Digitalis - medicinal properties in traditional medicine recipes. Medicinal properties of foxglove and other advantages of the plant How to prepare medicinal raw materials from foxglove

Facilities. More than 200 years ago, it was found that they selectively affect the heart, enhancing its activity, normalizing blood circulation, which provides a decongestant effect.

Pharmacodynamic effects of cardiac glycosides are due to their effect on the cardiovascular, nervous systems, kidneys and other organs.

The mechanism of cardiotonic action is associated with the effect of cardiac glycosides on metabolic processes in the myocardium. They interact with the sulfhydryl groups of the transport Na + , K + -ATPase of the membrane of cardiomyocytes, reducing the activity of the enzyme. The ionic balance in the myocardium changes: the intracellular content of potassium ions decreases and the concentration of sodium ions in myofibrils increases. This contributes to an increase in the content of free calcium ions in the myocardium due to their release from the sarcoplasmic reticulum and an increase in the exchange of sodium ions with extracellular calcium ions. An increase in the content of free calcium ions in myofibrils promotes the formation of a contractile protein (actomyosin), which is necessary for cardiac contraction. Cardiac glycosides normalize metabolic processes and energy metabolism in the heart muscle, increase the conjugation of oxidative phosphorylation. As a result, systole is significantly increased.

An increase in systole leads to an increase in stroke volume, more blood is ejected from the cavity of the heart into the aorta, blood pressure rises, pressure and baroreceptors are irritated, the center of the vagus nerve is reflexively excited and the rhythm of cardiac activity slows down. An important property of cardiac glycosides is their ability to lengthen diastole - it becomes longer, which creates conditions for rest and nutrition of the myocardium, and restoration of energy costs.

Cardiac glycosides are capable of inhibiting the conduction of impulses along the conduction system of the heart, as a result of which the interval between atrial and ventricular contractions lengthens. Eliminating the reflex tachycardia that occurs due to insufficient blood circulation (Weinbridge reflex), cardiac glycosides also contribute to the lengthening of diastole. In large doses, glycosides increase the automatism of the heart, can cause the formation of heterotopic foci of excitation and arrhythmia. Cardiac glycosides normalize hemodynamic parameters characterizing heart failure, while congestion is eliminated: tachycardia, shortness of breath disappear, cyanosis decreases, edema is removed. increased diuresis.

Some cardiac glycosides have a sedative effect on the central nervous system (glucosides of Adonis, lily of the valley). The diuretic effect of cardiac glycosides is mainly due to the improvement of the work of the heart, but their direct stimulating effect on kidney function is also important.

The main indications for the appointment of cardiac glycosides are acute and chronic heart failure, atrial fibrillation and flutter, paroxysmal tachycardia. An absolute contraindication is intoxication with glycosides.

With prolonged administration of glycosides, an overdose is possible (given the slow elimination and ability to accumulate). accompanied by the following symptoms. From the gastrointestinal tract - epigastric pain, nausea, vomiting: cardiac symptoms - bradycardia, tachyarrhythmia, impaired atrioventricular conduction; heartache; in severe cases - a violation of the function of the visual analyzer (violation of color vision - xanthopsia, macropsia, micropsia). Diuresis decreases, the functions of the nervous system are disturbed (excitation, hallucinations, etc.). Treatment of intoxication begins with the abolition of the glycoside. Potassium preparations are prescribed (potassium chloride, panangin, potassium orotate), since glycosides reduce the content of potassium ions in the heart muscle. Unithiol and difenin are used as antagonists of cardiac glycosides in terms of their effect on transport ATPase in complex therapy. Since cardiac glycosides increase the amount of calcium ions in the myocardium, drugs that bind these ions can be prescribed: disodium salt of ethylenediaminetetraacetic acid or citrates. To eliminate emerging arrhythmias, lidocaine, difenin, propranolol and other antiarrhythmic drugs are used.

In medical practice, various preparations from plants containing cardiac glycosides are used: galenic, neogalenic, but most widely - chemically pure glycosides, for which there is no need for biological standardization. Cardiac glycosides obtained from different plants differ from each other in pharmacodynamics and pharmacokinetics (absorption, the ability to bind to blood plasma and myocardial proteins, the rate of neutralization and excretion from the body).

