Ladyfingers – Digitalis purpurea L.

Photophilous herbaceous perennial plant height of 1.5-2 m, families norichnikovыh (Scrophulariaceae). Under natural conditions, purple foxglove grows in Central and Western Europe, North Africa. For industrial purposes the plant is cultivated in many countries.

The chemical composition of digitalis

The above-ground part of the plant contains steroidal glycosides (digitoxine, b-ацетилдигитоксин, digitonin, gatoksin, gitonin), and a number of glycosides genuiinyh purpureaglikozidy A and B), that during the drying and storage of digitalis purple converted into basic (secondary) glikozidy. Besides, The plant contains a number of organic acids, saponins, flavonoidы, choline and other compounds.

Pharmacological Properties of digitalis

Digitalis glycosides and purple differ most persistent in the body compared to other cardiac glycosides for internal application, which is explained by the presence in their molecule unusual for tissue metabolism of sugar - digitoxose. For Example, For internal use digitoksika cardiotropic effect develops only after 2-4 hours. In this regard, digitalis glycosides purple development speed cardiotropic specific activity are slowly cardiac glycosides. Besides, If cardiac glycosides cardiotonic action group continues strophanthus 24-30 hours, then digitoksina this period is 2-3 weeks.

Despite the slow absorption from the gastrointestinal tract, plant glycosides when administered gradually accumulate in the body and have a high degree of cumulation. For Example, the speed of the process of inactivation and elimination of digitoxin is so small, that its half-life (lowering plasma concentrations at 50 %) is 160 no. For the duration of the action and the ability to cumulation digitoksin ranks first among all known cardiac glycosides: follow him digoxin, celanidistrofantin.

A characteristic feature of pharmacodynamic cardiac glycosides digitalis purple, in particular digitoksina and gitoksina, It is a direct effect on the heart. This action is due to the preferential accumulation of the substance in the tissue of the heart is determined and the high sensitivity of the heart muscle of this group of medicinal compounds. Biotransformation glycosides plants takes place mainly in the liver and is characterized by successive cleavage of the molecule and glucones to aglucones (genins), and digitoxin in the liver and undergoes hydroxylation. Glycosides plants partially excreted by the kidneys, but primarily in the bile into the intestine, wherein 7-15 % digitoksina re-absorbed into the blood, causing accumulation of the drug and the possibility of intoxication. Digitoxin hardly excreted by the kidneys.

The specific pharmacological activity of digitalis glycosides and its individual exposure is determined by the general principles of cardiac glycosides on the body. It is characterized by the following main aspects of the action:

• The direct effect on cardiac muscle tissue exchange (positive, inotropic effect);
• Diastolic action (negative chronotropic effect), carried out by the central regulation vagotropic;
• The inhibitory effect on the conduction system of the heart, in particular to carry out the excitation of atrioventricular bundle.

The most important pharmacological property of cardiac glycosides, in particular, purple foxglove, they should be regarded as highly effective in terms of pathological model of heart failure. Under the influence of cardiac glycosides obscheperifericheskoe reduced vascular resistance, improves blood circulation and oxygenation process, and the blood supply to the heart muscle is improved by normalizing the overall hemodynamics.

Biological standardization of basic cardiac glycoside - purple foxglove - was carried out on various types of laboratory animals. The biological activity of the standardization digitoksina on frogs is 8000 10 ICE Ltd., -2300-2400 CUD on cats.

Toxic effects in animal experiments under the action of plant glycosides associated with overdose and their high capacity for cumulation, accompanied by cardiac and extracardiac syndromes. The animals appear arrythmia, arrhythmia, complete atrioventricular block, ventricular fibrillation, marked disorders of the gastrointestinal tract (vomiting, diarrhea) and CNS.

The use of digitalis purple medicine

Galenic purple foxglove, and herbal, containing its cardiac glycosides, used in chronic heart failure, mitral and other diseases of the cardiovascular system, accompanied by atrial fibrillation, and even small doses of digitalis translate tachysystolic form of arrhythmia in more favorable for the patient bradisistolicheskuyu form.

The greatest practical importance is the use of drugs in the digitalis purple heart diseases with symptoms of stagnation, when the heart can not cope with physiological stress. At the same time the patient is increased venous pressure, heart dilatiruetsya, increases the size of the liver, significantly reduced the level of diuresis, there are significant swelling.

Therapeutic doses of digitalis and purple lead to restoration of normal physiological activity of the heart. The effectiveness of treatment is shown to reduce the size of the heart, reducing venous pressure and increase diuresis. Patients disappear edema, normalizes the function of the liver and its dimensions. Due to the normalization of the overall hemodynamics, restore blood circulation in the tissues and normal tissue respiration in patients with significantly reduced breathlessness and cyanosis disappears. There slowing of heart rate by the central vagotroynogo effect and influence on the conductivity of atrioventricular bundle.

