A biennial herbaceous plant of the morning glory family. The stem is straight, sparsely branched, rarely simple, gray-pilose, 50-150 cm tall. The leaves are simple, toothed and notched along the edge, wrinkled, covered with soft hairs on both sides; basal leaves on long winged petioles, ovate or ovate-lanceolate, sharp, 12-20 (30) cm long and 3-7 cm wide, collected in a rosette; stem leaves — alternate; the lower ones are petiolate, the upper ones are sessile and gradually turn into bracts. The flowers are bisexual, irregular, drooping, sitting in the axils of bracts one at a time and forming a one-sided cluster 50-80 cm long or more. The corolla is double-lipped, tubular-bell-shaped, 4-5 cm long and 2-3 cm wide, purple on the outside, rarely pink or white, on the inner surface it has dark red spots with a white border; upper lip wide, short, rounded, whole or slightly notched, the lower one is three-lobed (the middle blade is elongated, on the inner side – with a tuft of thick long hairs). The fruit is a two-nest box. Blooms in June – July.
Distribution . Digitalis purple is grown in specialized state farms as a medicinal plant.
Procurement and storage . Foxglove leaves (Folium Digitalis purpureae) are used to make medicines. Raw material (without petioles) is collected twice a year: for plants of the first year of vegetation — at the end of summer (when the leaves reach the standard length of 20 cm) and in autumn (no later than September), and for plants of the second year of vegetation — in the phase of shoot formation and in the phase of mass flowering. The collected leaves are quickly dried in dryers first at a temperature of 55-60 ° (30 minutes), and then dried at a temperature of 40 °. 20-22% of dry leaves are obtained. The finished raw material must be stored in a dry (!) room (when moistened, the biological activity of the raw material decreases) without access to light. The shelf life is 2 years (subject to annual review!).
Chemical composition . The leaves of digitalis purpura contain cardiac glycosides (purpureaglycosides A and B, which during drying and storage are transformed into digitoxin and gitoxin, respectively, due to the action of enzymes), steroid saponins (digitonin, digonin, gitonin), flavonoids (luteolin, 7-glycoside luteolin), choline, organic acids and other compounds.
Pharmacological properties and use. The active substances of digitalis purpurea are cardiac glycosides. The most active therapeutic role belongs to digitoxin and gitoxin. The peculiarity of the glycosides of digitalis purpurea (this applies equally to other types of digitalis) is their ability to increase the contraction of the heart muscle, while simultaneously reducing their number, which contributes, on the one hand, to better rest of the heart, and on the other hand, to its greater blood flow. This leads to an increase in the volume of blood pushed into the aorta, an acceleration of blood flow, and a decrease in venous pressure. As a result of the normalization of hemodynamics and the expansion of renal vessels, urination significantly increases, which leads to the disappearance or reduction of edema. According to their physical and chemical properties, digitalis glycosides belong to the group of lipophilic glycosides. They are well absorbed and do not break down in the gastrointestinal tract, they quickly interact with plasma proteins, so they are quite effective when taken orally (in case of impossibility of administration into the stomach, for example, when vomiting, they are administered rectally), their effect begins to manifest through 2-4 hours, reaches a maximum after 8-12 hours, and stops completely after 14-21 days. Violation of the excretory function of the kidneys has little effect on the excretion of glycosides, since they are excreted in urine in small quantities. After absorption in the intestines, a significant amount of them enters the liver and is excreted with bile, and then reabsorbed again in the gastrointestinal tract. The simultaneous presence of the noted properties gives the full right to call digitalis “the king of heart remedies.” Indications for prescribing drugs are chronic heart failure of various origins, paroxysmal tachycardia. It should be remembered that digitalis products have a high cumulative capacity and toxicity, and therefore they can be taken only as prescribed by a doctor.
Medicinal forms and applications .
