Cardiovascular diseases occupy a leading position among the pathologies leading to disability and early mortality among the population. It is for this reason that modern pharmacology pays special attention to drugs aimed at thinning the blood and preventing the formation of blood clots in the vessels and arteries. In this regard, drugs from the group of anticoagulants deserve special attention. What is anticoagulant therapy, what are its pros and cons, we learn from this publication.

The essence of anticoagulant treatment

Anticoagulant therapy is an effective treatment for varicose veins, deep vein thrombosis, pulmonary embolism, heart attacks and strokes. The active substances of anticoagulants perfectly thin the blood and prevent its clotting, due to which a therapeutic and prophylactic effect is achieved. Such drugs are highly effective and can be used for a long time without harm to health, which has influenced their wide popularity among doctors and patients.

Who is prescribed anticoagulant therapy

Preparations from the group of anticoagulants are prescribed for the prevention and treatment of thrombosis provoked by the following pathological conditions:

• development of an aneurysm of the left ventricle;
• operations on the heart or blood vessels;
• thromboangiitis obliterans;
• obliterating endarteritis;
• thromboembolism of the pulmonary arteries;
• thrombophlebitis of superficial veins on the legs;
• phlebeurysm;
• angina;
• myocardial infarction;
• flickering arrhythmia.

Often, blood clots appear in the deep veins of the legs, causing redness and swelling of the lower extremities. However, this is not the biggest trouble associated with the formation of a blood clot. It is much more dangerous when the separated blood clot with the blood flow enters the lungs. In this case, a pulmonary embolism develops. This condition leads to severe shortness of breath and a drop in blood pressure. Pulmonary embolism requires urgent medical attention, as it can threaten the life of the patient. Taking anticoagulants helps prevent this problem by preventing the development of an embolism.

Another indication for the use of anticoagulants is to prevent the development of thrombosis in the vessels of the heart. This is especially true for people suffering from heart rhythm disturbances, i.e. atrial fibrillation. Finally, a separated fragment of a blood clot can enter the vessels of the brain, provoking the development of a stroke. Properly selected blood thinners also save from such severe consequences.

Types of anticoagulants

In all of these cases, doctors prescribe anticoagulants, and, depending on the existing ailment, direct anticoagulants or vitamin K antagonists (indirect anticoagulants) may be prescribed. Let's consider both types.

Indirect drugs

Indirect anticoagulants disrupt the production of substances responsible for blood clotting. Such funds begin to act after a few days, as they have a cumulative effect, and the duration of their action ranges from 5 days to 15 days.

The most popular indirect blood thinners are medicines based on sodium warfarin, primarily Warfarin. It begins to act at least 7 days after the first dose of the medicine. True, it is impossible to take such a remedy without a doctor's prescription, because only a specialist will be able to calculate the exact dosage of the drug, thereby saving the patient from a lot of side effects. The disadvantages of this tool include the need to constantly monitor the state of the blood and, according to the results of the tests, adjust the dosage. We also note that today Warfarin is the best drug to combat ischemic stroke.

Other indirect anticoagulants include coumarin derivatives such as Dicoumarol, Sincumar and Acenocoumarol. These funds are less popular than Warfarin, although their principle of action is absolutely identical.

By the way, while taking vitamin K antagonists, you should stop eating foods rich in this vitamin (sorrel and seaweed, spinach and green tea, lentils and onions) so as not to disrupt the effect of the drug.

Direct acting drugs

Until 2010, Warfarin and its analogues were the only drugs approved for use by the WHO. However, over the past few years, a worthy alternative to these drugs has appeared on the pharmacological market. They are called PPA, that is, oral direct anticoagulants.

The popularity of these drugs is growing day by day, and all because direct-acting anticoagulants have many advantages over their predecessors. In particular:

• begin to act immediately after application (which is much more effective than taking Warfarin, the effect of which appears only after a week, and for the prevention of venous thrombosis it is very long);
• have specific antidotes (which has a positive effect in the treatment of acute ischemic stroke);
• have a fixed dosage that does not need to be specially selected and constantly adjusted;
• the food taken does not affect the dosage of the drug;
• there is no need for regular blood monitoring.

Direct anticoagulants include drugs whose active ingredient is heparin (Fraxisparin and Fragmin, Troparin and Clivarin) or hirudin (Arikstra, Exantha and Melagatran).

It is obvious that taking such drugs is easier, and besides, there is no need for constant blood monitoring. However, skipping such anticoagulants is extremely dangerous, since in this case there is a high risk of developing thrombosis or inadequate anticoagulation.

Is it possible to combine two types of anticoagulants?

As can be understood from the above, anticoagulants are a real salvation for a person in case of angina pectoris, heart attacks, vascular embolism, varicose veins or thrombophlebitis. Moreover, in the case of an acute condition, direct-acting drugs are prescribed, which give an immediate effect. If the therapy gives a positive result, after a few days the treatment is supplemented with indirect drugs.

