Digitalis

Digitalis is a genus of about 20 species of herbaceous perennials, shrubs, and biennials commonly called foxgloves. This genus was traditionally placed in the figwort family Scrophulariaceae, but recent phylogenetic research has placed it in the much enlarged family Plantaginaceae. This genus is native to western and southwestern Europe, western and central Asia and northwestern Africa. The scientific name means "finger-like" and refers to the ease with which a flower of Digitalis purpurea can be fitted over a human fingertip. The flowers are produced on a tall spike, are tubular, and vary in colour with species, from purple to pink, white, and yellow. The best-known species is the common foxglove, Digitalis purpurea. This biennial plant is often grown as an ornamental plant due to its vivid flowers which range in colour from various purple tints through various shades of light gray, and to purely white. The flowers can also possess various marks and spottings.

Medical uses

The first recorded use of foxglove dates back to 1775. The plant is a source of a drug that is used to treat heart conditions. In the original description of digitoxin, Sir William Withy FRS noted that the plant was known by herbalists for causing vomiting and diarrhea, and sometimes hallucinations. Digitalis is used to treat congestive heart failure (CHF) and heart rhythm problems (atrial arrhythmias). It was the original source of the drug called digitalis and the family of drugs derived from it.

Toxicity

All parts of the plant are toxic, and eating it, especially the leaves, can cause severe poisoning. A group of medicines extracted from foxglove plants are called digitalin. The use of D. purpurea extract containing cardiac glycosides for the treatment of heart conditions was first described in the English-speaking medical literature by William Withering, in 1785, which is considered the beginning of modern therapeutics. It is used to increase cardiac contractility (it is a positive inotrope) and as an antiarrhythmic agent to control the heart rate, particularly in the irregular (and often fast) atrial fibrillation. Digitalis is hence often prescribed for patients in atrial fibrillation, especially if they have been diagnosed with congestive heart failure. "Digitalis" drugs are used less frequently because of the advent of "beta-blocker" drugs.

See also

• Cardiac glycoside
• William Withering

External links

• Botanical.com – A Modern Herbal | Foxglove

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  Digitalis purpurea
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  Digitalis lutea
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  Common foxglove
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  A Foxglove in Bloom, 1592 by Hendrik Goltzius
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  Digitalis purpurea patch in Seattle
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  Foxglove - Digitalis purpurea
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  Digitalis purpurea Koehler drawing