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 45.23mL/min (interquartile range [IQR]: 32.12-58.28), and the glomerular filtration rate (GFR) predicted using the Hoek equation with CysC was 45.23mL/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.