Limitations of Hemofiltration in Digoxin Overdose-Reply

—We agree with the comment of Doherty and Conrad that the amount of digoxin removed by hemofiltration for 21 hours was minute despite the modest fall in the serum digoxin level. The digoxin concentration during maintenance therapy is much lower in skeletal muscle than in the myocardium despite the fact that skeletal muscle forms the largest storage depot of digoxin. The ratio between the concentrations in the plasma and the heart is reportedly between 1:30 and 1:200. 1 As the cardiotoxicity is due to interaction of cardiac glycoside with the cellular receptor, the effective and progressive removal of drug from receptor sites as the drug-receptor equilibrium is displaced in the direction of dissociation is essential in reversing digoxin cardiotoxicity. 2 Immediate removal of digoxin from other body depots such as skeletal muscle is therefore of lesser importance in the acute management of these critically ill patients. The exact quantitative