Serum cystatin C levels to predict serum concentration of digoxin in Japanese patients.
Cystatin C (Cys-C) has been recently paid great attention as a better endogenous marker of the glomerular filtration rate than creatinine (Cr). In this study, the usefulness of Cys-C was compared with Cr in terms of the estimation of the steady-state serum trough concentrations of digoxin in Japanese patients. Forty patients treated with digoxin and 56 healthy elderly subjects were participated in this study. The serum levels of Cys-C and Cr in the patients were higher than those in the healthy elderly subjects, but the increase of Cys-C was more predominant in the patients. Their levels were well-correlated for both of the healthy elderly subjects (r=0.691) and patients (r=0.774), but the serum concentrations of digoxin were better correlated with those of the reciprocal values of Cr (r=0.667) than those of Cys-C (r=0.383), presumably due to the fact that digoxin and Cr were excreted via both glomerular filtration and tubular secretion. Cys-C is useful for the substratification of the patients diagnosed to have normal renal function with Cr of < 1.3 mg/dL into those with normal and pseudo-normal renal function, resulting in the corresponding serum concentrations of digoxin.
Nakamura
Tsutomu
T
Department of Hospital Pharmacy, School of Medicine, Kobe University, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
Ioroi
Takeshi
T
Sakaeda
Toshiyuki
T
Horinouchi
Masanori
M
Hayashi
Nobuhide
N
Saito
Kensuke
K
Kosaka
Mitsuro
M
Okamura
Noboru
N
Kadoyama
Keiichi
K
Kumagai
Shunichi
S
Okumura
Katsuhiko
K