One of the main glycosides of foxglove (purple) is digitoxin. Its action begins after 2-3 hours, the maximum effect is achieved after 8-12 hours and lasts up to 2-3 weeks. With repeated use, digitoxin is capable of accumulation (cumulation). Glycoside isolated from digitalis woolly digoxin, which acts faster and less long - (up to 2-4 days), accumulates in the body to a lesser extent compared to digitoxin. Even faster and shorter action celanide (isolanide, also obtained from woolly foxglove. Since digitalis preparations act relatively slowly. but for a long time, it is advisable to use them for the treatment of chronic heart failure, as well as for cardiac arrhythmias. Celanide, given its pharmacokinetics, can be administered in acute heart failure intravenously.

Spring adonis preparations ( adonizide) dissolve in lipids and water, are not completely absorbed from the gastrointestinal tract, have less activity, act faster (after 2-4 hours) and shorter (1-2 days), since they bind to blood proteins to a lesser extent. Given the pronounced calming effect, adonis preparations are prescribed for neurosis, increased excitability ( ankylosing spondylitis).

Strophanthus preparations are very soluble in water, poorly absorbed from the gastrointestinal tract, so taking them orally gives a weak, unreliable effect. They loosely bind to blood plasma proteins, the concentration of free glycosides in the blood is very high. When administered parenterally, they act quickly and powerfully, do not linger in the body. Strophanthus glycoside strophanthin administered usually intravenously (perhaps subcutaneous and intramuscular injection). The action is observed after 5-10 minutes, the duration of the effect is up to 2 days. Strofantin is used for acute heart failure that occurs with decompensated heart defects, myocardial infarction, infections, intoxications, etc.

Lily of the valley preparations are similar in pharmacodynamics and pharmacokinetics to strophanthus preparations. Korglikon contains the amount of lily of the valley glycosides, is used intravenously for acute heart failure (like strophanthin). Galenic drug - tincture of lily of the valley when taken orally, it has a weak stimulating effect on the heart and a calming effect on the central nervous system, may increase activity and toxicity

Foxglove flowers are not only unusually beautiful, but also have medicinal properties. But treatment with foxglove should be careful, because in large doses it is the strongest poison.

Such a medicinal plant as digitalis found its application in various fields. For its aesthetic appearance, the flower is used as a decorative element, and in medicine it is completely magical remedy. However, improper use of this plant can bring great harm.

Description of foxglove, varieties, legends

Digitalis- This is a medicinal plant that is shrouded in doubts, myths and legends. It is a herbaceous plant with flowers that are shaped like fingers, hence the names - foxglove (thimble). Foxglove flowers come in different colors: from bright yellow to brown.

There are several varieties of this plant - purple foxglove, woolly foxglove, large-flowered foxglove, etc. to the plantain family and has a strong effect on the human cardiovascular system.

Actively used since ancient times for the treatment of heart disease, at the wrong dose, it can cause poisoning or even death.

Digitalis is used not only for medical purposes, some of its varieties are used as an ornamental plant with beautiful large bell flowers, and in the natural environment, foxglove bells are home to insects or small rodents, food for butterflies.

There are many legends and beliefs about these plants. In some cultures, foxglove is called "Witch's Thimbles" and believe that this plant is able to protect from troubles, give good luck and health. But if you use foxglove with malicious intent using this plant, you can subdue the will of man and send misfortune to him. In fairy tales, it is believed that foxglove flowers are nothing but the hats of good fairy-tale elves.

