Digoxin Toxicity

Digoxin has a narrow margin between benefit and harm. A patient can become toxic after a modest dose when renal function falls, a diuretic causes potassium loss, or a new medication raises the digoxin concentration. The serum result helps, but the patient’s rhythm, perfusion, symptoms, electrolytes, and timing of the sample determine urgency. The bedside pattern to remember is more impulse formation plus less reliable conduction. That combination explains why digoxin toxicity can produce an unusual mixture of tachyarrhythmias, bradycardia, AV block, and ventricular ectopy in the same patient.