Study of Obese Patients Comparing Two Vancomycin Loading Dose Regimens

Obesity alters the movement through the body of several antibiotics, including vancomycin.
Based on literature to date, total body weight should be used to determine dosages and
shorter dosing intervals may be needed. However, hospitals have different approaches to
managing vancomycin in this patient population. The most common example is not exceeding a
dose of 2,000mg of vancomycin at one time in these patients. However, some institutions
including the Charleston Area Medical Center do not have a set maximum one time dose. To
date, a study has not been done comparing two different dosing regimens in obese patients to
determine if having a maximum dose cap is beneficial.

This research study is attempting to add to the limited existing body of literature regarding
vancomycin dosing in obese patients. The investigators hypothesize that optimizing the
initial or loading vancomycin dose that obese patients receive will decrease the time to
target concentrations. For this study, obese adult patients will be randomized to receive
either 1) a loading dose of 20 mg/kg with a maximum dose up to 2,000mg OR 2) a loading dose
of 20 mg/kg with a maximum dose of up to 4,000mg. The study's primary aim is to determine
differences in the time needed to achieve target vancomycin concentrations and the occurrence
of adverse events.