Necessity of vancomycin trough concentrations to manage uncomplicated acute bacterial skin and skin structure infections: a laboratory stewardship analysis.

Abstract

Recent recommendations by the American Society of Health System Pharmacists and Infectious Disease Society of America have provided guidance regarding vancomycin dosing and monitoring in serious infections (including methicillin-resistant Staphylococcus aureus); however, trough monitoring for uncomplicated acute bacterial skin and skin structure infections (ABSSSI) were not addressed. Vancomycin use appears to lead to a low incidence of acute kidney injury with short durations and a low trough goal (10-15 mg/L). Nevertheless, clinical studies have found no difference in clinical outcomes for ABSSSI regardless of vancomycin level. Therefore, it can be posed whether trough monitoring is necessary in this patient population. This is a retrospective cohort study comparing vancomycin therapy duration for ABSSSI in adult, general medicine patients who received scheduled vancomycin with an initial creatinine clearance rate of ≥50 mL/minute and had at least one vancomycin trough. The objective of this study was to determine if vancomycin treatment duration differs for patients with ABSSSI with a sub-therapeutic vancomycin trough (ST; <10 mg/L) compared with therapeutic trough (TT; ≥10 mg/L). There were 39 (67.2%) patients with ST compared with 19 (32.8%) with TT. A similar median vancomycin treatment duration for ST (48.25 hours) and TT (59.5 hours; p=0.65) was found. There was no statistical difference for hospital duration, time from last trough to vancomycin discontinuation, or incidence of acute kidney injury (p>0.05 for all). Patients with ST and TT had similar vancomycin durations and clinical outcomes. It may be prudent for institutions to address vancomycin trough laboratory stewardship and associated costs.