Beta blockers. Mechanism of action and classification

Preparations of the beta-blocker group are of great interest due to their amazing effectiveness. They are used for ischemic heart disease, heart failure and certain disorders of the heart.

Often, doctors prescribe them for pathological changes in the heart rhythm. Beta-blockers are drugs that block various types of (β1-, β2-, β3-) adrenergic receptors for a certain period of time. The importance of these substances can hardly be overestimated. They are considered one of a kind class of medicines in cardiology, for the development of which the Nobel Prize in Medicine was awarded.

There are selective and non-selective beta-blockers. From reference books, you can learn that selectivity is the ability to block exclusively β1-adrenergic receptors. It is important to note that it has no effect on β2-adrenergic receptors. This article contains basic information about these substances. Here you can find their detailed classification, as well as drugs and their effect on the body. So what are selective and non-selective beta blockers?

The classification of beta-blockers is quite straightforward. As noted earlier, all drugs are classified into two main groups: non-selective and selective beta-blockers.

Non-selective blockers

Nonselective beta-blockers are drugs that do not selectively block beta-adrenergic receptors. In addition, they have strong antianginal, hypotensive, antiarrhythmic and membrane stabilizing effects.

The group of non-selective blockers includes the following drugs:

• Propranolol (medicines with a similar active substance: Inderal, Obzidan);
• Bopindolol (Sandinorm);
• Levobunolol (Vistagen);
• Nadolol (Korgard);
• Obunol;
• Oxprenolol (Coretal, Trazicor);
• Pindolol;
• Sotalol;
• Thymozol (Arutimol).

The antianginal effect of this type of β-blockers is that they are able to normalize the heart rate. In addition, myocardial contractility decreases, which gradually leads to a decrease in its need for oxygen portions. Thus, the blood supply to the heart is significantly improved.

This effect is due to a slowdown in sympathetic stimulation of peripheral vessels and inhibition of the activity of the renin-angiotensin system. Moreover, at the same time, there is a minimization of the total peripheral vascular resistance and a decrease in cardiac output.

Non-selective blocker Inderal

But the antiarrhythmic effect of these substances is explained by the removal of arrhythmogenic factors. Some categories of these drugs have what is called intrinsic sympathomimetic activity. In other words, they have a powerful stimulating effect on beta-adrenergic receptors.

These drugs do not decrease or only slightly lower your resting heart rate. In addition, they do not allow an increase in the latter during exercise or under the influence of adrenergic agonists.

Cardioselective drugs

The following cardioselective beta-blockers are distinguished:

• Ormidol;
• Prinorm;
• Atenol;
• Betacard;
• Blockium;
• Catenol;
• Catenolol;
• Hypoten;
• Myocord;
• Normiten;
• Prenormin;
• Telvodin;
• Tenolol;
• Tensicor;
• Velorin;
• Falitonsin.

As you know, in the structures of the tissues of the human body there are certain receptors that respond to the hormones adrenaline and norepinephrine. At the moment, there are α1-, α2-, β1-, β2-adrenergic receptors. Recently, β3-adrenergic receptors have been described.

The location and significance of adrenergic receptors can be represented as follows:

• α1 - are located in the vessels of the body (in arteries, veins and capillaries), active stimulation leads to their spasm and a sharp increase in blood pressure;
• α2 - are considered to be a “negative feedback loop” for the system of regulation of the working capacity of body tissues - this suggests that their stimulation can lead to an immediate decrease in blood pressure;
• β1 - are located in the heart muscle, and their stimulation leads to an increase in heart rate, and also increases myocardial oxygen demand;
• β2 - placed in the kidneys, stimulation provokes the removal of bronchospasm.

Cardioselective β-blockers are active against β1-adrenergic receptors. But as for the nonselective, they equally block β1 and β2. In the heart, the ratio of the latter is 4: 1.

In other words, the stimulation of this organ of the cardiovascular system with energy is carried out mainly through β1. With the rapid increase in the dosage of beta-blockers, their specificity is gradually minimized. Only then does the selective medication block both receptors.

It is important to note that any selective or non-selective beta-blocker will equally lower blood pressure levels.

