Clinical Application and Evaluation of Vancomycin Dosing in Adults

Abstract

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 V d 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.

Population Pharmacokinetic Analysis of Vancomycin in Patients with Hematological Malignancies

“…The mean values (expressed in a homogeneous system of units to allow comparisons) obtained for VAN clearance and V in this study using NONMEM (1.19 ml/min/kg of body weight and 1.05 liters/kg) are slightly higher than the values reported in other studies using standard approaches (two-stage methods with a one-compartment model) in other adult populations (6,7,14,25,28,29,38,39). Also, the mean values accounting for the effect of renal function and TBW on VAN clearance and V, respectively, were higher than the ranges quoted for this antibiotic in other adult populations (26,30,50).…”

Comparing two predictive methods for determining serum vancomycin concentrations at a Veterans Affairs medical center

“…Several similarities and differences exist among the previous studies by Rushing and Ambrose 3 and Leonard and Boro 2 and the current study. The current study population resembled that of Leonard and Boro 2 in that both were conducted in a veterans population, with nearly all male patients (97.5% and 100%, respectively) of moderately advanced age male (97.5%) and of moderately advanced age (mean ± S.D.…”

“…Zero is not included in the 95% CI of either group, indicating a signifi cant diff erence in bias between methods for both groups. 3 (107 patients with 216 SVCs). The categories of SVCs in the three studies varied greatly.…”

“…Various vancomycin dosing methods have been described and are based on patient-specifi c factors such as weight, creatinine clearance (CL cr ), and age. [2][3][4][5][6][7] In a study of veterans, Leonard and Boro 2 found that the equations CL = 0.9 × CL cr (mL/min/kg) × ABW and V = 0.7 L/kg × ABW better predicted SVCs than the conventional method (CL = 0.65 × CL cr [mL/min/kg] × ABW and V = 0.7 L/kg × ABW), where V = volume of distribution, ABW = actual body weight in kilograms, CL = vancomycin clearance in milliliters per minute, and CL cr is based on a derivation of the Cockcroft and Gault equation, 8 where no weight is entered to generate a CL cr in milliliters per minute per kilogram. The 0.9 × CL cr factor was derived retrospectively from regression analysis.…”

Evaluation of methods to estimate glomerular filtration rate versus actual drug clearance in patients with chronic spinal cord injury

“…16 Patient-specific vancomycin volume of distribution (Vd) was calculated using the Rushing and Ambrose method. 17 Empiric vancomycin clearance and AG clearance are equal to the estimated creatinine clearance (CL CR ), according to the method described by CG. 1 Estimation of pharmacokinetic parameters of vancomycin and AG was made using a one-compartment open model.…”