Joseph Hong1, Lynne C Krop1, Tracy Johns2,3, Manjunath P Pai4. 1. Morton Plant Hospital, BayCare Health System, Clearwater, Florida. 2. University of South Florida Family Medicine Residency, Clearwater, Florida. 3. Dr. Joseph A. Eaddy Family Medicine Research Center, Clearwater, Florida. 4. Albany College of Pharmacy and Health Sciences, Albany, New York.
Abstract
STUDY OBJECTIVE: To compare the likelihood of vancomycin target trough concentration attainment based on infectious diagnosis and/or minimum inhibitory concentration for the organism by using a two-sample approach versus the prior institutional standard of a trough-only approach in obese patients receiving vancomycin. DESIGN: Preintervention and postintervention study. SETTING: Community acute care hospital. PATIENTS: One hundred fifty hospitalized adults with a body mass index (BMI) of 30 kg/m(2) or greater and treated with vancomycin for at least 48 hours between July 2013 and March 2014 were evaluated to compare the frequency of steady-state therapeutic trough concentration attainment between two approaches: a trough-only dosing method (preintervention group [75 patients]) and a dosing strategy measuring two vancomycin serum concentrations during the elimination phase (peak and trough) to calculate pharmacokinetic parameters and individualize the maintenance regimen (postintervention group [75 patients]). Data for the preintervention group were retrospectively retrieved from a 4-month period for patients admitted between July and October 2013, prior to implementation of the two-point vancomycin dosing protocol. Initial vancomycin empiric dose selection for both groups utilized the same population-based pharmacokinetic equations. MEASUREMENTS AND MAIN RESULTS: Median (5th-95th percentile) age, weight, and BMI were 59 (34-80) years, 105 (79.8-164) kg, and 34.5 (30.0-55.1) kg/m(2) , respectively, for all patients. The percentages of initial therapeutic trough concentrations achieved in the preintervention and postintervention groups were 32.0% and 42.7%, respectively (p=0.117). For patients with a second trough measurement, 31.0% in the preintervention group and 65.2% in the postintervention group were within the therapeutic range (p=0.024). CONCLUSION: Measurement of two serum vancomycin concentrations significantly improves subsequent target trough concentration attainment in the obese population.
STUDY OBJECTIVE: To compare the likelihood of vancomycin target trough concentration attainment based on infectious diagnosis and/or minimum inhibitory concentration for the organism by using a two-sample approach versus the prior institutional standard of a trough-only approach in obesepatients receiving vancomycin. DESIGN: Preintervention and postintervention study. SETTING: Community acute care hospital. PATIENTS: One hundred fifty hospitalized adults with a body mass index (BMI) of 30 kg/m(2) or greater and treated with vancomycin for at least 48 hours between July 2013 and March 2014 were evaluated to compare the frequency of steady-state therapeutic trough concentration attainment between two approaches: a trough-only dosing method (preintervention group [75 patients]) and a dosing strategy measuring two vancomycin serum concentrations during the elimination phase (peak and trough) to calculate pharmacokinetic parameters and individualize the maintenance regimen (postintervention group [75 patients]). Data for the preintervention group were retrospectively retrieved from a 4-month period for patients admitted between July and October 2013, prior to implementation of the two-point vancomycin dosing protocol. Initial vancomycin empiric dose selection for both groups utilized the same population-based pharmacokinetic equations. MEASUREMENTS AND MAIN RESULTS: Median (5th-95th percentile) age, weight, and BMI were 59 (34-80) years, 105 (79.8-164) kg, and 34.5 (30.0-55.1) kg/m(2) , respectively, for all patients. The percentages of initial therapeutic trough concentrations achieved in the preintervention and postintervention groups were 32.0% and 42.7%, respectively (p=0.117). For patients with a second trough measurement, 31.0% in the preintervention group and 65.2% in the postintervention group were within the therapeutic range (p=0.024). CONCLUSION: Measurement of two serum vancomycin concentrations significantly improves subsequent target trough concentration attainment in the obese population.