Evaluation of the Safety of a Vancomycin Nomogram Used to Achieve Target Trough Concentrations

Abstract

Background

Dosing vancomycin to achieve target concentrations of 15 to 20 mg/L has been recommended for select infections. To date, few vancomycin nomograms designed to target these higher concentrations have been published, and only one has been published in North America. Based on the success of this nomogram in developing empiric vancomycin regimens that achieve higher target trough concentrations with low rates of nephrotoxicity, a vancomycin nomogram targeting concentrations of 15 to 20 mg/L was developed and implemented at Emory University Hospital and Emory University Hospital Midtown.

Objective

To evaluate the impact of a vancomycin-dosing nomogram on the incidence of vancomycin- associated nephrotoxicity and the time to achieve targeted trough concentrations.

Methods

A retrospective chart review of 200 patients who received vancomycin dosed to achieve target trough serum concentrations of 15 to 20 mg/L was performed.

Results

After implementation of the vancomycin nomogram, no statistically significant difference in incidence of vancomycin-associated nephrotoxicity was found (14% vs 16%; P = .197). Fewer patients had an initial vancomycin trough concentration within target range (29.1% vs 21.7%; P < .001). Adherence to the nomogram was poor, with only 41% of patients being dosed per the nomogram's recommendations.

Conclusion

Based on our results, implementation of a vancomycin dosing nomogram had no impact on the incidence of nephrotoxicity, and significantly fewer patients had an initial vancomycin trough within the target range of 15 to 20 mg/L. The clinical utility of a vancomycin dosing nomogram is still to be determined.