Digitalis, << `dihj` uh TAL ihs, >> is the dried leaves of the purple foxglove, a garden flower. The word digitalis comes from Digitalis purpurea, the scientific name for this flower. In the past, doctors used digitalis to treat patients with heart failure or irregularly beating hearts.
The British physician William Withering is credited with first documenting the medicinal value of the purple foxglove in 1785. Scientists later determined that the leaves of the purple foxglove contain chemical compounds called glycosides. One of these glycosides, called digitoxin, was found to be particularly powerful in treating certain heart problems. Researchers also discovered that the leaves of the yellow foxglove (Digitalis lanata) contain digoxin, a glycoside even more useful in the treatment of such heart problems.
Today, chemists make pure preparations of either digoxin or digitoxin. Doctors use these drugs in treating congestive heart failure to strengthen contractions of the weakened heart. These drugs also slow the heartbeat, making them useful in treating atrial fibrillation (a type of irregular, abnormally rapid heartbeat). Both drugs can be taken in tablet form. Digoxin can also be put in a liquid solution, which is injected into a vein or taken orally. Digitalis drugs can be toxic and should be taken only as directed by a doctor.
