Hoek's formula, a cystatin C-based prediction formula for determining the glomerular filtration rate, is the most effective method for original adjusting the dosage of vancomycin.

OBJECTIVE

Some formulas using the serum cystatin C level to estimate the GFR have recently been reported. However, there has been no report of a serum cystatin C-based formula for adjusting the dosage of the drugs cleared by the kidney. In this study, we compared the predictive performance of the serum vancomycin trough concentration predicted using serum cystatin C-based formulas.

METHOD

The data were collected from 158 hospitalized patients. Five formulas have been published to predict the GFR using serum cystatin C. The cystatin C-based formulas were divided into two groups, formulas with or without anthropometric data. We predicted the serum vancomycin trough concentrations using VCM-TDM S_edition ver. 1.00 software.

RESULTS

In formulas with anthropometric data, the mean absolute error (MAE) using Hoek's formula was 2.38, the MAE using Grubb's 1 formula was 4.13, the MAE using Sjöström's formula was 2.90, and the MAE using Cockcroft and Gault formula based on creatinine was 4.42. On the other hand, in formulas without an anthropometric data group, the MAE using Larsson's formula was 3.07, and the MAE using Grubb's 2 formula was 3.63.

CONCLUSION

These results suggested that Hoek's formula is the most useful formula for determining the initial dosage settings for vancomycin.