However, at the same time, cardioselective beta-blockers have much fewer side effects. It is for this reason that it is much more advisable to use them for various concomitant ailments.

Thus, they are most likely to provoke bronchospasm. This is due to the fact that their activity will not affect the β2-adrenergic receptors located in the impressive part of the respiratory system - the lungs.

It is worth noting that selective adrenergic blockers are much weaker than non-selective ones. In addition, they increase peripheral vascular resistance. It is thanks to this unique property that these drugs are prescribed to patients of cardiologists with serious peripheral circulatory disorders. This mainly concerns patients with intermittent claudication.

You should definitely pay attention to the fact that the drug called Carvedilol does not belong to the category of cardioselective drugs.

Few people know, but infrequently prescribed to lower blood pressure and eliminate arrhythmias. It is typically used to treat heart failure.

Latest generation beta blockers

There are currently three main generations of such medicines. Naturally, it is desirable to use exactly the latest (new) generation medicines. It is recommended to use them three times a day.

Carvedilol 25 mg

In addition, we must not forget that they are directly related to only a minimal amount of unwanted side effects. Innovative drugs include Carvedilol and Celiprolol. As mentioned earlier, they are quite successfully used to treat various diseases of the heart muscle.

Long-acting non-selective drugs include the following:

• Bopindolol;
• Nadolol;
• Penbutolol;
• Sotalol.

But the selective long-acting drugs include the following:

• Atenolol;
• Betaxolol;
• Epanolol.

When observing the low effectiveness of the selected medication, it is important to revise the prescribed medication.

If necessary, you should contact your personal doctor in order for him to pick up a new medicine. The whole point is that often the funds simply do not have the desired effect on the patient's body.

At the moment, more and more often, preference is given to those drugs that have precisely prolonged action. They contain active ingredients that are released gradually over an impressive period of time, smoothly affecting the health of the cardiologist's patient.

Medicines can be very effective, but this or that patient is simply not susceptible to them. In this case, everything is very individual and depends on certain characteristics of the patient's health.

It is for this reason that the treatment must be carried out with accuracy and special scrupulousness. It is very important to pay attention to all the individual characteristics of the human body.

Contraindications for use

It is for the very reason that beta-blockers have the ability to somehow affect various organs and systems (not always in a positive way), their use is undesirable and even contraindicated in some concomitant ailments of the body.

Various adverse effects and bans for use are directly related to the presence of beta-adrenergic receptors in many organs and structures of the human body.

Contraindications to the use of medications are:

• asthma;
• symptomatic lowering of blood pressure;
• decrease in heart rate (a significant slowdown in the patient's pulse);
• severe decompensated heart failure.

You should not independently select a drug from this category of drugs for the heart. It is important to remember that this can seriously harm the patient's health.

Contraindications can be relative (when the significant benefits for the therapy process outweigh the harm and the likelihood of unwanted effects):

• various diseases of the organs of the cardiovascular system;
• obstructive respiratory disease of a chronic nature;
• in persons with heart failure and slow pulse, the use is undesirable, but not prohibited;
• diabetes;
• transient lameness of the lower extremities.

Related Videos

What non-selective and selective beta-blockers (drugs from these groups) are used to treat heart disease:

For diseases when the use of beta-blockers is indicated, they should be used with extreme caution. This is especially true for women who are carrying a baby and breastfeeding. Another important point is the sudden cancellation of the selected drug: in no case is it recommended to abruptly stop drinking this or that drug. Otherwise, an unexpected phenomenon called "withdrawal syndrome" awaits a person.

Content

The action on the beta-adrenergic receptors of adrenaline and norepinephrine in diseases of the heart and blood vessels can lead to fatal consequences. In this situation, the drugs combined into groups of beta-blockers (BAB) not only make life easier, but also prolong it. Studying the subject of BAB will teach you to better understand your body while getting rid of the disease.