The chemical composition of foxglove

The leaves and flowers of foxglove contain the so-called glycosides- Substances that affect the heart. Moreover, the amount and composition of these substances depends on the type of foxglove:

In foxglove purple or Digitalis contains more than 62 glycosides, among them acetyldigoxin, digoxin and gitoxin. Purple foxglove also contains choline, flavonoids and other healing substances. These chemicals enhance the work of the heart with heart failure and other diseases of the heart, blood vessels, kidneys, eyes. In therapeutic doses, they are indispensable medicines, but you should also know that these substances in the body are capable of accumulate and cause poisoning

In large doses, glycosides act as a strong poison, leading to a strong poisoning or even death. Therefore, in no case should you take digitalis preparations on your own. Prescribes and controls the intake of glycosides only doctor

foxglove rough contains a large amount of steroid and cardiotonic glycosides, lantosides, celanides. Substances of this type of foxglove are more quickly excreted from the body and accumulate less, so they are more often used. They fight congestive heart failure better, remove excess fluid from the body faster
foxglove rusty contains more than 31 glycosides, verodoxin, steroids, flavonoids. It is used to treat heart disease, as well as to treat epilepsy.

Digitalis, medicinal properties

Great Patriotic doctor and scientist Botkin said about the foxglove: "This is the scalpel of therapists" and was completely right. This plant has the strongest healing properties, but at the same time, it can harm if used incorrectly.

Digitalis and preparations that are made from it have wide spectrum of action on the human body. They apply for:

Heart disease

Heart failure - when the heart cannot provide a full blood supply to the entire body, digitalis preparations increase the release of blood from the heart, thereby helping to fight heart failure
Arrhythmias and accelerated heart rate - affecting the centers of regulation of the heart rate, restore it, and also slow down the pulse
Heart defects (congenital and acquired)

Vascular diseases:

Hypertension - reduce pressure

Eye diseases

Pain in the eyes with migraines, they are well removed with the help of digitalis preparations
Increased intraocular pressure such as glaucoma

kidney disease

With chronic kidney failure
With edema - help to remove excess fluid from the body

For lung diseases- reduce shortness of breath and increase oxygen saturation of the body

Contraindications for taking foxglove

For taking digitalis preparations, there is many contraindications. Before you start taking medicine from foxglove, be sure to consult your doctor.

Taking foxglove and its preparations without a doctor's recommendation is extremely life-threatening.

It is not recommended to use preparations containing foxglove extracts if you have:

Atherosclerosis of the coronary arteries
myocardial infarction
Complete atrioventricular block
Decreased heart rate (bradycardia)
rheumatic heart disease or endocarditis
Heart defects in the stage of compensation
Chronic lung disease
Tuberculosis
angina pectoris
Infectious diseases
Pregnancy
breastfeeding period
Digitalis preparations are also not recommended for children under 12 years of age.

Is foxglove poisonous or not?

As mentioned above, digitalis preparations have many healing properties, but if you take them without control and incorrectly, then you can get poisoning, the so-called "digitalis intoxication".

The fact is that cardiac glycosides contained in foxglove tend to accumulate in the body (cumulation effect). When they accumulate in excessive amounts, they begin act like a poison. Here are the symptoms of digitalis intoxication:

Intense abdominal pain and diarrhea
Nausea and vomiting
Rash on the skin
Interruptions in the work of the heart, sensation « heartbreak"
Slow and weak pulse
Shortness of breath, respiratory failure
Muscle twitches and cramps
hallucinations
Loss of appetite
Critical manifestation - respiratory and cardiac arrest

In history, there are cases when foxglove tincture in large doses was used as a poison. Therefore, when using drugs based on foxglove, be sure to follow all the recommendations of your doctor.

Woolly foxglove tincture

Preparations woolly foxglove contain the same active substances as other species - cardiac glycosides. They have a stimulating effect on the cardiovascular system.

From foxglove purple tincture of foxglove woolly distinguishes more rapid absorption in the body, fast effect and less accumulation capacity. Therefore, these drugs are preferred.

Woolly foxglove tincture prepared at the rate of 1 g of dry leaves per 200 ml of water. It is best to buy a ready-made tincture in a pharmacy as prescribed by a doctor.

Video: Woolly foxglove

Digitalis preparations in a pharmacy

From digitalis leaves, many industrial preparations are made in various forms of release - tablets, injection solutions, tinctures, capsules, etc. The main preparations of digitalis purpurea - digitoxin, gitoxin, cordigite.

