Antiplatelet agents are a group of drugs that prevent blood clots.
They act at the stage of blood clotting, during which sticking, or aggregation, of platelets occurs. They inhibit (suppress) the process of gluing together blood platelets, and coagulation does not occur. Different drugs in this group have different mechanisms of action to obtain an antiplatelet effect.
Today, medicine uses both long-known blood thinners and modern drugs that have fewer contraindications and less pronounced side effects. Pharmacology is constantly working on new drugs, the characteristics of which will be better than those of the previous ones.
Mechanism of action
Antiplatelet drugs (another name for this pharmacological group) have a complex way of influencing the body.
First of all, the effect is on blood clotting. The basis is the regulation of the biochemical characteristics of hemostasis.
Without going into the complex features of the process, we can say that ultimately a group of effects is achieved:
- Decreased platelet aggregation. Simply put, their sticking together is a result of an inadequate condition. The main clinical effect gives the name to the drugs of this type.
- Blood thinning. Achieved indirectly. The rheological properties of the fabric are restored. Due to this, a change in viscosity occurs, normalizing the pressure on the walls of blood vessels. Additionally, degeneration of the endothelium of arteries and veins is prevented.
However, long-term use of antiplatelet agents is not possible. Because there is a high risk of developing dangerous bleeding, which can lead to death.
Moreover, it is unacceptable to use drugs from this pharmaceutical group while taking thrombolytics (Uro-, streptokinase and other medications).
There is another type of drug, which is very similar in properties and clinical effect to the one described. These are the so-called anticoagulants. Often even doctors use both terms as synonyms, however, these are different types of drugs.
The second among those mentioned have an active effect, work faster, the effect is short-term, but much more pronounced.
Rapid blood thinning is observed, which makes anticoagulant drugs ideal for preventing the formation of blood clots, especially in emergency conditions. It makes sense, however, to approach the purpose and use with great caution.
The danger of such medications is also many times higher, which can put an end to health or even life if used incorrectly.
Attention:
The parallel administration of anticoagulants and thrombolytics is strictly prohibited. Because the risk of massive internal bleeding increases several times.
Thus, the basis of disaggregants is the ability to influence biochemical processes in the body and the composition of the blood, preventing the adhesion of its formed cells and the formation of blood clots.
Prasugrel
Prasugrel is a representative of antiplatelet agents with the same mechanism of action as clopidogrel. The indications for its use are the same. Prasugrel has an even faster and more powerful effect on platelets, but this also increases the risk of severe bleeding. This drug is also preferable for patients with diabetes.
The most dangerous side effect of prasugrel is severe bleeding. Some patients may also experience increased or decreased blood pressure, headaches, dizziness, fatigue, nausea, shortness of breath, and cough.
Acetylsalicylic acid
And its derivatives. The most common group of pharmaceuticals in medical practice with high proven effectiveness.
When compared to the other types described below, these drugs are about average in safety and effectiveness.
The classic and long-outdated Aspirin is currently still actively used, despite the high risks.
It does a good job of urgently restoring blood flow, but is absolutely not suitable for long-term use. As part of modern practice, its safer analogues are prescribed.
Aspirin-Cardio
Perhaps the most popular modification of the drug based on acetylsalicylic acid. It has a different dosage than its predecessor and is positioned as a means for the systemic, complex treatment of cardiovascular diseases.
Whether this is true or not, doctors have not come to a consensus. The main feature of Aspirin-Cardio is the possibility of long-term use with fewer risks to health and life.
The antiplatelet effect is achieved after several days of use, so the product can be considered relatively safe.
At the same time, in addition to restoring the rheological properties of liquid connective tissue, Aspirin-Cardio relieves inflammation, pain, and normalizes body temperature.
Such non-selectivity can play a cruel joke; you need to be careful when using it and carefully monitor your own feelings.
The concentration of acetylsalicylic acid in this drug is three times higher than in the classic variation of Aspirin, which also imposes a lot of restrictions. All issues are resolved at the discretion of the treating specialist.
Thrombo-ASS
In fact, there is no big difference between the old analogues based on acetylsalicylic acid and this name. In both cases, the concentration of the active substance is identical.
The difference lies in the form of release. The coating of the drug Thrombo-ACC prevents the rapid absorption of acid in the digestive tract and reduces the destructive effect of this phenomenon.
Therefore, the medication is considered not so aggressive towards the organs of the gastrointestinal tract. The advantage is quite controversial, taking into account the mass of analogues of other groups, as well as the higher cost of Trombo-ACC.
In any case, the issue of choice and appointment is decided by doctors. Unauthorized use is not possible if there is a desire to preserve health.
Aspicor
It has a minimal dosage of acetylsalicylic acid, in addition, it is considered safer than aspirin-containing analogues, not as aggressive and “clean”, therefore it can be used indefinitely as a maintenance treatment. But not in the “role” of the only medicine, but in the system.
The cost of Aspicor also makes the drug simple and affordable, because the price is not much different from that of a regular obsolete analogue.
In all cases, medications based on acetylsalicylic acid have a significant disadvantage. They are not selective.