What are beta blockers

Under adrenergic blockers (adrenolytics) is understood a group of drugs with a general pharmacological action - neutralization of adrenaline receptors of blood vessels and heart. Medications "turn off" the receptors that respond to adrenaline and norepinephrine, and block the following actions:

• a sharp narrowing of the lumen of the blood vessels;
• increased blood pressure;
• antiallergic effect;
• bronchodilator activity (expansion of the lumen of the bronchi);
• increased blood glucose (hypoglycemic effect).

The drugs affect β2-adrenergic receptors and β1-adrenergic receptors, causing an effect opposite to adrenaline and norepinephrine. They dilate blood vessels, lower blood pressure, narrow the lumen of the bronchi, and reduce blood sugar levels. When beta1-adrenergic receptors are activated, the frequency and strength of heart contractions increase, and the coronary arteries expand.

Due to the action on β1-adrenergic receptors, the conductivity of the heart improves, the breakdown of glycogen in the liver, and the formation of energy increase. When beta2-adrenergic receptors are excited, the walls of the vessels and the muscles of the bronchi relax, insulin synthesis and the breakdown of fat in the liver are accelerated. Stimulation of beta-adrenergic receptors with catecholamines mobilizes all the forces of the body.

Preparations from the group of beta-adrenergic receptor blockers reduce the frequency and force of heart contractions, lower blood pressure, and reduce the consumption of oxygen by the heart. The mechanism of action of beta-blockers (BAB) is associated with the following functions:

1. Diastole is lengthened - by improving coronary perfusion, intracardiac diastolic pressure decreases.
2. The blood flow is redistributed from normally blood-supplied areas to ischemic areas, which increases exercise tolerance.
3. The antiarrhythmic action consists in suppressing arrhythmogenic and cardiotoxic effects, preventing the accumulation of calcium ions in the heart cells, which can impair the energy metabolism in the myocardium.

Medicinal properties

Non-selective and cardioselective beta-blockers are capable of inhibiting one or more receptors. They have opposite vasoconstrictor, hypertensive, antiallergic, bronchodilatory and hyperglycemic effects. When adrenaline binds to adrenergic receptors under the influence of adrenergic blockers, stimulation occurs, sympathomimetic internal activity increases. Depending on the type of beta-blockers, their properties are distinguished:

1. Non-selective beta-1,2-adrenergic blockers: reduce peripheral vascular resistance, myocardial contractility. Due to the drugs of this group, arrhythmia is prevented, renin production by the kidneys, and pressure are reduced. At the initial stages of treatment, the vascular tone increases, but then it decreases to normal. Beta-1,2-adrenergic blockers inhibit the adhesion of platelets, the formation of blood clots, increase the contraction of the myometrium, and activate the motility of the digestive tract. In ischemic heart disease, adrenergic receptor blockers improve exercise tolerance. In women, non-selective beta-blockers increase uterine contractility, reduce blood loss during childbirth or after surgery, and lower intraocular pressure, which allows them to be used in glaucoma.
2. Selective (cardioselective) beta1-blockers - reduce the automatism of the sinus node, reduce the excitability and contractility of the heart muscle. They reduce myocardial oxygen demand, suppress the effects of norepinephrine and adrenaline under stress. Due to this, orthostatic tachycardia is prevented, mortality in heart failure is reduced. This improves the quality of life of people with ischemia, dilated cardiomyopathy, after a stroke or heart attack. Beta1-blockers eliminate the narrowing of the capillary lumen, in bronchial asthma they reduce the risk of developing bronchospasm, in diabetes mellitus they eliminate the risk of hypoglycemia.
3. Alpha and beta-blockers - reduce cholesterol and triglyceride levels, normalize lipid profile. Due to this, the blood vessels expand, the afterload on the heart decreases, and the renal blood flow does not change. Alpha-beta-blockers improve myocardial contractility, help blood not remain in the left ventricle after contraction, but completely move into the aorta. This leads to a reduction in the size of the heart, a decrease in the degree of its deformation. In heart failure, drugs reduce ischemic attacks, normalize the cardiac index, and reduce mortality in coronary artery disease or dilatation cardiomyopathy.

