Vancomycin Dosing Considerations in a Real-World Cohort of Obese and Extremely Obese Patients

Study Objective To compare the effects of empiric vancomycin dosing regimens on attainment of optimal target trough concentrations in obese (body mass index [BMI] 30–40 kg/m2) and extremely obese (BMI ≥ 40 kg/m2) patients. Design Retrospective cohort study. Data Source National Veterans Affairs standardized databases. Patients A total of 263 obese and 71 extremely obese (actual body weight range 72–244 kg in both groups) inpatients from all Veterans Affairs facilities nationally who had suspected methicillin‐resistant Staphylococcus aureus pneumonia and were treated with vancomycin between 2002 and 2012. Measurements and Main Results Patients with steady‐state trough concentrations (measured ≤ 2 hours before the next vancomycin dose) and no evidence of acute kidney injury before vancomycin initiation were included. Logistic regression models were used to measure the effect of various vancomycin dosing regimens on attainment of optimal target trough concentrations (15–20 mg/L). The mean total daily vancomycin dose was lower in obese versus extremely obese patients (2005 ± 736 vs 2306 ± 934 mg, p