Perennial (biennial in culture) herbaceous plant of the morning glory family. The stem is straight, little branched, mostly dark purple, 60-150 cm tall. Basal and lower stem leaves are 5—12 (20) cm long and 1.5—3.5 cm wide, oblong-ovate, covered, like the upper stem leaves, with glandular hairs, mostly entire, rarely slightly wavy or finely toothed along the edge; upper stem leaves are lanceolate, 4-10 cm long, sessile, sharp, gradually decreasing and turning into bracts. The flowers are bisexual, irregular, on short peduncles in the axils of elongated lanceolate bracts, collected in a pyramidal, long, dense, versatile cluster. Corolla tubular-bell-shaped, 20-30 mm long, short-lobed; corolla tube spherically inflated, brown-yellow, with purple veins; the upper lip is shallowly dissected into two triangular, blades bent upwards, the lower lip with small, triangular, lateral, outwardly bent blades, with a large white or reddish blade-shaped middle blade, almost equal to the tube of the corolla. The fruit is a two-nest box. Blooms in July – August.
Spread. Foxglove 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 foxglove contain 0.5-1% cardiac glycosides, the main ones being lanatosides A, B and C (in the process of drying and storage, due to the action of enzymes, lanatosides A, B and C are transformed into secondary, more stable glycosides – digitoxin, gitoxin and digoxin ). A small amount of leaves also contains other glycosides: lanatosides D and E, strospeside, odoroside, gitorin, glucogitorin, verodoxin, etc. In addition, the leaf contains steroid saponins digitonin and tigonin.
Pharmacological properties and use . The active substances of digitalis are cardiac glycosides. Among the individual glycosides, digoxin, lanatoside C (celanide) and acetyl digitoxin are used in medical practice, and the new galena product lantoside is an alcohol solution of a sum of glycosides isolated from plant leaves. In terms of physiological effect, digitalis woolly glycosides are close to digitalis purple glycosides; their main difference is a slightly faster absorption, a smaller cumulative effect, a more pronounced diuretic effect. Due to the toxicity of foxglove, it is treated by a doctor. Self-medication is dangerous!
Medicinal forms and applications.
Digoxin (Digoxinum) is prescribed orally and parenterally (intravenously) to stop attacks of paroxysmal tachycardia and in severe forms of circulatory disorders. Digoxin is given inside on the 1st day at 0.25 mg (1 tablet) 4-5 times at equal intervals of time (1-1.25 mg per day), and on the following days – at 0.25 mg 3-1 times day. The dose is adjusted daily, guided by indicators of electrocardiograms, respiration and diuresis. Depending on the effect, the dose is repeated or gradually reduced. After achieving the necessary therapeutic effect, they switch to treatment with maintenance doses: 0.5-0.25-0.125 mg per day. Doses for children should be selected strictly individually. Approximately for “saturation” the product is used at the rate of 0.05-0.08 mg/kg and this amount is administered in 1-2 days (rapid digitalization method) or in 3-5 days, and with slow “saturation” – in 6-7 days. Adults are prescribed intravenous digoxin in a dose of 0.25-0.5 mg (slowly administered in 10-20 ml of 20% or 40% glucose solution or isotonic sodium chloride solution). In the first days, they inject 1-2 times a day, in the next 4-5 days – 1 time a day, after which they switch to taking the product orally in maintenance doses. The highest daily dose of digoxin for adults is 1.5 mg. In patients with renal failure, the dose of digoxin is reduced by approximately two times. Celanid (Celanidum) is prescribed orally and intravenously for acute and chronic circulatory failure of the 2nd and 3rd degrees, tachysystolic form of atrial fibrillation and supraventricular form of paroxysmal tachycardia. It is given inside, starting with 0.25-0.5 mg (1-2 tablets) or 10-25 drops of 0, 05% solution 3-4 times a day. After achieving a therapeutic effect (on the 2nd-3rd day with intravenous administration or on the 3-5th day with oral administration), the daily dose is reduced to the maintenance one: 0.4-0.2 mg (2-1 ml of 0.02% solution) intravenously or 0.5-0.25 mg (2-1 tablet) or 40-20-10 drops of 0.05% solution orally. For long-term maintenance therapy, half a tablet is prescribed internally twice a day. The highest doses for adults inside: single — 0.0005 (0.5 mg), daily — 0.001 g (1 mg); into a vein: single — 0.0004 g (0.4 mg), daily — 0.0008 g (0.8 mg). 05% solution inside. For long-term maintenance therapy, half a tablet is prescribed internally twice a day. The highest doses for adults inside: single — 0.0005 (0.5 mg), daily — 0.001 g (1 mg); into a vein: single — 0.0004 g (0.4 mg), daily — 0.0008 g (0.8 mg). 05% solution inside. For long-term maintenance therapy, half a tablet is prescribed internally twice a day. The highest doses for adults inside: single — 0.0005 (0.5 mg), daily — 0.001 g (1 mg); into a vein: single — 0.0004 g (0.4 mg), daily — 0.0008 g (0.8 mg).
Acetyldigitoxinum is prescribed orally and intravenously for the same diseases as celanid. 0.4-0.8 mg (2-4 tablets of 0.2 mg each) per day are given inside in the first 3-5 days, then the dose is reduced (depending on the effect) to 0.3-0.2-0, 1 mg per day. 2-4 ml of 0.01% solution is injected intravenously (injected slowly in 10 ml of isotonic sodium chloride solution or dropwise in 5% glucose solution). After receiving the therapeutic effect, they switch to taking the drug orally.
Lantoside (Lantosidum) is used mainly in outpatient practice for supportive therapy in chronic circulatory failure of the 1st, 2nd and 3rd degrees, accompanied by tachycardia, tachyarrhythmia and atrial fibrillation. 15-20 drops are given inside 2-3 times a day. In case of impossibility of oral administration (when dyspeptic phenomena occur), the product is prescribed rectally in enemas (20-30 drops in 20 ml of isotonic sodium chloride solution). The highest doses for adults inside: single — 25 drops, daily — 75 drops. Contraindications for digitalis wool products are the same as for digitalis purple products.