Classification

To understand how drugs work, the classification of beta-blockers is useful. They are divided into non-selective, selective. Each group is divided into two more subspecies - with or without internal sympathomimetic activity. Thanks to such a complex classification, doctors have no doubts about the choice of the drug that is optimal for a particular patient.

By preferential action on beta-1 and beta-2-adrenergic receptors

By the type of influence on the types of receptors, selective beta-blockers and non-selective beta-blockers are distinguished. The former act only on the heart receptors, therefore they are also called cardioselective. Non-selective drugs affect any receptor. Non-selective beta-1,2-blockers include Bopindolol, Metipranolol, Oxprenol, Sotalol, Timolol. Selective beta-1-blockers are Bisoprolol, Metoprolol, Atenolol, Tilinolol, Esmolol. Alpha-beta-blockers include Proxodalol, Carvedilol, Labetalol.

By the ability to dissolve in lipids or water

Beta-blockers are divided into lipophilic, hydrophilic, lipohydrophilic. Fat-soluble ones are Metoprolol, Propranolol, Pindolol, Oxprenol, hydrophilic ones - Atenolol, Nadolol. Lipophilic drugs are well absorbed in the gastrointestinal tract, metabolized by the liver. In renal failure, they do not accumulate, therefore they undergo biotransformation. Lipohydrophilic or amphophilic drugs contain Acebutalol, Bisoprolol, Pindolol, Celiprolol.

Hydrophilic blockers of beta-adrenergic receptors are less well absorbed in the digestive tract, have a long half-life, and are excreted by the kidneys. It is preferable to use them in patients with hepatic insufficiency because they are eliminated by the kidneys.

By generations

Among beta-blockers, drugs of the first, second and third generations are distinguished. There are more benefits from modern drugs, their effectiveness is higher, and there are fewer harmful side effects. The first generation drugs include Propranolol (part of Anaprilin), Timolol, Pindolol, Sotalol, Alprenol. Second-generation funds - Atenolol, Bisoprolol (part of Concor), Metoprolol, Betaxolol (Lokren tablets).

Beta-blockers of the third generation additionally have a vasodilating effect (relax the blood vessels), these include Nebivolol, Carvedilol, Labetalol. The first increases the production of nitric oxide, which regulates vascular relaxation. Carvedilol additionally blocks alpha-adrenergic receptors and increases nitric oxide production, while Labetalol acts on both alpha and beta-adrenergic receptors.

List of beta blockers

Only a doctor can choose the right drug. He also prescribes the dosage and frequency of taking the medicine. List of known beta blockers:

1. Selective beta blockers

These funds act selectively on the receptors of the heart and blood vessels, therefore they are used only in cardiology.

1.1 Without intrinsic sympathomimetic activity

1.2 With intrinsic sympathomimetic activity

2. Non-selective beta blockers

These medicines do not have a selective effect, they lower arterial and intraocular pressure.

2.1 Without intrinsic sympathomimetic activity

2.2 With intrinsic sympathomimetic activity

3. Beta blockers with vasodilating properties

To solve the problems of high blood pressure, blockers of adrenergic receptors with vasodilating properties are used. They constrict blood vessels and normalize the work of the heart.

3.1 Without intrinsic sympathomimetic activity

3.2 With intrinsic sympathomimetic activity

4. BAB long-acting

Lipophilic beta-blockers - long-acting drugs work longer than antihypertensive analogues, therefore they are prescribed in a lower dosage and with a reduced frequency. These include metoprolol, which is contained in Egilok Retard, Corvitol, Emzok tablets.

5. Ultra-short-acting adrenergic blockers

Cardioselective beta-blockers - ultrashort-acting drugs have a working time of up to half an hour. These include esmolol, which is found in Breviblok, Esmolol.

