The appropriateness of initial vancomycin dosing

Abstract

Background: Vancomycin use has markedly increased over the past several years because of an increased incidence of resistant organisms, particularly methicillin-resistant Staphylococcus aureus. Despite the availability of dosing nomograms and the use of peak and trough levels, vancomycin dosing has remained problematic.

Methods: All intravenous vancomycin orders over a 3-month period in a community and teaching hospital were screened for appropriateness of initial dosing based on available dosing nomograms.

Results: Of the 48 patients who received intravenous vancomycin, only 19 (39.6%) were given initial doses that achieved the desired serum concentration. There were no significant differences in the appropriateness of initial dosing between family medicine residents, attending physicians, and private staff physicians. Older patients in our study were at higher risk for overdosing, whereas younger patients were more likely to be underdosed. In this study, nomogram use could have yielded correct initial dosages in 40 of the 48 patients (83.3%).

Conclusions: Our study indicates a high percentage of inappropriate initial vancomycin dosing in a community and teaching hospital. The investigators believe inappropriate initial vancomycin dosing is common and may result in unnecessary expense, increased risk of therapeutic failures, and greater potential for adverse drug reactions. Increased use of vancomycin dosing nomograms could improve the rate of correct initial dosages.