Relationship between Initial Vancomycin Concentration‐Time Profile and Nephrotoxicity among Hospitalized Patients

Abstract

Background. Data suggest that higher doses of vancomycin can increase the risk of nephrotoxicity. No study has been undertaken to determine the pharmacodynamic index (ie, the area under the curve [AUC] or the trough value) that best describes the relationship between vancomycin exposure and onset of nephrotoxicity. Methods. A retrospective study was conducted among patients who received vancomycin for a suspected or proven gram-positive infection during the period from 1 January 2005 through 31 December 2006 at Albany Medical Center Hospital. Patients were included in our study if they (1) were ⩾18 years old, (2) had an absolute neutrophil count of ⩾1000 cells/mm³, (3) received vancomycin for >48 h, (4) had ⩾1 vancomycin trough level collected within 96 h of vancomycin therapy, and (5) had a baseline serum creatinine level of Results. During the study period, 166 patients met the inclusion criteria. Both initial vancomycin trough values and 0–24-h at steady state AUC values were associated with nephrotoxicity in the bivariate analyses. However, the vancomycin trough value, modeled as a continuous variable, was the only vancomycin exposure variable associated with nephrotoxicity in the multivariate analyses. Conclusions. The results indicate that a vancomycin exposure-toxicity response relationship exists. The vancomycin trough value is the pharmacodynamic index that best describes this association.