One of the most successful methods farmakoprofilaktiki formation of blood clots in the blood vessels is the use of special drugs, antiplatelet agents.The mechanism of blood clotting is a complex physiological and biochemical processes and briefly described on our website in the article "The anticoagulants of direct action."One of the stages of blood coagulation is aggregation (bonding) of platelets to each other to form a primary thrombus.Antiplatelet drugs exert their effects at this stage.By acting on the biosynthesis of certain substances they oppress (inhibit) platelet adhesion process, the primary blood clot does not form, and the stage of enzymatic coagulation does not occur.
mechanisms of the antiplatelet effect, particularly the pharmacokinetics and pharmacodynamics of different drugs at different, so will be described below. Content
As a rule, drugs group antiplatelet agents are used in the following clinical situations:
General contraindications to the use of drugs of this group are:
have separate representatives of antiplatelet agents are different from other drugs of this group of indications and contraindications.
The group of antiplatelet agents include drugs:
consider each of them in detail.
This substance though a nonsteroidal anti-inflammatory drugs, but also affects blood clotting.Thus, inhibiting the biosynthesis of thromboxane A2 in platelets, it violates their aggregation processes: the process slows down clotting.Applied in large doses, acetylsalicylic acid attacks and other coagulation factors (inhibits the biosynthesis of prostaglandins antithrombotic as well as the release and activation of platelet factor III and IV), which causes the development of a more pronounced antiplatelet effect.
most commonly used for the prevention of thrombosis.
If ingestion is well absorbed in the stomach.As we move through the intestines and increase the absorption of its pH is gradually reduced.Suck the blood is transported to the liver where it changes the chemical structure under the influence of biologically active substances of the organism.It penetrates the blood-brain barrier in the breast milk and cerebrospinal fluid.Excreted from the body mainly by the kidneys.
effect of acetylsalicylic acid develops within 20-30 minutes after a single ingestion.The half-life depends on the age of the patient and the dose of the drug varies in the range of 2-20 hours.
release form - pill.
Recommended dose as antiplatelet agents - 75-100-325 mg depending on the clinical situation.It has ulcerative effect (able to trigger the development of stomach ulcers), so be sure to take the medication after meals, drinking plenty of fluids: water, milk, or an alkaline mineral water.
Contraindications to the use of acetylsalicylic acid described in the general part of the article, you only add to them, and even asthma (some people aspirin can trigger an attack of bronchospasm, the so-called aspirin asthma).
The treatment with this drug may develop adverse effects, such as:
This drug for antithrombotic activity in several times higher than acetylsalicylic acid, however it is characterized by a later development of the desired effect: the peak of its accounts for3-10-day dosing.
Ticlopidine blocks the activity of receptor IIb-IIIa platelet aggregation than decreases.Increases the duration of bleeding and elasticity of red blood cells, reduce blood viscosity.
is absorbed in the digestive tract rapidly and almost completely.The maximum concentration of active substance in the blood observed after 2 hours, its half-life is from 13 hours to 4-5 days.Antiagregatsionnogo effect develops after 1-2 days, reaching a peak after 3-10 days of regular intake, there remains another 8-10 days after the cancellation of ticlopidine.Excreted in the urine.
produced in the form of tablets of 250 mg.
Recommended taken orally with meals 1 tablet twice a day.Take for a long time.Older patients and those with increased risk of bleeding in half the prescribed dose.
Against the background of the drug sometimes develop side effects such as allergic reactions, gastrointestinal disorders, dizziness, jaundice.
drug is not administered simultaneously with anticoagulants.
The structure and mechanism of action is similar to ticlopidine: inhibits platelet aggregation irreversibly blocking the adenosine triphosphate binding to their receptors.Unlike ticlopidine, rarely causes the development of side effects from the gastrointestinal tract, the blood system, and allergic reactions.
If ingestion is rapidly absorbed in the gastrointestinal tract.Maximum concentration in blood is determined after 1 hour.The half-life of 8 hours.The liver is modified to form the active metabolite (a product of metabolism).Excreted from the body in urine and feces.The maximum antiplatelet effect observed after 4-7 days after the start of treatment and continued for 4-10 days.
