Therapy of thrombosis and thromboembolism is not complete without anticoagulants, which include low molecular weight heparins. These substances in the composition of medicines change blood clotting, thereby restoring vascular patency.
Varieties of direct anticoagulants
Given the mechanism of action of antithrombotic compounds, it can be noted that they come with direct and indirect action. The first group of substances is most commonly used.
Anticoagulants of direct influence are divided into low molecular weight and unfractionated heparins according to their structure. They can also be direct inhibitors of thrombin, such as hirudin.
Characteristics of low molecular weight heparins
They are otherwise called fractionated compounds, in which the molecular average weight ranges from 4000 to 6000 d altons. Their activity is associated with mediated inhibition of the formation and activity of the thrombin enzyme. Heparin has such an effect on blood clotting factor Xa. The result is an anticoagulant and antithrombotic effect.
Low molecular weight heparins are obtained from unfractionated substances isolated from the intestinal epithelium of a pig, during a chemical or enzymatic depolymerization process. As a result of this reaction, the polysaccharide chain is shortened by a third of its original length, which helps to reduce the anticoagulant molecule.
There are different low molecular weight heparins, the classification of which is based on methods for obtaining s alt-containing compounds.
Issue Forms
Preparations based on them are injectable solutions for subcutaneous or intravenous administration. They are usually packaged in ampoules or syringes for single use.
Low molecular weight heparins are not produced in tablets.
Intramuscular drugs are not used.
Description of the drug "Gemapaxan"
Refers to direct acting anticoagulant drugs. The active ingredient is enoxaparin in the form of a sodium s alt, which is considered a derivative of heparin. This modification provides high adsorption when injected subcutaneously and low individual sensitivity.
Produced by the Italian company Italfarmaco S.p. A. in the form of a clear, colorless or light yellow solution for injection, packaged in syringes of 0, 2, 0, 4 or 0.6 ml.
Dosages of enoxaparin sodium are 2000 IU in 20 mg; 4000 IU in 40 mg and 6000 IU in 60 mg. The active ingredient of the drug is dissolved in injection water. Sodium enoxaparin exhibits a high dosage of 100 IU per 1 mgan inhibitory effect on blood coagulation factor Xa and a low effect on antithrombin at a dose of 28 IU per 1 mg.
The use of the therapeutic concentration of the drug in various diseases does not lead to an increase in the duration of blood loss.
Prophylactic sodium enoxaparin dosage does not change partially activated thromboplastin time, does not disturb platelet aggregation and the process of their connection with fibrinogen molecules.
Low molecular weight heparins in a higher concentration of drugs (6000 IU in 0.6 ml) are used:
- for the treatment of deep vein thrombosis;
- with angina pectoris forms of unstable and infarcted condition of the myocardial muscle in combination with acetylsalicylic acid;
- for the prevention of increased coagulation during the period of the hemodialysis procedure.
Administration of a subcutaneous solution with a dosage of 2000 and 4000 IU per 0.2 and 0.4 ml, respectively, is used to prevent thrombosis and thromboembolic conditions of the venous system:
- during orthopedic surgery;
- bed patients with insufficiency of chronic respiratory apparatus or cardiac system types 3 and 4;
- in acute infectious or rheumatic diseases when there is a risk factor for blood clots;
- elderly patients;
- with excessive fat deposition;
- with hormone therapy.
The drug is used subcutaneously into the abdominal wall, in its postero- and anterolateral zone.
The drug is contraindicated in thrombocytopenia, bleeding, coagulation disorders, peptic ulcer of the gastric mucosa and duodenal ulcer, subacute bacterial endocarditis, diabetes mellitus, hypersensitivity and pregnancy.
Hemapaxan medicine: price
The cost of an injection solution containing 2000 IU per 0.2 ml in a syringe for six pieces is 955 rubles.
For a larger dosage of Hemapaksan, the price fluctuates within 1,500 rubles for a pack of six syringes.
Description of the drug "Clexane"
Refers to similar products based on enoxaparin sodium. It is produced by the French company Sanofi Aventis as an injectable clear solution, which can be colorless or with a slightly yellow tint.
There are dosages of the drug "Clexane" of 10000, 8000, 6000, 4000 and 2000 IU of enoxaparin sodium in 1, 0; 0.8; 0.6; 0.4; 0.2 ml of medicinal liquid, respectively. The content of the active ingredient in 1 mg of solution is 1000 IU.
Low molecular weight heparins are produced in glass syringes, which can be 2 or 10 pieces in a pack.
The drug "Clexane" is used to prevent thrombotic and thromboembolic disorders in the veins during surgical intervention related to orthopedics and hemodialysis.
The solution is administered subcutaneously to eliminate the thrombotic condition in the deep veins and in the arteries of the lung.
The drug treats angina pectorisunstable nature and myocardial muscle infarction in combination with Aspirin tablets.