In addition, combinations of these drugs are prescribed to patients to prepare for blood transfusion, for operations on the vessels and the heart, and also to prevent thrombosis. True, specialists must constantly monitor the patient's condition, in particular, check the rate of blood clotting, the presence of sediment in the urine, and the level of prothrombin.

Disadvantages of anticoagulant therapy

The key disadvantage of this therapy is that it increases the risk of bleeding. Moreover, bleeding can develop not only on the skin (where they can be noticed in a timely manner), but also in the gastrointestinal tract or in the brain (which endangers the patient's life). Particularly at risk are patients who take high doses of anticoagulants or concomitantly take drugs that increase the effect of anticoagulants.

In this regard, patients who are prone to bleeding, suffering from uncontrolled hypertension, or who have reached the age of 75 cannot take anticoagulants due to the high likelihood of bleeding.

Another disadvantage of this group of drugs is their cost. The cheapest means are medicines based on warfarin. However, their use requires regular laboratory tests to assess the effect of the drug on the blood. And funds based on heparin, as a rule, are used only in a hospital setting.

Finally, the specific side effects of some anticoagulants can also be attributed to the disadvantages. For example, drugs based on heparin provoke thrombocytopenia, and drugs with warfarin cause skin problems up to tissue necrosis. In addition, any anticoagulant can cause a severe allergic reaction or even anaphylactic shock in susceptible patients.

Anticoagulant contraindications

It is worth saying that for some diseases, treatment with blood-thinning drugs is categorically contraindicated. These include:

• erosive and ulcerative lesions of the gastrointestinal tract, which are accompanied by a risk of bleeding;
• severe renal dysfunction, including the development of renal failure;
• the appearance of C or K-vitamin deficiency;
• chronic hepatitis, cirrhosis of the liver, as well as other serious diseases that are accompanied by a violation of the biliary function;
• blood diseases;
• septic endocarditis;
• detection of blood impurities in the cerebrospinal fluid;
• pregnancy (this contraindication is due to the risk of postpartum hemorrhage).

Preparations from the group of indirect anticoagulants are not used during the period of bearing a child, also because they can provoke a violation of the embryonic development of the fetus. Such treatment is also not suitable for people with brain injuries, in view of the possible development of lethargy.

How to determine the effectiveness of anticoagulant therapy?

As we have already noticed, direct anticoagulants are superior to indirect anticoagulants in many respects. However, there is a feature that puts drugs of indirect action in priority. The fact is that the effectiveness of their impact on the body is easy to measure. For this, a special indicator called INR has been developed.

In this plan:

• a patient not taking indirect anticoagulants has an INR of less than 1.0;
• in a patient taking Warfarin and its analogues, the INR index fluctuates at the level of 2.0-3.0 (these indicators are a warning about the possible development of bleeding);
• an INR indicator in the range of 1.0–2.0 indicates that the patient is at risk of ischemic stroke;
• in the case of an INR greater than 4.0, the risk of blood non-clotting, and hence the development of hemorrhagic stroke, is the highest.

But the effectiveness of taking direct anticoagulants cannot be assessed, and this becomes a serious problem for doctors who prescribe such drugs. For example, the need to assess the anticoagulant effect arises when patients are admitted in an unconscious state. And if there is no information on taking direct anticoagulants in the medical record of such a patient, it is quite difficult to identify them in the body. The introduction of anticoagulants in this case can easily provoke an overdose.

What to do in case of an overdose

Doctors are concerned that an antidote has not yet been developed that can quickly and effectively normalize the condition of a patient who has experienced an overdose from taking anticoagulants. If bleeding occurs, doctors administer to the patient a prothrombin complex concentrate, fresh frozen plasma, and Phytonadione (one of the forms of vitamin K).
Take care of yourself!

According to statistics, various thromboembolic complications (pulmonary embolism, deep vein thrombosis) occupy one of the leading places in the structure of mortality in Russia. In medicine, anticoagulants are used to treat such conditions - substances that prevent the formation of thin fibrin filaments under the influence of coagulation factors, inhibit the growth of an already formed thrombus and increase the activity of internal fibrinolytic (aimed at resorption of the thrombus) enzymes.

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  Classification of drugs

  Currently, the classification of anticoagulants is based on the points of application of their effects in the body. Allocate drugs:

  • Direct acting (eg, heparin). They act quickly, their effect is associated with a direct effect on the blood coagulation system through the formation of complexes with different coagulation factors and inhibition of the three phases of coagulation.
  • Indirect action (vitamin K antagonists). They act for a long time, but after a latent (“silent”) period, they stop the activation of the enzyme involved in the conversion of vitamin K, thereby stopping the production of vitamin-dependent plasma coagulation factors (II, VII, IX, X).

  

  Direct acting anticoagulants

  Unfractionated heparin (UFH) is a natural substance obtained from the organs of domestic animals. The mechanism of its action is based on the ability to bind to antithrombin and thereby increase its ability to deactivate coagulation factors IIa, IXa, Xa, XIa, XIIa. Thrombin (factor IIa) is especially sensitive to the effects of the heparin-antithrombin complex.

