Evaluation of a New Vancomycin Dosing Protocol in Morbidly Obese Patients
Background Optimal dosing of vancomycin in morbidly obese patients (>100 kg and at least 140% of their ideal body weight) has not been determined. Conventional dosing strategies have led to the observation of supratherapeutic trough concentrations (>20 mcg/mL). Objective To evaluate the effect...
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Published in | Hospital pharmacy (Philadelphia) Vol. 50; no. 9; pp. 789 - 797 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Los Angeles, CA
SAGE Publications
01.10.2015
Thomas Land Publishers, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | Background
Optimal dosing of vancomycin in morbidly obese patients (>100 kg and at least 140% of their ideal body weight) has not been determined. Conventional dosing strategies have led to the observation of supratherapeutic trough concentrations (>20 mcg/mL).
Objective
To evaluate the effectiveness of a new vancomycin dosing protocol in morbidly obese patients in achieving therapeutic trough concentrations between 10 and 20 mcg/mL and to determine patient-specific factors influencing the trough concentration attained.
Methodology
A single-center, retrospective chart review included morbidly obese adult patients with a pharmacy-to-dose vancomycin consult and at least 1 trough concentration obtained at steady state. Patients were excluded if they had a creatinine clearance (CrCl) less than 35 mL/min or unstable renal function, were not dosed according to the revised protocol, or received vancomycin prior to initiation of the protocol.
Results
Of the 48 patients included, 17 (35.4%) achieved a therapeutic vancomycin trough concentration. Subtherapeutic concentrations (<10 mcg/mL) were observed in 27 patients (56.3%) and supratherapeutic concentrations were observed in 4 (8.3%) patients. Age less than 45 years and CrCl greater than 100 mL/min were associated with subtherapeutic trough concentrations.
Conclusion
This study demonstrates that the revised vancomycin dosing protocol led to the attainment of therapeutic trough concentrations in 35.4% of patients. The majority had subtherapeutic concentrations, which increases the risk of treatment failures and resistance. Further study is needed to determine the optimal dosing strategy in this patient population. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0018-5787 1945-1253 |
DOI: | 10.1310/hpj5009-789 |