HealthPreparations

Anticoagulants of direct and indirect action. Indirect anticoagulants: list of drugs, mechanism of action, classification. Overdose with indirect anticoagulants

With the proper functioning of coagulated and anti-convoluted blood systems, the internal balance of the organism is normalized. The blood flow through the vessels does not have obstacles and limitations, and thrombus formation is at the correct level. When the balance of the functioning of the systems is violated in favor of activating the clotting of blood, conditions appear that can lead to excessive clot formation. Indirect anticoagulants - one of the groups of drugs used to restore internal disorders.

What is anticoagulants?

Anticoagulants are agents that have an anticoagulable effect and activate blood thinning. This allows you to restore the rheological features and reduce the level of development of thrombosis.

The drugs are available in tablet form, in the form of ointments, gels and injections. They are prescribed not only for the treatment of diseases, but also for the purpose of preventing the increased formation of blood clots.

Most of the representatives of this group of drugs do not act on the formed blood clot, but on the activity of the clotting system. There is a process of affecting plasma factors and thrombin production, which slows down thrombus formation.

The drugs are divided into two groups depending on their action:

  • Direct anticoagulants;
  • Indirect anticoagulants.

Direct action drugs based on heparin

This group of agents has a direct effect on plasma cofactors inhibiting thrombin. The main representative is heparin. On its basis, there are a number of medications that act similarly and have a consonant name:

  • "Ardeparin."
  • "Nadroparin".
  • "Cleaver".
  • Longyparin.
  • "Sandoparin".

Heparin or derivatives combine with antithrombin-III, which leads to a change in the arrangement of its molecules. This speeds up the cofactor's attachment to thrombin, and then to the inactivation of the clotting process.

Features of the application of "Heparin"

The action of the substance is aimed at preventing the growth and spread of the blood clot. Molecules of heparin form a complex with antithrombin, which is an inhibitor of coagulation factors. The substance is a chain of glycosaminoglycans. The drug is administered subcutaneously and begins to work in a couple of hours.

If you need a quick action, "Heparin" is injected intravenously to accelerate the effectiveness and increase bioavailability. The choice of dosage depends on the condition in which the patient is. In addition, the presence of concomitant diseases, the parallel reception of other groups of medications, the need for surgical interventions on the vessels are taken into account.

Oligopeptides

Medications directly acting on the center of thrombin activation are considered to be strong specific inhibitors of the thrombogenesis system. The active substances of the preparations are themselves connected to the coagulation factors, changing their conformation.

These drugs are "Inogatran", "Hirudin", "Efegatran", "Tromstop" and others. Used to prevent the development of heart attacks in angina pectoris, with varicose veins, for the prevention of thromboembolism, reocclusion during vascular plastic surgery.

Indirect anticoagulants (list)

The first anticoagulant was obtained in the XX century in the US, when a new disease of cows was discovered provoking profuse bleeding. When the cause of the pathological condition was clarified, it turned out that the animal's organism is affected by a mold that is infected with mold, which is in the stern. From this raw material, the first preparation of antiaggregant indirect action, "Dicumarol", was synthesized.

To date, the list of funds that are analogs, is more than a hundred titles. All these drugs are indirect anticoagulants. The mechanism of action of a group of medicines is based on the inhibition of the action of vitamin K.

There are clotting factors that depend on this vitamin. Indirect anticoagulants inhibit activation of clotting proteins and vitamin-dependent cofactors. Uncontrolled use of such drugs is prohibited, as the risk of hemorrhagic complications increases.

There are two main groups to which all indirect anticoagulants are divided. Classification of funds is based on the active substance, which is part of the drugs. Distinguish:

  • Coumarin derivatives;
  • Means based on indandion.

Preparations of indandion

After carrying out a large number of studies, scientists found that the funds based on this active substance should not be used in therapy. The drugs had a significant number of side effects in the form of allergic reactions. The effectiveness of the anti-coagulation system also did not show stable results.

This group of medicines includes preparations: "Fenindion", "Diphenindion", "Anisindion." It was decided to stop the main choice on the second group of antiplatelet agents, and only the "Fenilin" is used from indandione derivatives at the moment.

The drug has a low cost, is available in tablet form. It lasts for 10 hours, and it is very important to maintain the necessary duration of therapy. The effect occurs only 24 hours after the first reception. The use of funds occurs under the monitoring of the patient's condition with the help of laboratory blood indicators (coagulogram, general analyzes, biochemistry).

Scheme of application of "Phenylin":

  1. The first day - 1 tablet 4 times.
  2. The second day - 1 tablet 3 times.
  3. The rest of the therapy is 1 tablet a day.

It is not recommended to take the drug simultaneously with drugs that reduce the level of glucose in the body.

Coumarin derivatives

Kumarin is a substance that is found in plants and can be produced synthetically under laboratory conditions. First, after it was removed, the remedy was used as a poison for fighting rodents. Only after the passage of time the drug was used to combat excessive thrombosis.

Anticoagulants of indirect action - preparations based on coumarin - are represented by the following medicamental agents:

  • "Warfarin" (its counterparts are "Marevan", "Warfarin sodium", "Warfarex").
  • "Azenokumarol" (analog - "Sinkumar").
  • "Neodikumarin" (analog - "Ethylbiskumacetate").

Warfarin: application features

Anticoagulants of indirect action (the list is available in the article) are most often represented by "Warfarin". This is a tablet product, available at 2.5, 3 or 5 mg. The effect on the human body develops after 1.5-3 days from the first tablet. The maximum effect develops by the end of the first week.

