Digoxin - instructions for use, dose, side effects, contraindications

Cardiac glycoside from the leaves of foxglove. It has a blocking effect on the transport sodium / potassium ATP phase, after which the content of sodium ions in cardiomyocytes increases, calcium channels open, calcium enters the cells. An increase in the concentration of sodium accelerates the release of calcium from the sarcoplasmic reticulum and increases its content in the cell, thereby inhibiting the troponin complex, which inhibits the interaction of actin and myosin.The strength and speed of contraction of the cardiac muscle increases regardless of the preliminary stretching of the myocardium - the systole is shortened, becoming energetically economical. Increased myocardial contractility contributes to an increase in the shock volume of the blood.

Reduction of the end systolic and diastolic volumes of the heart together with an increase in myocardial tone reduces the size of the heart, reducing the need for myocardium in oxygen.

Carries out a negative chronotropic action, reduces the increased sympathetic activity, increasing the sensitivity of cardiopulmonary baroreceptors. Strengthening the activity of the vagus nerve, has an antiarrhythmic effect due to the elongation of the refractory period and a decrease in the rate of impulses through the atrioventricular node. The effect is improved by direct action on atrioventricular node and sympatholytic effects.

In patients with excessive stretching of the heart or with normal contractility has a direct vasoconstrictive effect. In patients with chronic heart failure, it produces mediated vasodilating effect, raises diuresis and reduces venous pressure, relieves dyspnea and swelling.

In toxic and sub-toxic doses has a positive butmotropic effect.

Pharmacokinetics:

After oral administration, an empty stomach is absorbed up to 80% in the gastrointestinal tract. The maximum concentration in the blood plasma is reached after 8-14 hours. The connection with plasma proteins is 35-40%.

The therapeutic effect develops 1-2 hours after ingestion, reaches a maximum after 8 hours, after 20-30 minutes after intravenous administration.

Penetrates through the blood-brain barrier and the placenta. Metabolism in the liver.

The half-life is 34-51 hours. Elimination by the kidneys.

Indications:

It is used to treat chronic heart failure, acute left ventricular failure, with atrial flutter, paroxysmal supraventricular tachycardia.

ICD-10

IX.I30-I52.I47.1 Nadzheludochkovaya tachycardia

IX.I30-I52.I48 Atrial fibrillation and flutter

IX.I30-I52.I50.0 Congestive heart failure

IX.I30-I52.I49.8 Other specified disorders of heart rhythm

Contraindications:

Atrioventricular block II degree, transient complete blockade, glycoside intoxication, pregnancy and lactation, individual intolerance.

Carefully:

Atrioventricular block I degree, hypertrophic subaortic stenosis, mitral stenosis, acute myocardial infarction, arteriovenous shunt, amyloidosis of the heart, pericardial tamponade, myocarditis, hypersensitivity. In the elderly, it is recommended to reduce the dosage by half.

Pregnancy and lactation:

Recommendations for FDA - Category C. Contraindicated in pregnancy and lactation.

Dosing and Administration:

Use in children

Intravenous - for rapid digitalization, depending on age:

premature neonates: 0.015-0.025 mg / kg;

term infants: 0.02-0.03 mg / kg;

from 1 month to 2 years: 0.03-0.05 mg / kg;

2-5 years: 0.025-0.035 mg / kg;

5-10 years: 0.015-0.03 mg / kg;

older than 10 years: 0.008-0.012 mg / kg.

Inside:

Up to 2 years: 0,04-0,08 mg / kg per day;

older than 2 years: 0,03-0,06 mg / kg per day.

Adults

Inside, for 0.75-1.25 mg in 2-3 divided doses, with an interval of 8 hours.

Intravenously slow or dropwise, 0.25-0.5 g.

The highest daily dose: 1.25 mg.

The highest single dose: 0.5 mg.

Side effects:

Central and peripheral nervous system: dizziness, headache, delirium, confusion.

The cardiovascular system: arrhythmia, atrioventricular blockade, rarely - thrombosis of mesenteric vessels.

Hemopoietic system: thrombocytopenic purpura, thrombocythemia.

Digestive system: anorexia, diarrhea, nausea.

Sense organs: decreased visual acuity, xanthopsia, scotoma, nasal bleeding.

Reproductive system: gynecomastia with prolonged use.

Allergic reactions.

Overdose:

Neuritis, manic-depressive psychosis, flashing "flies "before the eyes, a change in the perception of the color scale: the coloring of objects in yellow-green color, necrosis of the intestine, ventricular paroxysmal tachycardia.

Treatment is symptomatic. Dose reduction or drug cancellation.

Interaction:

Catecholamines, diuretics, calcium preparations increase glycoside intoxication.

Spironolactone, verapamil, nifedipine, quinidine increase the concentration of digoxin in the blood plasma.

Admission of antacids reduces the absorption of the drug.

Inotropic effect increases with simultaneous use with riboflavin, thiamine chloride, pyridoxine, folic acid, methionine, inosine, phosphaden, anabolic steroids.

Special instructions:

The likelihood of developing intoxication is increased in patients with impaired electrolyte metabolism (hypokalemia, hypernatremia, hypercalcemia),with obesity and in elderly patients.

The level of digitalization is determined by the plasma concentration of the drug.

In the treatment it is not recommended to drive vehicles and work with moving mechanisms.

Instructions

Digoxin (Digoxinum)