) Trough-based monitoring resulted in fewer regimen changes
D) AUC-based monitoring demonstrated a trend toward improved target attainment without increasing AKI
Contact Email
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