AUC-Based Vancomycin Monitoring Does Not Result in Higher Total Costs for MRSA Bacteremia

With updated vancomycin monitoring guidelines expected to be released in the near future, clinicians anticipate that these updated guidelines will recommend area under the curve (AUC)-based monitoring in place of trough-based monitoring for methicillin-resistant Staphylococcus aureus (MRSA) infections.

AUC can be estimated through the use of 2 steady state serum concentrations and the use of pharmacokinetic equations or by Bayesian modeling. Some institutions, including SUNY Upstate University Hospital in Syracuse, New York, use 2-point pharmacokinetics.

While evidence has suggested improved clinical outcomes with AUC, the cost of the monitoring may influence the decision to implement AUC-based monitoring. Additionally, data comparing the costs of AUC-based monitoring versus trough-based monitoring are lacking.

Therefore, a team of investigators from the Department of Pharmacy devised a study with the intention of comparing the total vancomycin drug and monitoring cost for patients with MRSA bacteremia who received trough- or AUC-based monitoring. The findings of the study were presented in a poster session at the Making a Difference in Infectious Diseases 2019 (MAD-ID) annual meeting.

In an exclusive interview, Contagion® spoke with the presenter of the poster Mario V. Beccari, PharmD, BCPS, AAHIVP, PGY2 Infectious Diseases Pharmacy Resident at Upstate University Hospital.

The team conducted a retrospective cohort study for patients treated for MRSA bacteremia between May 1, 2013 through December 31, 2018 at SUNY Upstate University Hospital. The study included an 8-month washout period between trough- and AUC-based monitoring.

According to the investigators, the primary outcome was the aggregate cost of vancomycin therapy, comprised of costs for sample collection, analysis, result interpretation, and cost of total administered vancomycin dose throughout the patient’s hospital stay. All of the costs were expressed as cost incurred to the hospital.

In total, 52 patients met inclusion criteria and 26 were placed in the trough-based group and 26 were placed into the AUC-based group. The median total vancomycin drug and monitoring cost was $316.79 (range: 253.36-$520.96) in the trough-based group compared to $338.14 (range: $235.07-$601.05) in the AUC-based group (P=0.687).

Based on these results, the investigators conclude that AUC-based vancomycin monitoring does not result in higher total drug and monitoring cost compared to trough-based monitoring for patients with MRSA bacteremia.

The poster “Cost Comparison of Trough- versus AUC-based Vancomycin Monitoring for MRSA Bacteremia,” was presented on Thursday, May 9, 2019 at MAD-ID 2019 in Orlando, Florida.