Comparison of predictive accuracy of teicoplanin concentration using creatinine clearance and glomerular filtration rate estimated by serum creatinine or cystatin C

Abstract We compared the predictive accuracy of TEIC concentrations (TEIC _conc ) calculated using either serum cystatin C (CysC) or serum creatinine (SCr) and the population mean method using the mean population parameter of TEIC _conc for Japan. We also compared the predicted TEIC _conc to measured TEIC _conc . Creatinine clearance (CLCr) predicted using the Cockcroft-Gault (C&G) equation with SCr was 45.23 mL/min (interquartile range [IQR]: 32.12–58.28), and the glomerular filtration rate (GFR) predicted using the Hoek equation with CysC was 45.23 mL/min (IQR: 35.40–53.79). The root mean-squared prediction error (IQR) based on CLCr predicted using the C&G equation with SCr was 6.88 (3.80–9.96) μg/mL, and that based on GFR predicted using the Hoek equation with CysC was 6.72 (3.77–9.68) μg/mL. Predicted TEIC _conc did not differ significantly between the two methods. The predictive accuracy of the TEIC _conc using the Hoek equation with CysC was similar to that of CLCr using the C&G equation with SCr. These findings suggest that the predictive accuracy of the TEIC _conc using CLCr based on the G&G equation and SCr might be sufficient for the initial dose adjustment of TEIC. Given that we were unable to confirm that CysC is the optimal method for predicting TEIC _conc , the expensive measurement of CysC might not be necessary.