Clexane medicine: price
The cost of an injection solution containing 2000 IU per 0.2 ml for one syringe is 175 rubles.
For one unit with a dosage of 4000 IU for 0.4 ml you will have to pay 280 rubles, for 6000 IU for 0.6 ml - 440 rubles, for 8000 IU for 0.8 ml - 495 rubles.
For the drug "Clexane" the price for a package of 10 pieces with a dose of 20 mg, 40 mg and 80 mg is 1685, 2750, 4000 rubles.
Description of the drug "Fragmin"
The active ingredient of this drug is a heparin-derived substance represented by sodium d alteparin. It is obtained by depolymerization under the action of nitrous acid, followed by purification using ion exchange chromatography. Sodium d alteparin s alt includes sulphated polysaccharide chains with an average molecular weight of five thousand d altons.
Auxiliary components are water for injection and sodium chloride s alt. The Belgian drug "Fragmin" is described by the instruction as a solution for injection of subcutaneous and intravenous administration in the form of a transparent liquid, without color or with a yellowish tinge.
It is produced in single-dose glass syringes of 2500 IU in 0.2 ml; 5000 IU in 0.2 ml; 7500 IU in 0.3 ml; 10,000 IU in 1.0 ml; 12500 IU in 0.5 ml; 15,000 IU in 0.6 ml; 18000 IU in 0.72 ml.
The drug "Fragmin" instruction recommends using it as a preventive measure to control the mechanismblood clotting in hemodialysis and hemofiltration measures aimed at the treatment of kidney failure, to prevent the formation of clots in surgery.
The drug is administered to eliminate thromboembolic lesions of bedridden patients.
The solution is used to treat unstable angina pectoris and infarction of the myocardial muscle, symptomatic venous thromboembolism.
Description of the drug "Anfibra"
It is classified as a low molecular weight heparin of the Russian company JSC "Veropharm". Available as a clear solution for injection, which may be colorless or yellowish.
The product is based on the sodium s alt of enoxaparin, which can contain 2000 IU in 0.2 ml; 4000 IU in 0.4 ml; 6000 IU in 0.6 ml; 8000 IU in 0.8 ml; 10,000 IU in 1.0 ml. Distilled water is used as a solvent.
Packed in ampoules or syringes of 1 ml, which are packed in carton packs of 2, 5 and 10 pieces.
The instruction recommends using the Anfibra drug to prevent the development of a thromboembolic state during surgical procedures and hemodialysis, in the treatment of clot formation in deep vessels.
The solution is used to treat unstable angina pectoris and infarction of the heart muscle, in which there is no Q wave on the electrocardiogram.
Description of Fraxiparine
Calcium nadroparin belongs to low molecular weight heparins, which is obtained during the depolymerization process. Its molecules are glycosaminoglycans,whose average molecular weight is 4300 d altons.
Fraksiparin (subcutaneous injections) contains calcium hydroxide and nadroparin s alt, which are dissolved in injection water.
The dosage of the active ingredient is 2850 IU in 0.3 ml; 3800 ME in 0.4 ml; 5700 IU in 0.6 ml, 7600 IU in 0.8 ml, 9500 IU in 1 ml.
The drug is a clear or slightly opalescent liquid that has a light yellow tint or is completely colorless.
Nadroparin s alt binds well to antithrombin protein III, which causes accelerated inhibition of factor Xa. The substance activates an inhibitor that ensures the conversion of tissue factor, reduces blood viscosity and increases the membrane permeability of platelet and granulocyte cells. This is how the antithrombotic effect of the drug is carried out.
Fraxiparine injections are prescribed to prevent thromboembolic conditions during orthopedic surgical procedures and hemodialysis. The drug is administered to patients with a high risk of blood clots, acute respiratory and cardiac failure, unstable angina, myocardial infarction with no Q-wave.
Use of anticoagulants in childbearing
Low molecular weight heparins during pregnancy are prescribed to patients with blood clotting disorders so that a placental thrombus does not form, which will lead to abortion, to a pre-eclamptic state with high bloodpressure, detachment of the child's place with heavy bleeding, slow growth of the fetus in the uterus, which will cause a low birth weight of the baby.
Such anticoagulants are prescribed for women in position with a possible risk of clots in deep veins, for example, in the lower extremities, as well as blockage of the artery of the lung.
Therapy with low molecular weight heparins is a painful process in which a pregnant patient injects the drug daily under the skin on the abdomen.
However, in the course of clinical randomized trials, results have been obtained that prove that often the use of such anticoagulants does not contribute to a positive effect. It was also found that low molecular weight heparin therapy can harm the mother's body, associated with an increase in bleeding and a decrease in labor pain relief.
Study data have shown that stopping anticoagulant treatment can save many women from unnecessary pain during pregnancy.
In the instructions for the use of drugs based on low molecular weight heparin, therapy during pregnancy is contraindicated.
