The effect of colestipol on digitoxin plasma levels

The effect of colestipol (colestipol hydrochloride; U-26 597 A), a copolymer of tetraethylenepentamine and epichlorhydrine, on plasma digitoxin levels has been investigated. Recently, it has been stated that colestipol decreases the enterohepatic circulation and the plasma half-life of digitoxin. Colestipol was administered to 11 patients having a digitoxin plasma level which is generally accepted to be above the therapeutic range (greater than 40 ng/ml). The elimination rate of digitoxin measured by serial radioimmunoassay in these colestipol treated patients was compared with the elimination rate of digitoxin in 11 patients not treated with colestipol. The results of this study did not demonstrate a significant difference in the mean (+/- S.D.) digitoxin plasma half-life between the colestipol treated (6.3 +/- 1.3 days) and the non-colestipol treated patients (6.8 +/- 1.0 days).