Overestimation of Vancomycin Clearance by the Linear Regression Formula in Rodvold's Report: Why?

Vancomycin therapy has long been individualized through concentration monitoring. Because the therapeutic drug concentration monitoring (TDM) service is not available in all hospitals, ways to predict its area under the curve (AUC) using estimated creatinine clearance (CLcr) without drug concentration have been sought. More than 80% of vancomycin is eliminated via renal excretion and its clearance (CL) is known to be approximately 50-80% of measured glomerular filtration rate (GFR) [1]. Thus, an equation describing linear relationship between vancomycin clearance (CL) and CLcr may be used to predict vancomycin AUC without measuring its concentration.