  The action of heparin is carried out exclusively with parenteral administration: after intravenous administration, activity appears immediately, with subcutaneous administration - after 20-60 minutes with a bioavailability of 10-40% (that is, only this percentage of the substance reaches the systemic circulation). Due to the fact that unfractionated heparin binds to plasma proteins, this drug often exhibits unpredictable anticoagulant effects. To create and maintain the required therapeutic concentration of heparin in the blood, its constant intravenous administration or regular subcutaneous injections, taking into account bioavailability, is necessary. To control treatment, the determination of activated partial thromboplastin time (APTT) is required, the indicators of which should remain within 1.5-2.3 control values.

  Low molecular weight heparins (LMWHs) are chemically or enzymatically processed unfractionated heparin. The mechanism of action is similar to UFH, but LMWHs are significantly more active against clotting factor Xa than thrombin. With intravenous administration, the maximum activity appears after 5 minutes, with subcutaneous administration - after 3-4 hours with a bioavailability of more than 90%, therefore, to maintain a stable level of plasma anticoagulant activity, it is not necessary to carry out a constant intravenous infusion, unlike UFH. Dosing of the drug is carried out individually under the control of anti-Xa blood activity.

  Fondaparinux sodium is a drug that selectively deactivates clotting factor Xa. The bioavailability of the substance when administered subcutaneously is 100%, and the activity is maintained for 17-21 hours, therefore, a single subcutaneous injection is sufficient to achieve a therapeutic concentration.

  Bivalirudin is a substance that directly inhibits the activity of thrombin, the only drug of this kind registered in Russia for parenteral administration. Its action is directed not only to thrombin circulating in the blood, but also to thrombin inside the formed thrombus. The drug is administered exclusively intravenously, and the time of its activity is only 25 minutes. The prescribed doses are fixed and do not require monitoring of blood coagulation parameters.

  

  

  New drugs

  New oral anticoagulants (dabigatran, apixaban, rivaroxaban) are aimed at selective inhibition of any coagulation factor.

  Their effectiveness and safety have been proven by large studies, and laboratory control is not required during application.

  Dabigatran etexilate in the body is converted into the active substance dabigatran, acts on thrombin, is excreted by the kidneys by 80% and causes indigestion in 10% of cases. Apixaban and rivaroxaban are initially active drugs that do not require transformation after admission, act on clotting factor Xa. The average oral bioavailability is more than 50%, and taking rivaroxaban on an empty stomach increases it to almost 100%. The drugs do not cause intolerance from the gastrointestinal tract.

  

  Indirect anticoagulants

  Vitamin K antagonists (VKAs) are drugs that block the conversion of vitamin K to the active form required for the formation of prothrombin, coagulation factors VII, IX, and X in the liver. The actions of drugs in this group are associated with the removal of functioning prothrombin from the blood serum. VKA is used orally in tablets, while their bioavailability is more than 90%. Warfarin is the drug of choice because it provides the most stable anticoagulant effect. Difficulties in the selection of dosages of drugs are possible: their precise regulation according to the international normalized ratio (INR) is required, and the effect of the first dose appears only 5 days after use. VKA overdose is treated with vitamin K, an antidote.

  

  Indications, contraindications and side effects

  Indications, contraindications and side effects of direct anticoagulants. presented in the table:

  List of drugs	Indications	Contraindications	Side effects
  Unfractionated heparin	1. Initial treatment of acute coronary syndrome (myocardial infarction, unstable form of angina pectoris). 2. Prevention and therapy of deep vein thrombosis and pulmonary embolism. 3. Prevention and treatment of complications in the presence of artificial heart valves, intravascular manipulations, hemodialysis, cardiopulmonary bypass. 4. Prevention of thrombosis of intravascular catheters	1. Hypersensitivity. 2. Thrombocytopenia less than 100*10 9 /l. 3. Immune form of thrombocytopenia, as a complication of heparin therapy in history. 4. Uncontrolled active bleeding (except associated with DIC). 5. Suspected intracranial bleeding	bleeding; allergic reactions; hyperkalemia; headache, fever, chills; peripheral neuropathy; increase in ALT, AsAT;
  Low molecular weight heparins	Same as unfractionated heparin	Same as unfractionated heparin plus allergy to pork products	bleeding; allergic reactions; osteoporosis; hyperkalemia; nausea, diarrhea; increase in ALT, AsAT; local reactions with subcutaneous injections
  Fondaparinux sodium	1. Early therapy of acute coronary syndrome (myocardial infarction, unstable angina). 2. Prevention and therapy of deep vein thrombosis and pulmonary embolism. 3. Therapy of thrombosis of the saphenous veins of the lower extremities	2. Hemorrhagic diathesis. 4. Active bleeding. 5. Bacterial endocarditis	bleeding; allergic reactions; hypokalemia; stomach ache; increase in ALT, AsAT; local reactions with subcutaneous injections
  Bivalirudin	1. Percutaneous coronary intervention (PCI), including in the complex of primary procedures for acute coronary syndrome with ST segment elevation. 2. Therapy of immune thrombocytopenia as a complication of heparin therapy	1. Allergy or hypersensitivity. 2. Hemorrhagic diathesis. 3. Severe renal failure. 4. Heavy active bleeding. 5. Subacute bacterial endocarditis. 6. Age up to 18 years. 7. Severe arterial hypertension	bleeding; allergic reactions
  New oral anticoagulants (dabigatran, apixaban, rivaroxaban)	1. Prevention of deep vein thrombosis and pulmonary embolism in planned hip and knee arthroplasty. 2. Prevention of strokes and thromboembolism in atrial fibrillation	1. Hypersensitivity. 2. Continued bleeding. 2. Hemorrhagic diathesis. 4. Hemorrhagic stroke in history. 5. Severe renal and hepatic insufficiency. 6. Pregnancy and lactation. 7. Age under 18	bleeding; increase in ALT and AST; hyperbilirubinemia; dyspepsia (for dabigatran etexilate)