After the end of taking the drug rheological blood counts return to their normal state after 5 days from the date of cancellation of Warfarin. The drug is applied 2 times a day at the same time. On the 5th day from the beginning of therapy, the blood counts are checked to determine the appropriateness and effectiveness of the application.

The course of treatment is selected by a specialist in each case individually. Some pathological conditions (eg, atrial fibrillation) require continuous application. With the development of PE (pulmonary embolism), an antiaggregant is prescribed for at least six months or for life.

If it is necessary to carry out an operation, Warfarin should be canceled 5 days before the operation. This will allow blood indicators to return to normal. If there is a high need for continued use of anticoagulant therapy, this remedy is replaced by nonfractional heparin. The last dose is administered 4 hours before the intervention.

After the operation, after 4 hours, nephraktic heparin is re-introduced. Reception of indirect antiplatelet agents can be returned in two days, after monitoring the blood state with the help of laboratory tests.

In what cases are anticoagulants prescribed?

Direct and indirect anticoagulants are used to prevent the development of thromboembolism, acute thrombosis of the venous system, in the case of mechanical prosthesis of the heart valves and the development of atrial fibrillation.

The main diseases, in the development of which anticoagulants of direct and indirect action are prescribed, have the following division into groups:

  1. Thrombosis of the arterial system:
    • Myocardial infarction;
    • pulmonary embolism;
    • Stroke with manifestations of ischemia;
    • Traumatic lesions of arteries against the background of atherosclerosis.
  2. Disseminated intravascular coagulation :
    • Shock states;
    • Traumatic injuries;
    • Development of sepsis.
  3. Acute thrombosis from the veins:
    • A thrombus formation on a background of varices;
    • Thrombosis of hemorrhoidal venous plexuses;
    • Formation of clots in the inferior vena cava.

Basic Contraindications

Indirect anticoagulants are drugs that are strictly prohibited in the presence of lactose deficiency, impaired absorption of glucose or galactose. There are a number of drugs that can not be used simultaneously with indirect anticoagulants. The list of preparations consists of non-steroidal anti-inflammatory drugs: "Aspirin", "Dipiridamol", "Clopidogrel", "Penicillin", "Chloramphenicol", "Cimetidine".

Conditions in which anticoagulants of direct and indirect action can not be used:

  • Ulcerative diseases of the gastrointestinal tract;
  • Aneurysms of blood vessels;
  • Liver disease;
  • Acute bleeding;
  • Thrombocytopenia;
  • Kidney failure;
  • I trimester and last month of pregnancy;
  • High level of creatinine.

Adverse effects of antiplatelet agents

Each of the drugs in this group of drugs has similar side effects. They are manifested by self-medication, incorrectly chosen dose or violation of recommendations for use.

Side effects include the development of bleeding, dyspeptic manifestations in the form of vomiting, nausea and diarrhea. There is a strong pain in the abdomen, allergic skin rashes like hives or eczema. It can develop necrosis, hair loss, itching of the skin.

Before starting therapy, the patient must pass a series of tests to determine the possibility of using such drugs. The patient gives a general blood test, biochemistry, general urine analysis, urine by Nechiporenko, coagulogram. It is also recommended to perform an ultrasound examination of the kidneys and hand over the feces to the latent blood.

Overdose with indirect anticoagulants

Cases of overdose of this group of drugs are quite rare. This can happen if a small child finds a drug at home and tries it on the palate. Usually the concentration of the substance is low, so a single pill is not terrible. In the case of special or unintentional use of large doses of substance, coagulopathy and bleeding may develop.

The overdose clinic has no specific symptoms, so it's difficult to guess that a large amount of the drug has been taken. Symptomatic manifestations are similar to various diseases and pathological conditions of the body. The patient appears:

  • Light bruises on the skin;
  • The appearance of blood in the urine or feces;
  • Uterine bleeding;
  • Hematomas in the neck;
  • Intracranial hemorrhage.

Previous stroke, elderly age, gastrointestinal hemorrhage in history and low hematocrit are concomitant factors that can reduce the susceptibility threshold of the concentration of medications.

Therapy of antiaggregant overdose

  1. Purify or wash the stomach a few hours after taking the medication does not make any sense.
  2. The patient is given activated charcoal for intestinal absorption.
  3. In case of an overdose of "Warfarin" or its analogs, "Cholestyramine" is prescribed internally.
  4. The patient is placed in anti-traumatic conditions to avoid the appearance of new hematomas and hemorrhages.
  5. With significant blood loss, a blood or plasma transfusion is performed, sometimes whole blood. Erythrocytic mass, cryoprecipitate, prothrombin complex are effective in use.
  6. "Phytomenadion", preparations based on vitamin K.
  7. If there is no need to prescribe antiplatelet therapy, then the preparation "Phytomenadion" is prescribed by the course of treatment, and not as a first aid.

If the patient's condition is normal, but he needs to continue to use indirect anticoagulants, then "Warfarin" should be temporarily replaced with drugs of the heparin series.

Conclusion

The use of antiaggregant drugs allows not only to normalize rheological blood standards, but also to improve the general condition of the patient and prevent the possibility of developing serious diseases.

Attentive to the use of anticoagulants, the choice of dosage and monitoring the patient's condition will help reduce the risk of complications and succeed. Specialists who use this group of drugs in their practice need to improve their knowledge and strictly observe international medical recommendations.

Similar articles

 

 

 

 

Trending Now

 

 

 

 

Newest

Copyright © 2018 en.birmiss.com. Theme powered by WordPress.