CLINICAL APPLICATION AND EVALUATION OF VANCOMYCIN DOSING IN ADULTS
Todd A Rushing and Peter J Ambrose

OBJECTIVE: To evaluate the accuracy of a vancomycin dosing method (study method) in estimating volume of distribution (V_d) and clearance of vancomycin (Cl_vanco) and the frequency with which it would provide serum vancomycin concentrations (SVCs) within a specified range compared with other published methods.

METHODS: One hundred and seven patients with 108 pairs of SVCs were used to calculate patient-specific V_d and Cl_vanco. Based on these patient-specific Vd and Cl_vanco values, the predictive ability of the estimated parameters from the study dosing method (V_d [L] = 0.17 [age] + 0.22 [actual body weight] + 15; Cl_vanco = creatinine clearance) was evaluated against three previously published pharmacokinetic dosing methods, using predictive performance analysis (precision and bias). Furthermore, the patient-specific pharmacokinetic parameters were used to simulate steady-state peak and trough SVCs, using first-order pharmacokinetic equations from doses derived from the study method, the three different pharmacokinetic methods, and two other published dosing schemes. The frequency with which each method would have achieved target peak and trough SVCs was determined.

RESULTS: The study method was found to be more precise and less biased (p < 0.05) than comparative methods in predicting vancomycin V_d and Cl_vanco. The study method also resulted in a higher frequency of steady-state peak and trough SVCs within the target range specified.

CONCLUSIONS: The study method presented here provided a reliable estimation of vancomycin pharmacokinetic parameters that was easily applied to various patient populations to individualize vancomycin dosing, and frequently yielded SVCs within a predictable and desired range.

J Pharm Technol 2001;17:33-8.