Exceeds aspirin in the prevention of thrombotic events in cardiovascular disease.
issued in the form of tablets of 75 mg.
recommended dose - one tablet of meals, once a day.Treatment long.
side effects and contraindications are similar to those of ticlopidine, however, the risk of any complications or adverse reactions with clopidogrel significantly less.
suppresses the activity of specific enzymes, platelets, resulting in them increases cAMP, which has antiplatelet effect.Also stimulates the release of the endothelium (the inner lining of blood vessels) of the substance (prostacyclin) and the subsequent blockade of the formation of thromboxane A2.
By antiplatelet effect similar to aspirin.In addition it has also koronarorasshiryayuschee properties (dilates coronary arteries at an attack of angina pectoris).
quickly and well enough (at 37-66%) absorbed from the gastrointestinal tract if swallowed.The maximum concentration observed after 60-75 minutes.The half-life is 20-40 minutes.Excreted in the bile.
issued in the form of pills or tablets 25 mg.
As an antithrombotic agent is recommended to take 1 tablet three times a day 1 hour before meal.
the treatment with this drug may develop the following side effects:
ulcerative dipyridamole has not.
Contraindications to the use of this drug is unstable angina and acute myocardial infarction stage.
inhibits platelet aggregation by preventing the binding of fibrinogen and some plasma clotting factor receptor platelets.Acting reversible: 4 hours after stopping the infusion, platelet function is reduced by half.On the prothrombin time and the APTT is not affected.
used in the treatment (in combination with acetylsalicylic acid and heparin), acute coronary syndrome and during coronary angioplasty.
release form - injection.
contraindicated during eptifibatide hemorrhagic diathesis, internal bleeding, severe hypertension, aneurysm, thrombocytopenia, severe renal impairment, and liver during pregnancy and lactation.
of the possible side effects of bleeding should be noted, bradycardia (slowing of the heart rate), lower blood pressure and levels of blood platelets, allergic reactions.
is used only in a hospital.
disturb the process of aggregation, platelet adhesion and activation, promotes the expansion of arterioles and venules, normalizes the increased vascular permeability, activates fibrinolysis (the dissolution of already formed a blood clot).
is used only in the hospital for the treatment of serious diseases: atrombangiita obliterating in the process of critical ischemia, obliterating endarteritis in an advanced stage, a severe form of Raynaud's syndrome.
issued in the form of solution for injection and infusion.
administered intravenously for the scheme.Dosages vary depending on the disease process and the severity of the patient's condition.
Contraindications Individual hypersensitivity to the drug, diseases associated with an increased risk of bleeding, severe coronary artery disease, severe arrhythmia, acute and chronic heart failure, pregnancy and lactation.
side effects are headache, dizziness, sensory disturbances, confusion, tremors, lethargy, nausea, vomiting, diarrhea, abdominal pain, decreased blood pressure, seizures, bronchospasm, pain in muscles and joints, back pain, urinary disorders,pain at the injection site phlebitis.
This is a very serious drug, it should be used only under conditions of careful monitoring of the patient.Shall not be exposed to the drug administration to the skin or inside.
increase the hypotensive effect of certain groups of antihypertensive drugs, vasodilators.
Inhibits platelet cyclooxygenase than reducing thromboxane biosynthesis.
release form - capsules of 300 mg.
recommended dose is two capsules one time per day, or 3 capsules 3 times a day.Whereas, should drink plenty of fluids.
side effects and contraindications are similar to those of aspirin.
triflusal used with caution in patients with severe hepatic or renal insufficiency.
during pregnancy and lactation is not recommended to take the drug.
There are preparations containing incorporates multiple antiplatelet agents, reinforcing or supporting each other's effects.
The most widely used are the following:
above are most commonly used in medical practice antiplatelet agents.Please note that the data contained in a paper provided to you solely for the purpose of acquaintance, not a guide to action.Please, in case of you have any complaints, do not self-medicate, and entrust their health professionals.