Iranian Red Crescent Medical Journal Iran Red Crescent Med J 2011; 13(9):680-681 ©Iranian Red Crescent Medical Journal LETTER TO THE EDITOR Good Outcome after Digoxin Toxicity Despite Very High Serum Potassium Level

Digoxin, as a cardiac glycoside extracted from the Digitalis lanata1 is widely used in the treatment of different heart diseases, such as atrial fibrillation, atrial flutter and heart failure.2 Its effect is to increase myocardial contractility while mildly prolonging the duration of contraction. The result is decreased heart rate, increased blood pressure and stroke volume, leading to increased tissue perfusion, improved myo-cardial function and hemodynamics.2 Digoxin inter-acts with verapamil, amiodarone, and erythromycin, leading to increase in its plasma level.3 Arrhythmo-genesis and atrio-ventricular conduction arrhythmias such as paroxysmal atrial tachycardia with A-V block are diagnostic for digoxin toxicity.4 Without the use of digoxin-specific Fab fragments, in a recent review