Powder from the leaves of purple foxglove (Pulvis foliorum Digitalis) is prescribed internally for adults at 0.05-0.1 g per dose 3-4 times a day (after achieving the required effect – slowing down the pulse, increasing urination, reducing shortness of breath – a maintenance dose is prescribed, which selected individually). Children are prescribed from 0.005 to 0.06 g per reception depending on age: up to 1 year – 0.005-0.01 g each; from 2 to 5 years – 0.02-0.03 g each; from 6 to 12 years – 0.03-0.06 g per reception. The highest doses for adults: single 0.1 g, daily 0.5.
The highest doses for children: under the age of 6 months — a single 0.005 g daily — 0.02 g; from 6 months to 1 year — single 0.01 g, daily — 0.04 g; aged 2 years — single 0.02 g, daily — 0.08 g; 3-4 years — single 0.03 g, daily — 0.12 g; 5-6 years old — single 0.04 g, daily — 0.16 g; 7-9 years old — one-time 0.05 g, daily — 0.2 g; 10-14 years – single 0.05-0.075 g, daily – 0.2-0.3 g. In case of impossibility of oral intake, the product is prescribed rectally in suppositories.
Infusion of foxglove leaves (Infusum foliorum Digitalis) — 0.5-1 g of raw material per 180 ml of water, prescribed 1 tablespoon 3-4 times a day. An infusion for children is prepared at the rate of 0.1-0.4 g of leaves per 100 ml of water and given 1 teaspoon – 1 dessert spoon 3-4 times a day. In case of impossibility of oral intake, the infusion is prescribed rectally in enemas. Digitoxin (Digitoxinum) is prescribed internally in the form of tablets containing 0.1 mg of the product. Due to the high cumulative ability of digitoxin, treatment with this product is carried out taking into account the individual characteristics of each patient. At the same time, there are generally accepted schemes for the use of digitoxin. The most used of them is as follows: on the 1st day — 6—8 tablets of 0.1 mg (4 tablets at once and 1—2 tablets every 6—8 hours), on the 2nd and 3rd days — 4 – 5 tablets. After achieving the required effect (slowing down the pulse, increasing urination, reducing shortness of breath), a maintenance dose is prescribed (1 tablet per day or alternating: one day — 2 tablets, the second day — 1 tablet). Patients with symptoms of dyspepsia or stasis in the portal vein are prescribed digitoxin in suppositories (Suppositoria Digitoxini 0.00015). 1-2 suppositories are injected into the rectum 1-2 times a day during the first 2-5 days, followed by a dose reduction to 1-2 suppositories per day (the dose must be selected individually!). The highest doses of digitoxin for adults inside: single — 0.5 mg, daily — 1 mg. Patients with symptoms of dyspepsia or stasis in the portal vein are prescribed digitoxin in suppositories (Suppositoria Digitoxini 0.00015). 1-2 suppositories are injected into the rectum 1-2 times a day during the first 2-5 days, followed by a dose reduction to 1-2 suppositories per day (the dose must be chosen individually!). The highest doses of digitoxin for adults inside: single — 0.5 mg, daily — 1 mg. Patients with symptoms of dyspepsia or stasis in the portal vein are prescribed digitoxin in suppositories (Suppositoria Digitoxini 0.00015). 1-2 suppositories are injected into the rectum 1-2 times a day during the first 2-5 days, followed by a dose reduction to 1-2 suppositories per day (the dose must be chosen individually!). The highest doses of digitoxin for adults inside: single — 0.5 mg, daily — 1 mg.
Gitoxinum is prescribed internally, starting with 0.0002-0.0004 g per day, followed by a dose reduction to 0.0002-0.0001 g per day. After achieving the desired effect, an individual maintenance dose is selected. Cordigit (Cordigitum) is prescribed internally for 1/2-1 tablet 2-4 times a day or 1 suppository 1-2 times a day. The cumulative effect of cordigite is much smaller than that of digitoxin. Taking digitalis products is contraindicated in case of organic changes in the heart, in particular in the case of degeneration of the heart muscle and pronounced atherosclerosis, as well as in case of endocarditis with a tendency to embolism.