Digitoxin- pills. Used for heart failure, hypertension, valvular heart disease, arrhythmias. It has a pronounced cumulation effect and is poorly soluble
Gytoxin- has the same therapeutic effect as digitoxin, but is much better soluble in the body and less capable of accumulation. Available as a white powder
Cordigite- a combined preparation containing digitoxin and gitoxin. Available in the form of tablets and rectal suppositories. It dissolves well in water, the cumulation effect is very low

Digoxin is one of the drugs based on digitalis.

The main dosage forms of digitalis woolly:

Digoxin- available in the form of tablets, solutions for intravenous injection and solution for oral administration. It is prescribed for valvular heart disease, arrhythmias, before surgery for patients with chronic heart disease. If necessary, this drug can be prescribed to children. The effect comes faster, the ability to accumulate is very low
Celanide- available in tablets and solutions for injection. Indications for use are the same as for other digitalis preparations, but this drug has the widest spectrum of action and less toxic effect. The ability to cumulate is very little expressed
Lantoside- Available in 15 ml dropper bottles. This drug consists of several components of foxglove, has a pronounced anti-edematous effect. The ability to accumulate is weakly expressed

Video: Digoxin. Instructions for use

Digitalis tincture - instructions for use

It should be reminded once again that you need to take foxglove only by doctor's prescription and under his strict control, strictly following all the recommendations. The exact dose, time and frequency of administration is calculated only by the doctor.

200 ml of foxglove tincture contains from 0.5 to 1 g of dry leaves of the plant. Usually adults take 20 ml 3-4 times a day.

Digitalis tincture is very easy to prepare - all you need is the flowers of the plant and alcohol.

The duration of the course of admission is also determined strictly by the doctor. No way do not cancel or renew the course on one's own.

The use of foxglove in cardiac disorders

Used for heart disease ready-made digitalis preparations. Taking homemade infusions is dangerous. The maximum amount of the drug per day should not exceed 0.5 g. The route of administration of the drug is also chosen by the doctor (tablets, intravenous injections) in each case individually.

The use of foxglove for edema

Since the substances contained in foxglove increase urine output they are used in the treatment of edema of cardiac origin. With the help of digitalis preparations, edema is treated in the complex treatment of heart failure.

Due to the increase in the amount of urine excreted, excess fluid is removed from the body and the load on the heart is relieved.

The use of foxglove in hypertension

With hypertension, foxglove infusion is used. For 200 g of boiled warm water, take 1 g of dried foxglove leaves. Insist 20-30 minutes. Take 1 tbsp. spoon 3-4 times a day. It is necessary to take digitalis tincture for hypertension only with the permission of the attending physician.

The use of foxglove for wound healing

To heal wounds, lotions from foxglove tincture are used. Apply gauze soaked in the solution to the affected area and leave for 10-15 minutes.

The use of foxglove in nervous disorders

In diseases of the nervous system, alcohol tincture of foxglove is used:

15-20 g dry leaves digitalis pour 50 ml of alcohol
then placed in a dark glass container and allowed to infuse for 7-10 days
apply no more than 10 drops of infusion at a time

Recent studies have proven that digitalis preparations can be used in the treatment of epilepsy, hysteria and other mental disorders. Also, foxglove infusion is effective for migraine attacks with pain in the eyes.

As you can see, foxglove is indeed a magical remedy for many ailments, but it should be used wisely. Otherwise, you will cause serious harm to your body, up to lethal outcome.

Video: Digitalis

Digitalis (Digitalis) is an herb from the plantain family. Distributed in the Mediterranean, found in Asia and northern Africa.

The chemical composition of foxglove

The composition of foxglove is replete with residues of organic compounds, which, in interaction with carbohydrates, form glycosides. The plant contains five of these compounds: digitoxygenin, gitoxygenin, gytaloxygenin, digoxigenin and diginatigenin.

The glycosides present in foxglove are called cardenolides or cardiac glycosides (cardiotonic glycosides). The main ones are lanatosides A, B, C.

In chemical reactions, interaction with water, glycosides form new compounds: digitoxin, acetyldigitoxin, acetylgitoxin, acetyldigoxin, gitoxin, digoxin.

