Digitalis: new aspects of pharmacokinetics and clinical implications

Any evaluation of the efficacy of digoxin therapy must rely upon a precise index of the digitalization status. As the plasma concentrations bear a rather poor relationship with clinical effects of treatment, the occupied fraction of digoxin receptors (Na-K ATPase) on the erythrocytes membranes is proposed as a new index of digitalization status; preliminary data on the value of this approach are discussed.