Impact of Weight Based Dosing Guidelines on Vancomycin Dosing and Trough Levels Including in Obese Patients
Background: In 2009, the American Society of Health System
Pharmacists, Infectious Diseases Society of America, Society of the Infectious
Methods: A retrospective review was done on patients at an acute care, university-affiliated, community hospital whoreceived intravenous vancomycin for suspected/documented infections before and after implementing the 2009 guidelines. Before 2009, patient received vancomycin, 1 gm every 12 hrs. After the guidelines, patientswere dosed on actual body weight (ABW), 15-20mg/kg, or 25-30mg/kg in seriously ill patients, every 8-12 hrs. We compared the frequency of therapeutic troughs, nephrotoxicity and trough group levels stratified by Body Mass Index (BMI).
Results: There were no significant differences in therapeutic troughs and nephrotoxicity.Adjusted for BMI, there was a significant difference in trough levels between the two groups, p=0.0109. However, a large number of patients in the conventionally-dosed group were excluded due to inconsistent doses. In the ABW-dosed group, there was a high number of high trough levels in 48% of patients with BMIs >35, p=0.005
Conclusion: Obese patients may require an alternate dosing strategy asthe ABW-dosing based on the 2009 national guidelines resulted in supra-therapeutic levels in patients with high BMIs. Implementing guidelines-based monitoring resulted in more consistent and appropriately drawn trough levels.
Conclusions: Obese patients may require an alternate dosing strategy as the ABW dosing based on the 2009 national guidelines resulted in supra-therapeutic levels in patients with high BMIs. Implementing guidelines-based monitoring resulted in more consistently and appropriately drawn trough levels.
E. F. Bello,
J. Davis, None
L. Dement, None
T. Shimasaki, None