1415. Implementation and Validation of a Vancomycin AUC/MIC Calculator and Dosing Protocol at a Large Community Hospital.
Session: Poster Abstract Session: PK/PD Studies
Friday, October 5, 2018
Room: S Poster Hall
Background:Current IDSA guidelines
recommend targeting a vancomycin trough between 15-20 mg/L to achieve an AUC/MIC
≥ 400, however, recent literature shows increased rates of nephrotoxicity
within this range and the target AUC/MIC ratio may be achieved with lower
troughs. We sought to determine if a vancomycin AUC-based dosing protocol and
spreadsheet-based calculator, using one-compartment population-based dosing and
2 steady-state serum levels, accurately predicted AUC/MIC ratio in patients
with moderate to severe Staphylococcus aureus infections.
Methods:A retrospective analysis of 60 adult patients treated with
vancomycin for culture-confirmed S. aureus was conducted. The primary
outcome was percent of patients who met the AUC/MIC goal of ≥ 400.
Secondary outcomes included: mean initial trough concentration in patients who
met the AUC/MIC goal compared with those who did not; correlation of two different
methods of AUC-estimation with the patient's actual AUC; percentage of patients
meeting AUC/MIC goal stratified by initial trough concentrations, age, weight,
and indication; and percentage of patients meeting the AUC goal stratified by
the same variables. Results were analyzed using descriptive statistics and
calculations were performed using SPSS.
Results: The median age (range) was 55 (22-86) and 52% were male.
Eighty-three percent of patients achieved an initial AUC/MIC ≥ 400,
including 93% with serum troughs between 10 - 14.9 mg/L. Patients who
met the AUC/MIC goal had an average trough of 13.5 mg/L, whereas those who did
not had an average trough of 7.8 mg/L (p<0.001).
AUC estimation using population pharmacokinetics was significantly correlated
with actual AUC (p = 0.011), however this was not a strong correlation (r =
0.340). Subgroup analysis based on age, weight, and indication identified areas
for improvement in the empiric dosing protocol at our institution.
Conclusion: Use of the vancomycin AUC-based dosing protocol and
calculator resulted in achievement of efficacy goal in the majority of
patients, including many with vancomycin troughs between 10-15 mg/L. More
accurate estimation of AUC and other pharmacokinetic variables using local
patient data is important for improving the reliability of vancomycin dosing
Megan Seddon, PharmD1, Kevin Scorgie, PharmD, BCPS2, Sara Kutner, PharmD2, Andre McMahon, PharmD2 and Jamie Kisgen, PharmD, BCPS (AQ-ID)2, (1)University of South Carolina and Palmetto Health, Columbia, SC, (2)Department of Pharmacy, Sarasota Memorial Health Care System, Sarasota, FL
None S. Kutner,
None A. McMahon,
None J. Kisgen,