  Indications for the appointment of vitamin K antagonists are:

  • prevention and treatment of venous thrombosis and pulmonary embolism;
  • therapy of thromboembolic events in high-risk patients (in the presence of artificial valves, atrial fibrillation);
  • prevention of coronary complications in coronary heart disease;
  • prevention of thrombotic events in antiphospholipid syndrome (elevated lupus anticoagulant).

  

  Contraindications for Warfarin:

  Type of anticoagulantTrade name example (manufacturer) ApixabanDirect factor Xa inhibitorEliquis (Bristol-Myers Squibb Company; Pfizer) AcenocoumarolVitamin K antagonistSinkumar (ICN Polfa Rzeszow) BivalirudinDirect thrombin inhibitorAngioks (Ben Venue Laboratories Inc.) warfarinVitamin K antagonistWarfarex (Grindeks JSC) Heparin sodiumdirect actionTrombless (NIZHFARM OJSC), Lyoton (A. Menarini Industrie Farmaceutiche Riunite S.r. L.), Heparin (Synthesis OJSC) Dabigatran etexilateDirect thrombin inhibitorEliquis (Bristol-Myers Squibb Company), Pradaxa (Boehringer Ingelheim Pharma) RivaroxabanDirect factor Xa inhibitorXarelto (Bayer Pharma AG) phenindioneVitamin K antagonistFenilin (Tallinn Pharmaceutical Plant) Fondaparinux sodiumDirect factor Xa inhibitorArixtra (Glaxo Wellcome Production) Enoxaparin sodiumDirect acting, low molecular weight heparinClexane (Sanofi-Winthrop Industrie)

Anticoagulants are a group of drugs that inhibit blood clotting and prevent thrombosis by reducing the formation of fibrin.

Anticoagulants affect the biosynthesis of certain substances that inhibit clotting processes and change blood viscosity.

In medicine, modern anticoagulants are used for preventive and therapeutic purposes. They are available in different forms: in the form of ointments, tablets or solutions for injection.

Only a specialist can choose the right drugs and choose their dosage.

Improperly performed therapy can harm the body and cause serious consequences.

High mortality due to cardiovascular diseases is explained by the formation of blood clots: almost half of those who died from heart disease were found to have thrombosis.

Venous thrombosis and PE are the most common causes of disability and death. Therefore, cardiologists recommend starting to use anticoagulants immediately after the discovery of vascular and heart diseases.

Their early use helps prevent the formation and increase of a blood clot, clogging of blood vessels.

Most anticoagulants do not act on the blood clot itself, but on the blood coagulation system.

After a series of transformations, plasma coagulation factors are suppressed and the production of thrombin, an enzyme required to create fibrin filaments that form a thrombotic clot, occurs. As a result, thrombus formation slows down.

The use of anticoagulants

Anticoagulants are indicated for:

Contraindications and side effects of anticoagulants

Anticoagulants are contraindicated in people suffering from the following diseases:

• Bleeding hemorrhoids;
• Peptic ulcer of the duodenum and stomach;
• Renal and liver failure;
• Liver fibrosis and chronic hepatitis;
• thrombocytopenic purpura;
• Urolithiasis disease;
• Deficiency of vitamins C and K;
• Cavernous pulmonary tuberculosis;
• Pericarditis and endocarditis;
• Malignant neoplasms;
• Hemorrhagic pancreatitis;
• Intracerebral aneurysm;
• Myocardial infarction with hypertension;
• Leukemia;
• Crohn's disease;
• Alcoholism;
• Hemorrhagic retinopathy.

Anticoagulants should not be taken during menstruation, pregnancy, lactation, in the early postpartum period, the elderly.

Side effects include: symptoms of intoxication and dyspepsia, necrosis, allergies, rash, skin itching, osteoporosis, kidney dysfunction, alopecia.

Complications of therapy - bleeding from internal organs:

• Nasopharynx;
• Intestines;
• Stomach
• Hemorrhages in the joints and muscles;
• The appearance of blood in the urine.

