Effect of digoxin on human red blood cell electrolytes.

Red blood cell electrolytes were measured during 48 h after administration of digoxin to twelve patients. The concentrations of some red cell electrolytes changed: sodium increased while potassium decreased significantly. These findings agree with in vitro experiments on red cells and other tissues including myocardium. Change in membrane ATPase activity is probably responsible for the electrolyte changes both in vitro and in vivo.