Digoxin

Digoxin is a cardiac glycoside that strengthens contraction and slows heart rate in heart failure and atrial fibrillation. Take the apical pulse for a full minute and hold the dose, notifying the provider, if it is below 60; the therapeutic level is a narrow 0.5–2 ng/mL. Watch for toxicity — nausea, visual changes such as yellow or green halos, and arrhythmias — which is worsened by low potassium, so monitor potassium closely.