To prevent the development of dangerous consequences, it is necessary to monitor the patient's condition and monitor blood counts.

Natural anticoagulants

They can be pathological and physiological. Pathological in some diseases appear in the blood. Physiological are normally found in plasma.

Physiological anticoagulants are divided into primary and secondary. The first are independently synthesized by the body and are constantly present in the blood. Secondary appear during the splitting of coagulation factors in the process of formation and dissolution of fibrin.

Primary natural anticoagulants

Classification:

• Antithrombins;
• Antithromboplastins;
• Fibrin self-assembly inhibitors.

With a decrease in the level of primary physiological anticoagulants in the blood, there is a risk of thrombosis.

This group of substances includes the following list:

Secondary physiological anticoagulants

Formed during blood clotting. They also appear during the breakdown of coagulation factors and the dissolution of fibrin clots.

Secondary anticoagulants - what is it:

• Antithrombin I, IX;
• fibrinopeptides;
• Antithromboplastins;
• PDF products;
• Metafactors Va, XIa.

Pathological anticoagulants

With the development of a number of diseases, strong immune coagulation inhibitors can accumulate in plasma, which are specific antibodies, like lupus anticoagulant.

These antibodies indicate a specific factor, they can be produced to combat the manifestations of blood clotting, but according to statistics, these are inhibitors of factor VII, IX.

Sometimes, with a number of autoimmune processes in the blood and paraproteinemias, pathological proteins with antithrombin or inhibitory effects can accumulate.

The mechanism of action of anticoagulants

These are drugs that affect blood clotting, are used to reduce the risk of blood clots.

Due to the formation of a blockage in organs or vessels, the following may develop:

• Gangrene of the limbs;
• Ischemic stroke;
• thrombophlebitis;
• ischemia of the heart;
• Inflammation of blood vessels;
• Atherosclerosis.

According to the mechanism of action, anticoagulants are divided into drugs of direct / indirect action:

"Direct"

Act directly on thrombin, lowering its activity. These drugs are prothrombin deactivators, thrombin inhibitors and inhibit thrombus formation. In order to prevent internal bleeding, it is necessary to control the parameters of the coagulation system.

Direct anticoagulants quickly enter the body, are absorbed in the gastrointestinal tract and reach the liver, have a therapeutic effect and are excreted in the urine.

They are divided into the following groups:

• Heparins;
• Low molecular weight heparin;
• Hirudin;
• sodium hydrocitrate;
• Lepirudin, danaparoid.

Heparin

The most common anti-clotting agent is Heparin. It is a direct acting anticoagulant drug.

It is administered intravenously, intramuscularly and under the skin, and is also used as an ointment as a topical remedy.

Heparins include:

• Adreparin;
• Nadroparin sodium;
• Parnaparin;
• Dalteparin;
• Tinzaparin;
• Enoxaparin;
• Reviparin.

Antithrombotic drugs of local action have not very high efficiency and insignificant permeability in the tissue. Used to treat hemorrhoids, varicose veins, bruises.

The most commonly used with heparin are the following:

Heparins for subcutaneous and intravenous administration are drugs that reduce clotting, which are individually selected and are not replaced by one another during treatment, since they are not equivalent in effect.

The activity of these drugs reaches a maximum after about 3 hours, and the duration of action is a day. These heparins block thrombin, reduce the activity of plasma and tissue factors, prevent the formation of fibrin filaments, and prevent platelet aggregation.

For the treatment of angina, heart attack, pulmonary embolism and deep vein thrombosis, Deltaparin, Enoxaparin, Nadroparin are usually prescribed.

For the prevention of thrombosis and thromboembolism, Reviparin and Heparin are prescribed.

sodium hydrocitrate

This anticoagulant is used in laboratory practice. It is added to test tubes to prevent blood clotting. It is used to preserve blood and its components.

"Indirect"

They affect the biosynthesis of side enzymes of the coagulation system. They do not suppress the activity of thrombin, but completely destroy it.

In addition to anticoagulant effects, drugs of this group have a relaxing effect on smooth muscles, stimulate blood supply to the myocardium, remove urates from the body and have a hypocholesterolemic effect.

"Indirect" anticoagulants are prescribed for the treatment and prevention of thrombosis. They are used exclusively inside. The form of tablets is used for a long time in an outpatient setting. Abrupt withdrawal leads to an increase in prothrombin and thrombosis.

These include:

"Indirect" drugs include:

• neodicumarin;
• Warfarin;
• Acenocoumarol.

Warfarin (thrombin inhibitors) should not be taken for certain diseases of the liver and kidneys, thrombocytopenia, with a tendency to bleeding and acute bleeding, during pregnancy, with DIC, congenital deficiency of proteins S and C, lactase deficiency, if the absorption of glucose and galactose is impaired.

Side effects include nausea, vomiting, abdominal pain, diarrhea, bleeding, nephritis, alopecia, urolithiasis, allergies. There may be itching, skin rash, vasculitis, eczema.

The main disadvantage of Warfarin is an increased risk of bleeding (nasal, gastrointestinal, and others).

