thimble

Of the thimble is a poisonous plant that is under nature protection. As early as the 18th century, it was used medicinally against heart failure. In conventional medicine, the ingredients of the thimble are still a proven remedy for heart diseases.

Occurrence & cultivation of the foxglove

The foxglove grows as a biennial, herbaceous plant and is up to two meters high. It blooms from June to August. Of the thimble, Latin digitalis, is a genus of plants from the plantain family (Plantaginaceae). The Latin name digitalis is derived from the word digitus for finger and refers to the flowers, which are similar in shape to a thimble. The red thimble is most common in Central Europe (Digitalis purpurea) in front.

In Europe there are also other types of foxgloves, including the large-flowered foxglove, the yellow foxglove and the woolly foxglove. All parts of the plant are very poisonous, although all types of foxgloves are similar in terms of effect and toxicity. The foxglove grows as a biennial, herbaceous plant and is up to two meters high. It blooms from June to August.

The flowers of the terminal, racemose inflorescence have a purple or rarely white color in the red foxglove. The flower colors of the other foxgloves are yellow to gray-yellow. The plant is found mainly in clearings, on the edges of forests and on clear cuts. As an ornamental plant, foxgloves have been planted in parks and gardens since the 16th century.

Effect & application

The English physician William Withering discovered the effects of thimble on patients with dropsy in the 18th century. He is considered a pioneer in the medicinal use of thimble. The external use of thimble leaves was first mentioned in the 12th century for the treatment of ulcers. Later, thimble was also used as an emetic, the effect of which was probably based on symptoms of poisoning and was often fatal.

As a result, the plant fell into disrepute and only regained importance in therapy through withing. By investigating different dosages of thimble, he distinguished for the first time between therapeutic and toxic effects. The effect of thimble is based on various cardiac glycosides such as the so-called digitoxin, which are contained in the plant. These cardiac glycosides bind to a specific enzyme, sodium-potassium-ATPase, in the cells of the heart muscle. This inhibits the activity of this enzyme.

There is an accumulation of calcium in the cells of the heart muscle. This prevents the heart muscle from relaxing and stimulates the weakened heart muscle to contract more. The performance of the heart is strengthened, thereby the heart rate slows down. In addition, the conduction of excitation to the heart is delayed. The cardiac glycosides are usually obtained from the red or woolly thimble.

For cardiac insufficiency, palpitations and cardiac arrhythmias, preparations with cardiac glycosides from the thimble are used as well as for [[Angina pectoris]] or edema caused by heart failure. Digitalis preparations have a very long half-life. Digitoxin has a half-life of one week, which means that after this time half of the active ingredient is broken down.

Standardized digitalis preparations for which the exact concentration of the active ingredient is known must be used for therapy with thimble. The use of teas or tinctures made from thimble is not recommended, as the cardiac glycoside content can vary greatly. Standardized digitalis preparations are available for internal use as tablets, drops and ampoules. Contact with the leaves of the foxglove plant can lead to allergy-like rashes.

Importance for health, treatment & prevention

Lowering the heart rate, such as in certain forms of cardiac arrhythmia, is the top priority in therapeutic use. Digitalis preparations are the means of choice for this. It is used for heart failure when other drugs such as ACE inhibitors or beta blockers are no longer effective enough on their own. The positive effects of digitalis preparations only show themselves in the case of illness or weakness of the heart.

In a healthy heart, the cardiac glycosides have no effect other than undesirable side effects. As the consumption of just two leaves of the thimble can lead to fatal poisoning, self-medication is strongly discouraged. Since the plant has a very bitter taste, poisoning from consumption is rare. Because of its high toxicity, thimble is rarely used in naturopathy.Only in homeopathy is foxglove administered under the name Digitalis in potencies D6 to D12.

The dilution steps mean that there is no longer any toxic effect. In conventional medical therapy with digitalis preparations, the dose must be set carefully, as the active ingredients accumulate in the body. In addition, the dosage in which the agents develop their effect is close to an already toxic dose. The first signs of poisoning with nausea, vomiting, dizziness and a low heart rate may therefore appear more frequently.

Severe intoxication with digitalis can lead to impaired vision, impaired consciousness, disorientation and a drop in blood pressure up to cardiac arrest and death. Possible side effects of digitalis therapy are also cardiac arrhythmias, digestive problems and nerve disorders. Due to the side effects and the risks of poisoning, preparations containing digitalis require a prescription and the therapy must be supervised by experienced doctors.

In the event of side effects, patients should never adjust the dosage on their own, but should contact their doctor immediately. However, since digitalis preparations are proven, effective and inexpensive heart medication, treatment by an experienced doctor can be beneficial and safe for the patient.