The plant also contains organic acids: flavonoids (luteolin), saponins. Digitalis leaves are rich in macro- and microelements: magnesium, potassium, calcium, selenium, zinc, iron and ash.

Medicinal properties of foxglove

Foxglove has many medicinal properties. First of all, this plant helps with heart diseases such as acute heart failure.

Digitalis treats and eliminates problems in blood circulation. It is effective in hypertension and edema resulting from heart disease.

In the treatment of digitalis, unlike many drugs, does not irritate the mucous membranes of the gastrointestinal tract.

Digitalis in the composition of medicines is able to relieve shortness of breath, normalize the pulse and normalize the general condition of the body.

With the help of this herb, you can speed up the healing process of wounds.

The use of foxglove in traditional medicine

In official medicine, foxglove is used for problems with cardiac activity. Pharmacologists obtain digitoxin, gitoxin and cordinide, which are used in the preparation of medicines from the leaves of digitalis purpurea and large-flowered.

For the preparation of drugs that stimulate the heart muscle, woolly foxglove is used. The leaves of the plant contain celanide and acetyldigitoxin, which are a component of such drugs.

On the basis of digitalis or with its participation, medicines for nervous disorders, hypertension, and healing drugs are prepared.

The most famous drugs from foxglove: gitalene, digipurene, lantoside, cordigid, digitoxin.

Did you know! From some sources it follows that foxglove as a medicine was known as early as the fifth century. However, the first written mention dates back to 1543. The description is in the herbalist of the doctor Leonart Fuchs, who described the plant in detail.

Traditional medicine recipes: treatment of various diseases with foxglove

In folk medicine, medicinal decoctions and infusions of foxglove, as well as powder remedies, are widely used.

Hypertension

To prepare a remedy for hypertension pour one gram of dry, finely chopped herbs with a glass of boiling water (200 ml). Infuse the mixture for forty minutes.

Take one dessert spoon three times a day.

Important! Children can take the infusion only from the age of twelve, one teaspoonful.

Wound healing

Used for wound healing powder.Pound dry grass leaves to a powder state.

Put them on the wound. You can cover with a light bandage, preferably gauze, so that the skin breathes.

Nervous disorders

For problems with the nervous system, prepare tincture of foxglove in alcohol.Pour the dry mixture of foxglove leaves into a dark glass bottle, pour 200 ml of wine alcohol into it. Close the container tightly and insist in a dark place, shaking occasionally.

After a week, strain, pour into a clean container and store in a dark place. A single dose should not exceed thirty drops.

Heart failure

Preparing for heart failure infusion. One gram of crushed leaves is poured with hot water 200 ml. After infusion, take a teaspoon three times a day. Children prepare a less concentrated solution - 0.5 grams per 180 ml of water.

Attention! Do not self-medicate and do not take the drug for a long time. Some components accumulate in the body and can cause poisoning.

How to prepare medicinal raw materials from foxglove

Digitalis is harvested for medicinal purposes in August - September. It is advisable to harvest raw foxglove in dry weather in the evening.

Leaves cut without petiole: it has no useful elements. In the evening, foxglove contains the highest concentration of nutrients.

The leaves are dried on an industrial scale in special dryers at temperatures up to 60 degrees. During drying, the raw material is repeatedly turned over for uniform drying.

The raw material is ready when the top plate turns red. Store the product in cloth bags or cardboard containers in a dry place for 24 months.

Contraindications and possible side effects

Glycosides, which are in the composition of the herb, tend to accumulate and are slowly excreted from the body.

With prolonged use of digitalis, poisoning is possible. The foxglove plant is a powerful plant poison.

Digitalis is an ornamental herbaceous plant that belongs to the Plantain family. It is a perennial herb, but there are also biennial species of this plant. Her stem is hard, high (on average, its height is 150 cm). The leaves of the plant are lanceolate, alternate, gradually turning into leaves during inflorescence. Digitalis blooms with beautiful flowers of irregular shape. The color of the flowers varies from a delicate light yellow to a rich purple. The flowers are collected in very decorative dense beautiful inflorescences, racemes.

