Serum cystatin C as a better marker of vancomycin clearance than serum creatinine in elderly patients.
OBJECTIVE
The purpose of this study is to assess the usefulness of the concentration of cystatin C (Cys-C) in serum for predicting the clearance of vancomycin (CLvcm) compared with the serum concentration of creatinine (SCr) in the elderly.


METHODS
Thirty-nine serum samples were obtained from 24 elderly patients (65 years and older). Creatinine clearance (CLcr) and the glomerular filtration rate calculated from the concentration of Cys-C (GFRcys-c) were estimated using Cockcroft & Gault's formula and Larsson's formula, respectively.


RESULTS
The correlation constant for CLvcm and the reciprocal of Cys-C (p=0.883) was significantly higher than that for CLvcm and the reciprocal of SCr (p=0.575, p<0.005). GFRcys-c was strongly correlated with CLvcm (p=0.883) and the constant was significantly higher than that for the correlation between CLvcm and CLcr (p=0.684, p<0.05). These results suggest that the serum concentration of Cys-C is a more reliable marker for predicting CLvcm than is SCr in elderly patients.
Okamoto
Go
G
Department of Clinical Pharmaceutics and Pharmacy Practice, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan.
Sakamoto
Tatsuichiro
T
Kimura
Midori
M
Ukishima
Yoshiyuki
Y
Sonoda
Akihiro
A
Mori
Noriko
N
Kato
Yasuhiro
Y
Maeda
Toshio
T
Kagawa
Yoshiyuki
Y
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000493:pharmacokinetics; D015415:Biomarkers / Q000097:blood*; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D005260:Female; D016231:Fluorescence Polarization Immunoassay; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D008657:Metabolic Clearance Rate; D014640:Vancomycin / Q000008:administration & dosage / Q000493:pharmacokinetics*
D000900:Anti-Bacterial Agents; D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D014640:Vancomycin; D003404:Creatinine