The antiplatelet effect is complemented by an anti-inflammatory and antipyretic effect; it is logical that the drug affects many functions and organs, including the digestive tract and heart.
If used excessively, it can cause bleeding and increases the fragility and permeability of blood vessels.
"Dipyridamole"
The main effect of the drug is vasodilation, that is, dilation of blood vessels, however, when combined with other drugs, a pronounced antiplatelet effect is observed. Dipyridamole is prescribed together with Aspirin if there is a high risk of blood clots. A combination with Warfarin is also possible, which is effectively used after heart valve replacement to reduce the likelihood of embolism. With monotherapy, the effect is less pronounced.
Antiplatelet agents are drugs (list: Eliquis, Clopidogrel and others) widely used in practice.
ADP blockers
Agents that reduce the effect produced by a special substance - adenosine phosphate. This compound provokes platelet clumping through a complex bond with fibrinogen, therefore drugs of this type affect the fundamental processes of thrombus formation.
Moreover, unlike the previous ones, they are more selective and are used with less caution, although they can cause harm if used incorrectly.
Ticlopidine
A relatively old, well-studied name. The product was first synthesized in the late 70s of the last century. It is still actively used, represented by a list of trade names: Tiklid, Tiklo, Aklotin, Tagren.
The drug is used both as part of urgent care for emergency conditions, and for the treatment of chronic diseases associated with a violation of the rheological properties of the blood.
Basically, the medication is prescribed for the purpose of treating long-term conditions, preventing dangerous complications, and thrombosis. The question is open and remains at the discretion of the doctor.
Clopidogrel
There is no consensus in the medical community about what is more effective, this name or Ticlopidine. The authors hold different points of view.
However, practitioners agree that before and after surgical interventions, especially for cardiac diseases, preference should still be given to Clopidogrel, as it is the optimal combination of effectiveness and safety.
It is not prohibited to use the pharmaceutical product either in emergency conditions or for a long time, depending on the indications.
In any case, both names have significant potential and can be dangerous if used incorrectly.
Medicines to reduce the effect of ADP are also taken in isolation, as the main ones in therapy. Especially in mild cases, but more often prescribed in a system with others. Depends on the situation.
Phosphodiesterase inhibitors
They influence another mechanism of blood clot formation. They have fewer contraindications and are considered safer when compared with the previous two pharmaceutical groups.
It makes sense to use them after emergencies, surgical interventions during the rehabilitation period, or as medications for the prevention of heart attack, stroke, and acute hemodynamic disorders associated with changes in blood properties.
Common names include Dipyridamole, Triflusal. Both are relatively old. They have several trade names that differ from the main ones, for example Curantil.
They often provoke allergic reactions, therefore they require careful prescription and monitoring of the patient’s condition.
GPR blockers
Agents that reduce the sensitivity of platelet glycoprotein receptors act mildly and are relatively rarely tolerated.
The basis of the influence of medications of this type is the ability, relatively speaking, to instruct platelets not to interact with factors that provoke aggregation, that is, their sticking together.
The rheological properties of blood change slightly; the effect of HPR blockers is high, but short-lived. Therefore, it makes sense to use the remedy either within the framework of acute conditions or to select a clear regimen and dosage.
Among the names are Eptifibatide (Intergrilin), Tirofiban, and others.
Medicines of this type are most widely used when used in patients with acute conditions in a hospital. For example, with coronary insufficiency.
It also makes sense to use them in a system with classical medications based on Aspirin.
Classification of antiplatelet agents
In modern medicine, the classification of antiplatelet agents is very arbitrary. All drugs are divided into three large groups:
- direct action;
- indirect action;
- disaggregants.
The latter are the most modern drugs and have a wider spectrum of action. Disaggregants have virtually no side effects.
Arachidonic acid production inhibitors
Reduce the rate of synthesis of the named substance. In general, they are similar to the previous group of medications with an antithrombotic effect. The difference is selectivity.
This category of drugs affects many factors of platelet “clumping”, and therefore poses a much greater danger to the health and life of the patient than others.
When using it, you need to constantly monitor the person’s condition over time. To quickly adjust the dose or discontinue the drug.
Among the names: Indobufen, Ibustrin and others.
"Ticlopidine"
The action of the drug is based on blocking certain receptors responsible for thrombus formation. Normally, when ADP binds to them, the shape of the platelet changes and aggregation is stimulated, and Ticlopidine inhibits this process. A feature of this antiplatelet agent is its high bioavailability, which is achieved by a high absorption rate. After cancellation, the effect is observed for another 3-5 days. The disadvantage is a large number of side effects, among which nausea, diarrhea, thrombocytopenia and agranulocytosis are common.
Herbal remedies
Their pharmacological effectiveness has not been proven. These are medicines based on Ginkgo Biloba.
Such “medicines” do not make much sense in purchasing and using them for their intended purpose.
This also includes conventionally “folk” recipes based on ginger, St. John’s wort and others. This is not a treatment, just an amateur activity.