The duration is determined by the prescribing digitalis terms of circulation and restore normal heart rate, normalization of diuresis, the disappearance of edema and a corresponding decrease in patient weight, improving sleep and general condition. Typically, digitalis preparations prescribed long (months). During treatment it is necessary to carefully monitor the main indicators of the cardiovascular system and the general condition of the patient.

When properly used drugs naprestyanki not be observed side effects, However, it should consider the possibility of individual sensitivity of the patient.

Side effects of digitalis preparations

If overdose purple foxglove or too prolonged use of therapeutic doses may experience, severe poisoning, which are based on the selective action of cardiac glycosides heart. The main symptoms of poisoning cardiac glycosides: sharp deceleration pulse, the occurrence of arrhythmia politopnye, ʙigeminii. The appearance of bradycardia or deletions of single pulse, and a pair ekstrasistoly ("Digitalisnaâ bigeminiâ») It demands the immediate withdrawal of the drug in order to avoid a complete atrioventricular block. Sometimes an overdose of digitalis observed nausea, vomiting and a decrease in urine output. When toxic phenomena shows the use of potassium chloride, atropyna, caffeine, unitiola.

Contraindications to the appointment of digitalis: coronary insufficiency (especially when kronarnyh sclerosis heart vessels), acute myocardial infarction, vыrazhennaya bradycardia, complete atrioventricular block, active endocarditis, and rheumatic heart disease (the risk of embolism). Digitalis is not indicated in compensated heart diseases.

Caution should be used when digitalis preparations aortal (especially stenosis), accompanied by persistent bradycardia. If bradycardia, developing from small doses of digitalis, the drug can be administered together with belladonna.

Formulations, Dosage and administration of digitalis

The powder from the leaves of purple foxglove (Pulverized leaves of Digitalis). Crushed leaves with handle, powder green. Active 50-66 in ICE 1 g. Assign an adult on the inside of 0.05-0.1 g per reception 2-3 times a day. It may also be administered in the candlelight. Children under 1 Year appoint 0.005-0.01 g; from 2 to 5 years - 0.02-0.03 g; from 6 to 12 years - 0.03-0.06 g per reception.

Higher doses for adults: single 0,1 g, daily 0,5 g.

Higher doses for children:

• aged 6 month - single 0,005 g, daily 0,02 g;
• from 6 Months before 1 year - single 0,01 g, daily 0,04 g;
• aged 2 s - single 0,02 g; daily 0,08 g;
• 3-4 Years - single 0,03 g, daily 0,12 g;
• 5-6 Years mult 0,04 g, daily 0,16 g;
• 7-9 Years - single 0,05 g, daily 0,2 g;
• 10-14 Years - single 0,05-0,075 g, daily 0.2-0.3 g.

Available in powder and tablets, containing 0,05 grams of digitalis. Keep powder with caution.

Infusion of the leaves of the foxglove (Digitalis infused leaf) prepared at the rate of 0.5-1 g leaves on 180 ml of water. Assign an adult to 1 tablespoon 3-4 times a day. For children prepare an infusion of 0.1-0.4 g 100 ml; give on 1 tea - 1 dessert spoon 3-4 times a day. The infusion can be administered as enemas.

Digitoxine (Digitoxinum) is the most active digitalis glycosides and purple, and is a white powder, consisting of colorless, Rectangular crystals bitter taste, sparingly soluble in water, well - alcohol.

One of the most important advantages over other drugs digitoksina purple foxglove is it always the same activity, not changing the storage. As a result, it is dosed gravimetrically and does not require biological activity of standardization specification. Within 25 minutes after administration digitoxin manifests its action, The maximum effect is observed after 4-12 hours.

Under the influence of the drug in the myocardium is a change of energy processes, thereby increasing the force of contraction of the heart muscle, systole is shorter and stronger, and diastole lengthens, improving diastolic filling of the ventricles. An important advantage over other digitoksina cardiac glycosides, especially from other species Digitalis (woolly, resnitchatoy) and strophanthus, It is an expression of the ability of heart rate slows.

In patients with circulatory failure atrial tachyarrhythmia becomes bradyarrhythmia, disappear or significantly reduced pulse deficit, It increases the speed of blood flow in large, and in the pulmonary circulation, decreases venous pressure, daily urine output is significantly increased, and body weight decreases. Digitoxin has an effect on blood vessels, whereby kidney vessels, skin, muscles expand, vessels and areas, innervated by the splanchnic nerve, taper. This leads to a redistribution of the mass of blood in various organs and tissues.

