Digoxin Intoxication and Hyperkalemia-Reply

Abstract

In Reply.— We do not agree with Dr Josephson that potassium infusion is accepted in digoxin overdose, even though poisoned membrane transport is associated with reduced intracellular potassium levels. Potassium therapy in the presence of borderline or frank hyperkalemia is a two-edged sword whose possibly favorable therapeutic effects (raised threshold of myocardial excitation) 1 are balanced by (1) accentuation of underlying conduction defects, 2 (2) failure to repair the faulty ATPase-dependent membrane transport system, and (3) risk of complete loss of cardiac electrical activity, such that pacemaker therapy is ineffective in initiating a contractile response. 3 Potassium infusion in massive digoxin overdose is contraindicated as a blind maneuver and potentially hazardous in the face of high-normal to elevated serum potassium levels. This treatment would be indicated in the presence of hypokalemia or low-normal potassium levels, though only with continuous ECG monitoring. Our patient was treated with hemodialysis to reduce