... digoxin. Key words: Cystatin C, Creatinine, Digoxin, Serum concentration, Heart failure, Renal clearance 1. Introduction Cystatin C (Cys -C) is a non-glycosylated cationic protein of 13.3 kDa, ... Gorman RT, Scott MG. Reference intervals for plasma cystatin C in healthy volunteers and renal patients, as measured by the Dade Behring BN II System, and correlation with creatinine. Clin Chem. ... 19(3):7–17. 21. Nakamura T, Kakumoto M, Yamashita K, Takara K, Tanigawara Y, Sakaeda T, Okumura K. Factors influencing the prediction of steady state concentrations of digoxin. Biol Pharm Bull. 2001;...