Herbs can be used as an aid only if the doctor agrees to it. Therapy does not tolerate creativity; it requires common sense, accurate calculations and analytical work.
Other drugs
These include those used for long-term treatment of abnormalities: Pentoxifylline (the most popular in clinical practice), Reopoliglucin (identical to the previous one, but safer and used in a wide range of cases).
Another type is complex medicines, which contain several components.
For example, Cardiomagnyl (Aspirin and magnesium, respectively), Aspigrel, Coplavix, Agrenox and others. The doctor decides whether it is worth prescribing such “explosive mixtures”.
In most cases, precise dosing is required, so it is better to give preference to two separate items.
It is safer, more effective and provides the doctor with the tools to fully control the process.
Moreover, the price of such “hybrids” is quite high, which completely eliminates any objections on this score from manufacturers. The issue is decided at the discretion of the treating cardiologist.
Indications
It is impossible to say exactly when you need to take drugs of this type. The list of antiplatelet agents is wide, and the active ingredients also differ. It's worth taking a look at the instructions.
Theoretical speculations make no sense at all, because the question in any case falls on the shoulders of the doctor.
If you present the list on average, you will get the following picture:
- Transient ischemic attacks. Temporary episodes of circulatory disorders. Localization does not play a big role.
- Emergency conditions suffered in the recent past. Heart attack, stroke. In the first case, not everything is so obvious; many medications are not allowed in this situation. In the second one too.
We are talking only about the ischemic type of disorder. Not hemorrhagic, when there was hemorrhage.
- Stable high blood pressure. Hypertension.
- Cardiac surgery performed.
- Obliterating trophic disorders in the lower extremities. For example, atherosclerosis.
- Stroke prevention (read more about primary and secondary measures in this article).
- Coronary heart disease, except in some cases where the drug can cause harm.
The list is very approximate.
Contraindications
The same applies to these grounds. The list of antiplatelet drugs is wide; it is impossible to give a complete list without taking into account the specifics of the pharmaceutical product. That's why the abstract is taken.
If we talk about something approximate again:
- Breast-feeding. The active ingredients are transmitted through milk, so use is strictly prohibited.
- Pregnancy in any phase. Will affect the condition of the mother or fetus.
- Age up to 18 years. Contraindication for the predominant number of antiplatelet agents. Use not allowed
- Hemorrhagic stroke, in which bleeding develops into the structures of the brain.
- Heart failure, at any stage. Absolute contraindication.
- Hepatic or renal dysfunction in the active phase, until the condition is compensated. Then - with great care and prudence.
- Ulcer of the stomach, duodenum, mucous membrane of other parts of the digestive tract. Because it is possible to develop bleeding, even fatal.
Even in the absence of clear reasons for refusing use, you need to carefully think about the advisability of using the medication.
Who is contraindicated for
Antiplatelet drugs are contraindicated for people with diseases such as:
- stomach ulcer in the acute stage;
- liver diseases;
- kidney disease;
- heart failure;
- all diseases that are in one way or another associated with the risk of bleeding;
- hemorrhagic stroke (bleeding in the brain).
Also, during pregnancy and lactation, you should refrain from taking these drugs.
Some drugs may have additional contraindications and side effects. The prescription of a specific medicine is strictly individual and is carried out taking into account the patient’s examinations, medical history, etc.
Important! Blood thinners are incompatible with alcohol.
Side effects
There are relatively many of them. You should start from the name and group of the product. But the question is more transparent.
Particularly common violations among the possible ones:
- Prolonged bleeding that does not stop even after minimal damage: cuts, abrasions. This is almost impossible to avoid.
- Falling blood pressure levels.
- Dizziness, disorientation in space.
- Nausea, rarely progresses to vomiting.
- Allergic reactions. Perhaps the main side effect of the use of drugs to restore the rheological properties of blood.
The intensity varies. It is minimal when a rash forms on the skin before Quincke's edema or even anaphylactic shock. Fortunately, the last option occurs as an exception.
If negative phenomena develop, it makes sense to reconsider the course and regimen of treatment or completely abandon drugs of this type, which is also more of an unfortunate rare case than the rule.
Patients are advised to closely monitor their well-being. If adverse events develop, consult your doctor again.
What are antiplatelet agents
So, what are antiplatelet agents? This is a group of medications that prevent the formation of blood clots. The active substances contained in these medications prevent platelets from sticking together, preventing blood clotting.
In addition to antiplatelet agents, disaggregants are commonly heard, what are they? These are drugs with a similar effect and are often prescribed to patients with angina pectoris.
Anticoagulants have the same principle of action, but are more aggressive and have more side effects. Pharmacology is rapidly developing and antiplatelet agents and anticoagulants are becoming more effective and safer for use.
Main indications
Antiplatelet agents are prescribed by a doctor for:
- ischemia;
- hypertension;
- after heart surgery;
- vascular diseases of the legs;
- prevention of cerebral stroke or recovery from it.
Important! All drugs in this group are prescribed only with a doctor's prescription. Unauthorized use of medications without taking into account the duration of the course and dosage is fraught with serious side effects.