Indications for use

There are a number of pathological conditions that can be treated with beta-blockers. The decision on the appointment is made by the attending physician based on the following diagnoses:

1. Exertional angina pectoris and sinus tachycardia. Beta-blockers are often the most effective remedy for the prevention of attacks and the treatment of exertional angina. The active substance accumulates in the tissues of the body, providing support to the heart muscle, which reduces the risk of recurrence of myocardial infarction. The ability of the drug to accumulate allows you to temporarily reduce the dose. The feasibility of taking BAB with exertional angina increases with the simultaneous presence of sinus tachycardia.
2. Myocardial infarction. The use of BAB in myocardial infarction leads to the limitation of the sector of cardiac muscle necrosis. This leads to a decrease in mortality, a decrease in the risk of cardiac arrest and recurrence of myocardial infarction. It is recommended to use cardioselective drugs. It is permissible to start the application immediately at the time of the patient's admission to the hospital. Duration - 1 year after myocardial infarction occurred.
3. Heart failure. Prospects for the use of BAB for the treatment of heart failure are still under study. Currently, cardiologists allow the use of drugs if this diagnosis is combined with angina pectoris, arterial hypertension, rhythm disturbances, tachysistological form of atrial fibrillation.
4. Arterial hypertension. Young people with active lifestyles often experience hypertension. In these cases, BAB can be prescribed by doctor's prescription. An additional indication for the appointment is a combination of the main diagnosis (hypertension) with rhythm disturbances, angina pectoris and after myocardial infarction. The development of hypertension into hypertension with left ventricular hypertrophy is the basis for taking BAB.
5. Heart rhythm abnormalities include abnormalities such as supraventricular arrhythmias, atrial flutter and fibrillation, and sinus tachycardia. For the treatment of these conditions, drugs from the BAB group are successfully used. A less pronounced effect is observed in the treatment of ventricular rhythm disturbances. In combination with potassium drugs, BAB is successfully used for the treatment of arrhythmias caused by glycoside intoxication.

Features of application and rules of admission

When the doctor decides on the appointment of beta-blockers, the patient must inform the doctor about the presence of such diagnoses as emphysema, bradycardia, asthma and arrhythmia. An important circumstance is pregnancy or suspicion of it. BABs are taken simultaneously with food or immediately after the end of the meal, since food reduces the severity of side effects. The dosage, regimen and duration of therapy are determined by the treating cardiologist.

During treatment, it is recommended to carefully monitor the pulse. When the frequency decreases below the established level (determined when prescribing a treatment regimen), it is required to inform the doctor about this. In addition, observation by a doctor during the course of taking drugs is a condition for the effectiveness of therapy (a specialist, depending on individual indicators, can adjust the dosage). You cannot independently cancel the intake of BAB, otherwise the side effects will be aggravated.

Side effects and contraindications of beta blockers

The appointment of BAB is contraindicated in hypotension and bradycardia, bronchial asthma, decompensated heart failure, cardiogenic shock, pulmonary edema, insulin-dependent diabetes mellitus. Relative contraindications include the following conditions:

• a chronic form of obstructive pulmonary disease in the absence of bronchospastic activity;
• peripheral vascular disease;
• transient lameness of the lower extremities.

Features of the impact of BAB on the human body can result in a number of side effects of varying severity. Patients may experience the following phenomena:

• insomnia;
• weakness;
• headache;
• breathing disorder;
• exacerbation of ischemic heart disease;
• bowel disorder;
• mitral valve prolapse;
• dizziness;
• depression;
• drowsiness;
• fatigue;
• hallucinations;
• nightmares;
• slowing down the reaction;
• anxiety;
• conjunctivitis;
• noise in ears;
• convulsions;
• raynaud's phenomenon (pathology);
• bradycardia;
• psycho-emotional disorders;
• oppression of bone marrow hematopoiesis;
• heart failure;
• palpitations;
• hypotension;
• atrioventricular block;
• vasculitis;
• agranulocytosis;
• thrombocytopenia;
• muscle and joint pain
• chest pain;
• nausea and vomiting;
• liver dysfunction;
• abdominal pain;
• flatulence;
• spasm of the larynx or bronchi;
• dyspnea;
• skin allergies (itching, redness, rash);
• cold extremities;
• sweating;
• baldness;
• muscle weakness;
• decreased libido;
• decreased or increased activity of enzymes, blood glucose and bilirubin levels;
• peyronie's disease.