New generation oral anticoagulants (NOACs)

Anticoagulants are indispensable drugs used in the treatment of many pathologies, such as thrombosis, arrhythmias, heart attacks, ischemia, and others.

However, drugs that have proven effective have many side effects.. Development continues, and new anticoagulants occasionally appear on the market.

Scientists are trying to develop universal remedies that are effective in various diseases. Drugs are being developed for children and patients for whom they are contraindicated.

New generation blood thinners have the following advantages:

• The action of the drug comes on and off quickly;
• When taken, the risk of bleeding is reduced;
• The drugs are indicated for patients who cannot take Warfarin;
• The inhibition of thrombin-related factor and thrombin is reversible;
• The influence of food consumed, as well as other drugs, is reduced.

However, the new drugs also have disadvantages:

• Must be taken regularly, while older remedies can be skipped due to long-term effect;
• Lots of tests
• Intolerance by some patients who could take old pills without side effects;
• Risk of bleeding in the gastrointestinal tract.

The list of new generation drugs is small.

The new drugs Rivaroxaban, Apixaban and Dabigatran may be alternatives for atrial fibrillation. Their advantage is the absence of the need to constantly donate blood during the reception, they do not interact with other drugs.

However, NOACs are just as effective if the risk of bleeding is not higher.

Antiplatelet agents

They also help thin the blood, but they have a different mechanism of action: antiplatelet agents prevent platelets from sticking together. They are prescribed to enhance the effect of anticoagulants. In addition, they have a vasodilating and antispasmodic effect.

The most famous antiplatelet agents:

• Aspirin is the most commonly used antiplatelet agent. An effective agent that thins the blood, dilates blood vessels and prevents thrombosis;
• Tirofiban - interferes with the adhesion of platelets;
• Eptifibatite - inhibits platelet aggregation;
• Dipyridamole is a vasodilator;
• Ticlopidin - used for heart attacks, cardiac ischemia and in the prevention of thrombosis.

The new generation includes Brilint with the substance ticagrelor. It is a reversible P2U receptor antagonist.

Conclusion

Anticoagulants are indispensable drugs in the treatment of pathologies of the heart and blood vessels. They cannot be taken on their own.

Anticoagulants have many side effects and contraindications, and uncontrolled intake can cause bleeding, including hidden ones. The appointment and calculation of the dosage are performed by the attending physician, who can take into account all the possible risks and features of the course of the disease.

During treatment, regular laboratory monitoring is required.

It is very important not to confuse anticoagulants and antiplatelet agents with thrombolytic agents. The difference lies in the fact that anticoagulants do not destroy the thrombus, but only slow down or prevent its development.

Drugs that can slow down the work of the human blood clotting system are called anticoagulants.

Their action is due to the inhibition of the metabolism of those substances that are responsible for the production of thrombin and other components capable of forming a blood clot in the vessel.

They are used for many diseases, during which the risk of thrombus formation in the venous system of the lower extremities, the vascular system of the heart and lungs increases.

Discovery history

The history of anticoagulants began at the beginning of the twentieth century. In the fifties of the last century, the world of medicine has already received a medicine that can thin the blood, with the active ingredient coumarin.

The first patented anticoagulant was (WARFARIN) and it was intended exclusively for baiting rats, since the drug was considered extremely toxic to humans.

However, the increasing rate of unsuccessful suicide attempts with warfarin has forced scientists to change their minds about its danger to humans.

So in 1955, Warfarin began to be prescribed to patients who had suffered a myocardial infarction. To this day, Warfarin ranks 11th among the most popular anticoagulants of our time.

Direct and indirect anticoagulants

NLA indirect action

New anticoagulants of indirect action in one way or another affect the metabolism of vitamin K.

All anticoagulants of this type are divided into two groups: monocoumarins and dicoumarins.

At one time, such drugs as Warfarin, Sincumar, Dicoumarin, Neodicumarin and others were developed and released.

Since then, radically new substances that affect the level of vitamin K have not been developed.

Taking such drugs has a large number of contraindications and additional, often inconvenient, tests and dietary compliance.

Someone who is taking indirect anticoagulants should:

• calculate the daily intake of vitamin K;
• regularly monitor INR;
• be able to change the level of hypocoagulation in intercurrent diseases;
• monitor the possible sharp appearance of symptoms of internal bleeding, in which you immediately contact a doctor and switch to another group of anticoagulants in the near future.

But anticoagulants are not strictly divided into drugs of direct and indirect action. There are several groups of substances that have the ability to thin, in one way or another, the blood. For example, enzyme anticoagulants, inhibitors of platelet aggregation, and others.

So the market has a new Brilinta antiplatelet agent. The active substance is ticagrelor. A member of the cyclopentyltriazolopyrimidine class, it is a reversible P2U receptor antagonist.

direct action PLA

New anticoagulants of indirect action include the following drugs.

Dabigatran

New anticoagulant direct inhibitor of thrombin. Dabigatran etexilate is the low molecular weight precursor of the active form of dabigatran. The substance inhibits free thrombin, fibrin-binding thrombin and platelet aggregation.