The flowering period falls on the middle and end of summer. The fruit of this herbaceous plant is a box with seeds. Foxglove seeds are small, brown in color, germinate well even after 3 years of proper storage. The plant is very beautiful, but its beauty is deceptive - foxglove is a very poisonous plant.

To date, approximately 35 species of foxglove are known. Most often, this beautiful medicinal plant can be found in the Mediterranean region. Some types of foxglove can be found in Europe, in the western strip of Asia and even in the northern part of the African continent. On the territory of modern CIS countries, only 4 types of foxglove grow. This plant prefers deciduous or mixed forests, light glades and edges.

Harvesting and storage

For medicinal purposes, most often, dried leaves are used. Fresh leaves are not used for medicinal purposes. Medicinal material is collected only during the flowering period of foxglove. The weather at this time must be dry. Collection is usually carried out in the afternoon, preferably before sunset. It is at this time that foxglove leaves, under the influence of heat and sunlight, contain the greatest amount of useful substances.

The collected medicinal material is dried immediately after the collection. Otherwise, the leaves lose their original color. Foxglove leaves are dried in special air or fire dryers, the temperature regime in which does not exceed +60 degrees. In the dryer, the leaves of this medicinal plant are laid out in a thin layer and constantly turned over during the drying process. Store completely dried foxglove medicinal raw materials in cardboard boxes in dry, well-ventilated areas. The maximum storage period is 24 months.

Application in everyday life

Due to its high decorative characteristics, foxglove has found its place in gardens, flowerbeds and borders. This is an indispensable component of the landscape design of a personal plot. Digitalis is one of the elements of creating such landscape compositions as an alpine hill.

Composition and medicinal properties

Digitalis contains unique trace elements, which are the basis of preparations for the complex treatment of almost all heart diseases, for example, a severe form of circulatory disorders, as well as chronic heart failure.
Preparations based on this plant are taken for puffiness, as well as for cardiac disorders.
Digitalis proved to be excellent in the treatment of shortness of breath, normalization of the pulse.
Medicines are made from foxglove that regulate the work of the heart muscle.
Powder from the dried leaves of this plant is used to heal wounds, during bouts of hysteria, and also for disorders of the central nervous system.

Application in traditional medicine

For various heart conditions

Approximately 1 g (approximately 1.4 tsp) of dry crushed foxglove leaves is poured into 1 glass of water (approximately 200 g). Insist 12 hours. Take 1 tsp. twice a day for heart disease, regardless of food intake. This infusion can be used for the complex treatment of heart diseases in children, but in this case, the concentration of the infusion should be less. 1 g of medicinal raw materials is poured not 1, but 1.5 tbsp. water.

Wound healing powder

The powder is very easy to prepare - you just need to crush the dry leaves of this plant to a powdery consistency. Apply this powder for cuts and burns, sprinkling on the sore spot.

Powder for heart disease

In addition, the powder from the leaves of this plant is taken orally for heart disease. The advantage of this medicine is that it does not have any negative effects on the liver and kidneys. Adult patients should take the powder at a dose of 0.1 g twice a day. The maximum daily dose of this drug should not exceed 0.5 g for adult patients. Store the prepared powder in a transparent glass container made of orange glass, which is tightly sealed. Shelf life - no more than 24 months (subject to sealed storage).

A decoction of foxglove leaves to regulate the work of the heart muscle

To prepare a healing decoction, you need to take 20 g of dry medicinal raw materials, pour about 600 g of boiling water over it, put on fire and boil until the amount of liquid in the dish decreases by 1/3. After that, the fire must be turned off and left to cool completely. Then the broth should be filtered. Take 1 tbsp. once a day. But the attending physician, depending on the individual parameters of the patient, can increase the dose of decoction to 2 tbsp.

Alcohol tincture for nervous disorders. Option 1

20 g of dry medicinal raw materials of foxglove should be placed in a dark glass bottle and it is poured with 200 g of wine alcohol. The bottle must be tightly sealed. Infuse for 7 days in a warm but dark place, shaking its contents from time to time. After that, the tincture should be filtered and stored in a dark glass container. A single dose of this alcohol tincture should not exceed 30 drops.