Improved hemodynamic and renal vasodilation cause a pronounced diuretic effect of the drug. Gradually, the number of normal blood circulation. As a result of the shortening of the systole and diastole lengthening increases coronary blood flow.

Compared with other cardiac glycosides digitoxin most strongly binds with serum albumin, that, along with its slow elimination from the body causes the cumulation, It expressed this preparation mostly, than other cardiac glycosides. High ability to cumulation digitoksina requires careful control of its action.

Digitoxin prescribed for chronic heart failure of various etiologies (heart disease, kardioskleroz, hypertonic disease, myocardial dystrophy), it can be used in acute heart failure. The most effective drug for diseases, accompanied by atrial tachyarrhythmia and in some forms of paroksiz- mal tachycardia, as well as circulatory insufficiency stage II. Satisfactory results are observed in stage III disease, often in cases, when other drugs (strofantin) ineffective.

Digitoxin appointed interior. Due to the high ability of the drug to cumulation digitoxin treatment should be substantially individualized. However, there Regimen. The most common:

• 1 day 6-8 tablets 0,1 mg (4 tablets immediately, 1-2 tablets every 6-8 hours);
• 2-second and third day, 4-5 tablets.

Upon the occurrence of the desired effect (dyspnea, slow pulse, ecuresis) maintenance dose administered to the patient (1 tablet per day); sometimes alternate: one day - 2 tablets, the other - 1 tablet.

There is another scheme of the drug: 5-6 Tablets a day for 3 days, and then the maintenance dose - 1-2 tablets a day. In some cases enough 1 tablets per day.

Side effects and contraindications of drugs for common purple foxglove. It will be appreciated (possibility of hypersensitivity to the drug; due to its high ability to cumulation some researchers recommend the use of digitoxin only in hospital.

Gitoksin (Gitoxinum) - Fine-grained white powder bitter taste, insoluble in water, it is soluble in alcohol. Melting point 263-265 ° C. IN 1 Mr. gitoksina contained 1000 KED, or 8330 LED. According to the degree of biological activity of the drug close to digitoksin, but slightly inferior to him: 1 CUD digitoksina matches 0,42 mg, and 1 QED - gitoksina - 1 mg. However, the biological activity of drugs in determining almost identical to frogs. Gitoksin not destroyed by ingestion, rapidly and completely absorbed, well koumouliruet, more yielding in this digitoksin, It does not irritate the mucous membranes of the gastrointestinal tract. Activity did not change during storage.

The drug has a pronounced cardiotonic action, manifested in shortening and strengthening the systole, lengthening diastole, helps slow the heart rate.

Prescribed the drug for heart failure stage II and III of various etiologies; it is recommended to use the drug mainly in the forms, accompanied by atrial tachyarrhythmia.

Gitoksin appointed interior, since 0,0003-0,0004 g / day with subsequent dose reduction to 0,0002-0,0001 g / day. After reaching effects the maintenance dose is adjusted individually, that patients take a long time.

Possible complications and precautions are the same, how the use of other drugs digitalis.

Kordigit (Cordigitum) - Novogalenovyh preparation of dry leaves and purple foxglove, containing an amount of glycosides (gitoksin and digitoxin). Slightly yellow amorphous powder, it is soluble in water, easy - in chloroform, alcohol, acetone, insoluble in petroleum ether.

In appointing kordigita therapeutic effect observed in the 1st day, even in severe stagnation (The sharp increase in liver, ascites). Action kordigita is similar to the net digitoksina, which absorbed almost 100 % regardless of the severity of stagnation.

When using kordigita quickly noted the impact of systolic digitoksina, It slows the rhythm, eliminated pulse deficit, increased diuresis. When you remove the drug bradycardia disappears in 2-4 days, what, apparently, It is due to the rapid termination of gitoksina, a member of the kordigita, which is less absorbability, at cumulation, more rapid elimination from the body, than pure digitoxin, and relatively quickly converted by the liver to the inactive aglycone.

The therapeutic effect is especially pronounced when kordigita tachysystolic atrial fibrillation, atrial flutter to the blockade of 2:1, when thyrotoxic heart damage. However, the sensitivity to kordigitu may vary within rather wide limits, and the dosage should be strictly and ndividualnoy.

The drug is prescribed inside of 0,5-1 tablet 2-4 times a day. IN 1 tablet contains 0,0008 g active glycosides, that corresponds in activity 0,1 Mr. standardized leaf foxglove.

Contraindications common to a group of drugs purple foxglove.

Available in tablets, containing 0,0008 g (0,8 mg), and candles, containing 0,0008 Mr. kordigita.