Most often applied for the prevention of venous thromboembolism especially after joint replacement.

In pharmacies, you can find a medicine with the active ingredient dabigatran - Pradaxa. Available in the form of capsules, with a content of dabigatran etexilate 150 mg per capsule.

Rivaroxaban

Highly selective factor Xa inhibitor. Rivaroxaban is able to dose-dependently increase the APTT and the HepTest result. The bioavailability of the drug is about 100%. Does not require monitoring of blood parameters. The variation coefficient of individual variability is 30-40%.

One of the brightest representatives of the drug containing rivaroxaban is Xarelto. Available in tablets of 10 mg of the active substance each.

Apixaban

The drug can be prescribed to patients who are contraindicated in taking vitamin K antagonists.

Compared with acetylsalicylic acid, it has a low probability of embolism. Apixaban selectively inhibits the clotting factor FXa. It is mainly prescribed after a planned arthroplasty of the knee or hip joint.

Produced under the name Eliquis. It has an oral form.

Edoxaban

The drug belongs to the newest class of fast-acting factor Xa inhibitors. As a result of clinical studies, it was found that Edoxaban has the same ability to prevent the formation of blood clots with Warfarin.

And at the same time, it has a significantly lower likelihood of bleeding.

Features of taking these drugs

Should use with caution in elderly patients, with a significant deviation of weight from the norm, with a violation of the function of the kidneys, diseases associated with an abnormal function of the circulatory system.

One feature of many of the newer anticoagulants is their rapid response and rapid half-life. This suggests that it is necessary to be extremely careful in observing the regimen of taking pills. Since even skipping one pill can lead to complications.

For bleeding that occurs as a result of therapy with certain anticoagulants, there is a specific treatment.

For example, when bleeding due to Rivaroxaban, the patient is given prothrombin concentrate or fresh frozen plasma. With blood loss due to Dabigatran, hemodialysis, recombinant FVIIa, is performed.

findings

The development of new anticoagulants is still ongoing. Problems with side effects in the form of bleeding are still not solved.

Even some new drugs require control.

The number of contraindications, although reduced, has not been completely eliminated. Some drugs still have slightly increased toxicity.

Therefore, scientists continue to search for a universal remedy with high bioavailability, lack of tolerance, absolute safety and intelligent regulation of the level of prothrombin in the blood, depending on other factors that affect it.

An important aspect is the presence of an antidote in the drug, if necessary, an immediate operation.

Nevertheless, new drugs, in comparison with drugs of the last century, have very noticeable positive differences, which indicates the titanic work of scientists.

Various vascular diseases lead to the formation of blood clots. This leads to very dangerous consequences, as, for example, a heart attack or stroke can occur. To thin the blood, the doctor may prescribe drugs that help reduce blood clotting. They are called anticoagulants and are used to prevent blood clots from forming in the body. They help block the formation of fibrin. Most often they are used in situations where blood clotting is increased in the body.

It can occur due to problems such as:

• Varicose veins or phlebitis;
• thrombi of the inferior vena cava;
• Thrombi in hemorrhoidal veins;
• Stroke;
• myocardial infarction;
• Arterial injury in the presence of atherosclerosis;
• Thromboembolism;
• Shock, trauma, or sepsis can also lead to blood clots.

To improve the state of blood clotting, anticoagulants are used. If earlier they used Aspirin, now doctors have abandoned this technique, because there are much more effective drugs.

What are anticoagulants, farm. Effect

Anticoagulants- these are blood thinning drugs, in addition, they reduce the risk of other thrombosis that may appear in the future. Distinguish anticoagulants of direct and indirect action.

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Direct and indirect anticoagulants

There are direct and indirect anticoagulants. The former quickly thin the blood and are excreted from the body within a few hours. The latter accumulate gradually, providing a therapeutic effect in a prolonged form.

Since these drugs reduce blood clotting, you can not lower or increase the dosage on your own, as well as reduce the time of admission. Medicines are used according to the scheme prescribed by the doctor.

Direct acting anticoagulants

Direct acting anticoagulants reduce thrombin synthesis. In addition, they inhibit the formation of fibrin. Anticoagulants are aimed at the work of the liver and inhibit the formation of blood clotting.

Direct anticoagulants are well known to everyone. These are local heparins and for subcutaneous or intravenous administration. In another article you will find even more information about.

For example, local action:

These drugs are used for thrombosis of the veins of the lower extremities for the treatment and prevention of the disease.

They have a higher degree of penetration, but have less effect than intravenous agents.

Heparins for administration:

• Fraxiparine;
• Clexane;
• Fragmin;
• Clivarin.

Typically, anticoagulants are selected to solve specific problems. For example, Klivarin and Troparin are used to prevent embolism and thrombosis. Clexane and Fragmin - for angina pectoris, heart attack, vein thrombosis and other problems.

