Digitalis

Digitalis is a cardiac glycoside commonly prescribed to patients with heart failure or atrial fibrillation. It is extracted from the leaves of a flowering plant, Digitalis purpurea, commonly called foxglove. It is available in the United States as digoxin (trade name Lanoxin) and is the oldest cardiac medication as well as the only approved cardiac glycoside. The medicinal use of this plant was first discovered by Sir William Withering in 1785, and since then this drug has been used in the management of heart failure and atrial fibrillation, though its clinical utility has declined over the years due to the increased risk of digoxin toxicity attributed to the narrow therapeutic index of the drug.

Several mechanisms of action have been proposed for digoxin, and the approved ...