The binding of gitoxin to human plasma proteins.

The binding of gitoxin, digitoxin and digoxin to human plasma proteins was measured by ultracentrifugation and equilibrium dialysis. At concentrations in the range of therapeutic plasma levels, protein binding amounted, respectively, to 85, 92 and 20%, the last two values being consistent with data reported in the literature. The affinity of purified human albumin was not significantly different for the three cardiac glycosides tested. No other protein than albumin was found to bind gitoxin in human plasma.