Fragmin is used in hemodialysis. Anticoagulants are used at the risk of blood clots in any vessels, both in the arteries and in the veins. The activity of the drug persists for a whole day.

Indirect anticoagulants

Indirect anticoagulants are so named because they affect the creation of prothrombin in the liver, and do not directly affect clotting itself. This process is long, but the effect due to this is prolonged.

They are divided into 3 groups:

• Monocoumarins. These include: Warfarin, Sinkumar, Mrakumar;
• Dicoumarins are Dicoumarin and Tromexane;
• Indandiones are Phenylin, Omefin, Dipaksin.

Most often, doctors prescribe warfarin. These drugs are prescribed in two cases: with atrial fibrillation and artificial heart valves.

Often patients ask what is the difference between Aspirin cardio and Warfarin, and is it possible to replace one drug with another?

Experts answer that Aspirin cardio is prescribed if the risk of stroke is not high.

Warfarin is much more effective than Aspirin and is best taken for several months, if not for life.

Aspirin corrodes the stomach lining and is more toxic to the liver.

Indirect anticoagulants reduce the production of substances that affect clotting, they also reduce the production of prothrombin in the liver and are vitamin K antagonists.

Indirect anticoagulants include vitamin K antagonists:

• Sincumar;
• Warfarex;
• Fenilin.

Vitamin K is involved in the process of blood clotting, and under the influence of Warfarin, its functions are impaired. It helps to prevent the separation of blood clots and blockage of blood vessels. This drug is often prescribed after a myocardial infarction.

It is necessary to carefully consider taking this drug, as it has a lot of contraindications to food products that should not be consumed simultaneously with these drugs.

There are direct and selective thrombin inhibitors:

Direct:

• Angioks and Pradaksa;

Selective:

• Eliquis and.

Any anticoagulants of direct and indirect action are prescribed only by a doctor, otherwise there is a high risk of bleeding. Anticoagulants of indirect action accumulate in the body gradually.

Apply them only inside orally. It is impossible to stop treatment immediately, it is necessary to gradually reduce the dose of the drug. Abrupt withdrawal of the drug can cause thrombosis. An overdose of this group may cause bleeding.

The use of anticoagulants

The clinical use of anticoagulants is recommended for the following conditions:

• Pulmonary and myocardial infarction;
• Stroke embolic and thrombotic (except hemorrhagic);
• Phlebothrombosis and thrombophlebitis;
• Embolism of vessels of various internal organs.

As a preventive measure, you can use it for:

• Atherosclerosis of the coronary arteries, cerebral vessels and peripheral arteries;
• Heart defects rheumatic mitral;
• Phlebothrombosis;
• Postoperative period to prevent the formation of blood clots.

Natural anticoagulants

Thanks to the process of blood clotting, the body itself made sure that the clot does not go beyond the affected vessel. One milliliter of blood can help clotting all the fibrinogen in the body.

Due to its movement, the blood maintains a liquid state, as well as due to natural coagulants. Natural coagulants are produced in the tissues and then enter the bloodstream, where they prevent the activation of blood clotting.

These anticoagulants include:

• Heparin;
• Antithrombin III;
• Alpha-2 macroglobulin.

Anticoagulant drugs - list

Direct-acting anticoagulants are absorbed quickly and their duration of action is not more than a day before re-introduction or application.

Anticoagulants
indirect action accumulate in the blood, creating a cumulative effect.

They should not be canceled immediately, as this may contribute to thrombosis. When taking them, gradually reduce the dosage.

Direct local anticoagulants:

• Lyoton gel;
• Hepatrombin;
• Trombless

Anticoagulants for intravenous or intradermal administration:

• Fraxiparine;
• Clexane;
• Fragmin;
• Clivarin.

Indirect anticoagulants:

• Girugen;
• Girulog;
• Argatroban;
• Warfarin Nycomed in tab.;
• Fenilin in tab.

Contraindications

There are quite a few contraindications to the use of anticoagulants, so be sure to check with your doctor about the appropriateness of taking the funds.

Cannot be used when:

• peptic ulcer;
• Parenchymal diseases of the liver and kidneys;
• Septic endocarditis;
• Increased vascular permeability;
• With increased pressure in myocardial infarction;
• oncological diseases;
• Leukemia;
• Acute aneurysm of the heart;
• Allergic diseases;
• Diathesis hemorrhagic;
• Fibromyomas;
• Pregnancy.

With caution during menstruation in women. Not recommended for nursing mothers.

Side effects

With an overdose of drugs of indirect action, bleeding may begin.

At
co-administration of Warfarin with aspirin or other non-steroidal anti-inflammatory drugs (Simvastin, Heparin, etc.) enhances the anticoagulant effect.

And vitamin K, laxatives or Paracetamol will weaken the effect of Warfarin.

Side effects when taking:

• Allergy;
• temperature, headache;
• Weakness;
• skin necrosis;
• Violation of the kidneys;
• Nausea, diarrhea, vomiting;
• Itching, abdominal pain;
• Baldness.

Before you start taking anticoagulants, you should consult a specialist for contraindications and side effects.