Alcohol tincture. Option 2

20 g of dry foxglove leaves should be placed in a dark glass container and pour 50 g of pure ethyl alcohol. Insist in a dark place for 7 days, shaking the contents of the container from time to time. After the expiration of this time, the infusion must be filtered. A single dose of this alcohol infusion should not exceed 15 drops, which are diluted in a small amount of boiled water immediately before use.

Contraindications

It is not necessary to use drugs based on digitalis for long-term treatment of ailments without the advice of a doctor, since this herb tends to accumulate in the body. A large concentration of glycosides in the body, which are very slowly excreted from the body, can cause symptoms of poisoning of the body.

Digitalis is a very poisonous plant, so you should not exceed the doses recommended by a specialist in order to avoid poisoning.

Symptoms of an overdose of drugs based on foxglove are blue lips, nausea, diarrhea and vomiting.

It is categorically contraindicated to take drugs based on this plant for people who suffer from coronary insufficiency, heart disease, myocardial infarction, and infectious diseases.

Do not take digitalis-based drugs along with other traditional or traditional medicines that are taken for heart disease.

Cardiac glycosides are the main group of drugs used to treat acute and chronic heart failure, in which the weakening of myocardial contractility leads to cardiac decompensation. The heart begins to expend more energy and oxygen to perform the necessary work (efficiency decreases), the ionic balance, protein and lipid metabolism are disturbed, the resources of the heart are exhausted. The stroke volume falls, followed by a violation of blood circulation, as a result of which venous pressure rises, venous congestion develops, hypoxia increases, which contributes to an increase in heart rate (tachycardia), capillary blood flow slows down, edema occurs, diuresis decreases, cyanosis and shortness of breath appear.
Pharmacodynamic effects of cardiac glycosides are due to their effect on the cardiovascular, nervous systems, kidneys and other organs.
The mechanism of cardiotonic action is associated with the effect of cardiac glycosides on metabolic processes in the myocardium. They interact with the sulfhydryl groups of the transport Na+, K+-ATPase of the cardiomyocyte membrane, reducing the activity of the enzyme. The ionic balance in the myocardium changes: the intracellular content of potassium ions decreases and the concentration of sodium ions in myofibrils increases. This contributes to an increase in the content of free calcium ions in the myocardium due to their release from the sarcoplasmic reticulum and an increase in the exchange of sodium ions with extracellular calcium ions. An increase in the content of free calcium ions in myofibrils promotes the formation of a contractile protein (actomyosin), which is necessary for cardiac contraction. Cardiac glycosides normalize metabolic processes and energy metabolism in the heart muscle, increase the conjugation of oxidative phosphorylation. As a result, systole is significantly increased.
An increase in systole leads to an increase in stroke volume, more blood is ejected from the cavity of the heart into the aorta, blood pressure rises, pressure and baroreceptors are irritated, the center of the vagus nerve is reflexively excited and the rhythm of cardiac activity slows down. An important property of cardiac glycosides is their ability to lengthen diastole - it becomes longer, which creates conditions for rest and nutrition of the myocardium, and restoration of energy costs.
Cardiac glycosides are capable of inhibiting the conduction of impulses along the conduction system of the heart, as a result of which the interval between atrial and ventricular contractions lengthens. Eliminating the reflex tachycardia that occurs due to insufficient blood circulation (Weinbridge reflex), cardiac glycosides also contribute to the lengthening of diastole. In large doses, glycosides increase the automatism of the heart, can cause the formation of heterotopic foci of excitation and arrhythmia. Cardiac glycosides normalize hemodynamic parameters characterizing heart failure, while congestion is eliminated: tachycardia, shortness of breath disappear, cyanosis decreases, edema is removed. Increased diuresis.
Some cardiac glycosides have a sedative effect on the central nervous system (glucosides of Adonis, lily of the valley). The diuretic effect of cardiac glycosides is mainly due to the improvement of the work of the heart, but their direct stimulating effect on kidney function is also important.