Possible Interaction: Cardiac Glycosides and Potassium

“This postulation that the inotropic and certain toxic actions of digitalis are mediated by different mechanisms is important clinically, since the two properties of the glycoside can be dissociated by the administration of potassium.”

“Evidence … the cardiac glycosides may initiate important … the concentration of potassium (K) in both cellular and extracellular fluid.l-4 Their administration to normal dogs usually produces slight increases in … K.1 Two clinical observations have also suggested a peculiarity of action of this drug in the uremic state.”

“Low magnesium and potassium concentrations increase cardiac glycoside toxicity.”

“In the presence of the glycoside , the responses to noradrenaline and potassium are potentiated.”

“Since the fluxes of sodium and potassium in red cells … quite small, the net changes in cellular sodium and potassium concentrations as conditioned, for example, by an … of active cation transport by adding a cardiac glycoside , can hardly be run t o a … state in v i t ro .”

“IT is generally believed from Schatzmann's1 work that lactate production in human erythrocytes is unaffected by ouabain and other cardiac glycosides which inhibit the active transport of sodium and potassium.”

“The part activated by sodium and potassium amounts to 30–50 per cent of the total, and is further characterized by being inhibited by cardiac glycosides.”

“Approximately 80 per cent of the potassium influx can be inhibited by the glycoside by an action that appears to involve competition by drug and potassium ions for the active transport site.”

“The inhibition was similar to that produced by cardiac glycosides since it was dose-dependent, antagonised by potassium and the Na,K-ATPase prepared from brain was more sensitive than the one from heart.”

“On the other hand toxic concentrations of cardiac glycosides significantly produce a loss of cellular potassium and a rise of cellular sodium and calcium content, especially if arrhythmias are present.”