Abstract
1 Measurements of the binding of 12-alpha-[3H]-digoxin to the membranes of intact erythrocytes, erythrocyte 86rubidium uptake and intraerythrocytic sodium concentrations have been made in the red cells of various groups of patients-those who have not received digoxin, those during the early phases of treatment, those during chronic (greater than 2 months) treatment, and those toxic. 2 The values of those measurements in the patients in the early phases of therapy and in the toxic patients differed significantly from those of the untreated patients. 3 However, the values in the chronically treated patients were not different from those of the untreated patients. 4 The results suggest that the biochemical pharmacological effects of digoxin which occur during the early phases of therapy do not persist in the long-term. 5 The possible clinical significance of these observations is discussed.