Digitalis: an overview.

The use of digitalis preparations dates to the 1500s. However, it was not until the late 1700s that Withering recognized that such compounds elicited an effect on the heart. By 1790, the cardiac effects of digitalis were labeled as their primary mode of action.' Digitalis compounds continue to be popularly employed for therapeutic control of various cardiac ailments. The term digitalis is used in this article to refer to any steroid that exerts positive electrophysiological effects on the heart. 2 The most common sources of digitalis and related compounds are the leaves of the Digitalis purpurea, or royal purple foxglove, from which are derived digitoxin, digitalis leaf, and gitalin, and the leaves of the Digitalis lanata, from which are derived digoxin, lanatoside C, and deslanoside. Ouabain is derived from another source, the seeds of the Strophantus gratus.