Withdrawal syndrome and how to avoid it

With long-term treatment with high dosages of BAB, a sudden stop of therapy can cause a withdrawal syndrome. Severe symptoms are manifested in the form of ventricular rhythm disturbances, angina pectoris and myocardial infarction. Mild consequences are expressed in the form of an increase in blood pressure and tachycardia. Withdrawal syndrome develops within a few days after the course of therapy. To eliminate this outcome, you must follow the rules:

1. It is necessary to stop taking BAB slowly, within 2 weeks, gradually lowering the dose of the next intake.
2. During the gradual withdrawal and after the complete cessation of the intake, it is important to sharply reduce physical activity and increase the intake of nitrates (in agreement with the doctor) and other antiangial drugs. During this period, it is important to limit the intake of drugs that reduce blood pressure.

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Beta-blockers are a group of pharmaceuticals with a pronounced ability to inhibit the effect of adrenaline on special receptors, which, when excited, cause stenosis (narrowing) of blood vessels, acceleration of cardiac activity, and an indirect increase in blood pressure. Also called B-blockers, beta-blockers.

Medicines of this group are dangerous if used improperly, provoke a lot of side effects, including the risk of premature death from heart failure, sudden stop of the muscular organ (asystole).

An illiterate combination with drugs from other pharmaceutical groups (calcium, potassium channel blockers, etc.) only increases the likelihood of a negative outcome.

For this reason the appointment of treatment is carried out exclusively by a cardiologist after a complete diagnosis and clarification of the current state of affairs.

There are several key effects that play a major role and determine the effectiveness of the use of beta-blockers.

Increasing the heart rate is a biochemical process. In some way, it is triggered by the effect on special receptors located in the heart muscle, adrenal cortex hormones, the main of which is adrenaline.

Usually it is he who becomes the culprit of sinus tachycardia and other forms of supraventricular, the so-called "non-dangerous" (speaking conditionally) arrhythmias.

The mechanism of action of a B-blocker of any generation contributes to the suppression of this process at the biochemical level, due to which the increase in vascular tone does not occur, the heart rate drops, moves within normal limits, blood pressure levels out (which can be dangerous, for example, for people with adequate AD, the so-called normotonics).

The general positive effects that determine the widespread use of beta-blockers can be summarized as follows:

• Expansion of blood vessels. Due to this, the blood flow is facilitated, the speed is normalized, and the resistance of the arterial walls decreases. This indirectly helps to reduce blood pressure in patients.
• Decreased heart rate. An antiarrhythmic effect is also present. To a greater extent, it is seen on the example of use in individuals with supraventricular tachycardia.
• Hypoglycemic preventive effect. That is, drugs of the beta-blocker group do not correct the blood sugar concentration, but prevent the development of such a condition.
• Decrease in blood pressure. To acceptable numbers. This effect is far from always desirable, because the funds are used with great caution in patients with low blood pressure, or are not prescribed at all.

There is one undesirable effect that is always present, regardless of the type of medication. This is a narrowing of the lumen of the bronchi. This effect is especially dangerous for patients with diseases of the respiratory system.

Classification

The drugs can be typed according to the group of bases. Many methods have no meaning for ordinary patients and are rather understandable to practitioners and pharmacists, based on pharmacokinetics and the characteristics of the effect on the body.

The main method for classifying names is according to the prevailing potential of impact on the cardiovascular and other systems. Accordingly, three groups are distinguished.

Cardio-non-selective beta-2 adrenergic blockers (1st generation)

They have the widest scope of application, however, this also affects the number of contraindications and dangerous side effects very significantly.

A typical feature of non-selective drugs is the ability to simultaneously act on both types of adrenergic receptors: beta-1 and beta-2.

• The first is located in the heart muscle, which is why the funds are called cardioselective.
• The second is localized in the uterus, bronchi, blood vessels, and also in the cardiac structures.

For this reason, cardio-selective drugs without pharmaceutical selectivity act simultaneously on all body systems in such a direct way.

It is impossible to say that some are better and others worse. All medicines have their own field of application, and therefore are evaluated based on a specific case.

Timolol

It is not used for the treatment of cardiovascular pathologies, which does not make it less important.

