PDR for Herbal Medicines

HERBAL MONOGRAPHS DIGITALIS/249

isolating the cardiac glycosides. Today, Digitalis lantana is

used.

Flower and Fruit: The flowers are carmine red with white-
edged spots on the inside. The flowers appear in long

hanging racemes. They have 5 free, short-tipped sepals. The
corolla is about 4 cm long, campanulate, bilabiate with an
obtuse upper lip and an ovate tip on the lower lip. The flower
is glabrous on the outside and has a white awn on the inside.
There are 2 long and 2 short stamens, and 1 superior ovary.
The fruit is a 2-valved, ovate, glandular, villous capsule.

Leaves, Stem and Root: The plant is a biennial with a

branched tap root. In the first year it develops a leaf rosette.

In the second it produces a 2 m high, erect, unbranched,

gray, tomentose stem. The leaves are alternate, ovate,

tapering upward and petiolate. Almost all leaves are crenate;

only the highest ones are entire-margined.

Characteristics: The plant is very poisonous; it tastes hot-

bitter with a slightly unpleasant odor.

Habitat: Digitalis is indigenous to Europe. It was introduced

to the east and the American continent.

Production: Digitalis leaves are the leaves of Digitalis

purpurea or of Digitalis lanata. Digitalis lanata corresponds

to Digitalis purpurea but has a milder effect. The rose leaves

are harvested during the first period of vegetation in early

autumn. The drying period is decisive for the content of

cardenolide glycosides. The temperature for drying is 30° C

to 50° C.

Not to be Confused With: Confusion seldom occurs due to

cultivation under controlled conditions.

Other Names: Foxglove, Dead Men's Bells, Dog's Finger,

Fairy Fingers, Fairy Gloves, Finger Rower, Folks' Glove,

Lion's Mouth, Ladies' Glove, Witches' Gloves, Gloves of

Our Lady, Fairy Caps, Fairy Thimbles, Virgin's Glove

ACTIONS AND PHARMACOLOGY

COMPOUNDS

Cardioactive steroid glycosides (cardenolides 0.5 to 1.5%):

including ones of the -

• A-sequence (aglycone digitoxigenin): purpurea glyco-
  side A (primary glycoside), digitoxin (secondary glycoside)


• B-sequence (aglycone gitoxigenin): purpurea glycoside
  B (primary glycoside), gitoxin (secondary glycoside), Digita-
  linum verum


• E-sequence (aglycone gitaloxigenin): glucoverodoxin,
  glucogitaloxin, gitaloxin

Pregnane glycosides: including digipurpurin, diginin,

digitalonin

Steroid saponin: including desgalactotigonin. digitonine,

purpureagitoside

Anthracene derivatives: anthraquinones

EFFECTS

The drug contains cardioactive cardenolide glycosides that

are positively inotropic, negatively chronotropic and improve

the contraction power of cardiac muscle.

INDICATIONS AND USAGE

Unproven Uses: In folk medicine, the drug's use originated

in Ireland, then came to Scotland and England and finally to

central Europe. It was used to treat ulcers in the lower

abdomen, boils, headaches, abscesses and paralysis. Exter-

nally, the drug was used for the granulation of poorly healing

wounds and to cure ulcers. Furthermore, the drug was used

for cardiac insufficiency, especially high blood pressure.

Use of the raw product has become obsolete because the

effect is not reproducible. The use of pure glycosides is

recommended instead. Digitoxin is available in mono

preparations (extract) and is used as an isolated pure

substance.

Homeopathic Uses: Digitalis purpurea is used for cardiac

insufficiency and migraine.

PRECAUTIONS AND ADVERSE REACTIONS

General: Because of the narrow therapeutic range of digitalis

glycosides, a certain percentage of patients may experience

side effects immediately upon administration of therapeutic

dosages: hypertonia in gastrointestinal area, loss of appetite,

vomiting, diarrhea and headache.

Drug Interactions: The simultaneous administration of

arrhythmogenic substances (sympathomimetics, methylxan-

thines, phosphodiesterase inhibitors, quinidine) increases the

risks of cardiac arrhythmias.

OVERDOSAGE

With overdosage, in addition to the already-mentioned

symptoms, the following can also occur:

Heart: cardiac rhythm disorders, all the way up to life-

threatening ventricular tachycardia, atrial tachycardia with

atrioventricular block

Central nervous system: stupor, visual disorders, depression,

confused states, hallucinations, psychoses

Lethal dosages lead to heart failure or asphyxiation. Admin-

istration over extended periods leads in rare cases to

gynecomastia. Because of the difficulties in standardizing

the drug, the administration of pure glycosides is to be

preferred (digitoxin).

The first measures to be taken in case of poisoning are

gastric lavage and activated charcoal instillation. All other