Formally nonselective, the drug has the ability to gently lower the level of pressure, which makes it ideal for the treatment of a number of forms of glaucoma (an eye disease in which tonometric parameters increase).

It is considered a vital medicine and is included in the corresponding list. Used in drops.

Nadolol

A soft, cardio-selective beta-2 adrenergic blocker, which is used to treat the early stages of hypertension, corrects neglected forms with difficulty, therefore it is practically not prescribed due to the dubious action.

The main area of \u200b\u200buse of Nadolol is. It is considered a rather old drug, it is used with caution for problems with blood vessels.

Propranolol

Has a pronounced effect. The effect is predominantly cardiac.

The medication is able to reduce the frequency of heart beats, reduce myocardial contractility, and quickly affect the level of blood pressure.

Paradoxically, in order to use such a medicine, you need to be in good health, because with severe cardiac failure, a tendency to a critical drop in blood pressure and collaptoid conditions, the medication is prohibited.

Anaprilin

It is widely used in the systemic therapy of arterial hypertension, heart diseases without reducing myocardial contractility.

It is widely known for its ability to quickly and effectively stop attacks of supraventricular arrhythmias, in general.

However, it can provoke (a sharp narrowing) of the vessels, therefore it should be used with caution.

Attention:

Whisken

It is used for the treatment of arterial hypertension in the early stages, has a mild pharmacological activity.

It slightly reduces the heart rate and pumping function of the myocardium, therefore it cannot be used in the therapy of cardiac disorders itself.

Often provokes bronchospasm, narrowing of the airways. Therefore, it is almost never prescribed for patients suffering from pulmonary diseases (COPD, asthma and others).

Analog - Pindolol. Identical to Wisken, and in both cases, the composition contains the same active substance.

Nonselective beta-blockers (abbreviated as BAB) include a lot of contraindications, are very dangerous if used incorrectly.

Moreover, they often have a pronounced, even gross effect. This also requires accurate and strict dosing of drugs in this group.

Cardioselective beta-1 blockers (2nd generation)

Beta-1 adrenergic blockers target the receptors of the same name in the heart, which makes them drugs of a narrow focus. Efficiency does not suffer, rather the opposite.

Initially, they are considered safer, although they still cannot be taken on their own. Especially in combinations.

It is used to a greater extent for the relief of acute conditions associated with a violation of the heart rhythm.

Effectively eliminates various deviations, not only of the supraventricular type. In some cases, it is used in parallel with Amiodarone, which is considered the main one in the treatment of heart rate disorders and belongs to a different group.

It is not suitable for permanent use, because, as it is relatively difficult to tolerate, it provokes "side effects".

Gives the quick desired result. The beneficial effect appears after an hour or less.

Bioavailability also depends on the individual characteristics of the organism, the current functional characteristics of the patient's body.

Cardioselective beta-blocker for systematic administration. Unlike Metoprolol, it starts working after 12 hours, but the effect lasts longer.

The medication is suitable for long-term use, the main result is the normalization of blood pressure levels and heart rate. Prevention of recurrence of arrhythmia.

Talinolol (Cordanum)

It does not fundamentally differ from Metoprolol. Has identical readings. It is used in the relief of acute conditions.

The list of beta-blockers is incomplete; only the most common and frequently occurring names of medicines are presented. There are many analogs and identical drugs.

Selection "by eye" almost never yields results; a thorough diagnosis is required.

But even in this case, there is no guarantee that the drug will fit. Therefore, hospitalization for a short period of time is strongly recommended to prescribe a quality course of treatment.

Latest generation beta blockers

Modern beta-blockers of the last, third generation are represented by a short list of "Celiprolol" and "Carvedilol".

They have properties to act on both beta and alpha adrenergic receptors, which makes them the widest in terms of application and pharmaceutical activity.

Celiprolol

It is used to quickly lower blood pressure. It can be used for a long time.

It also influences the nature of the functional activity of the heart muscle. It is prescribed for patients of different age groups.

Carvedilol

Since it is able to block alpha-receptors, it effectively dilates blood vessels.

It is used not only in the treatment of diseases of the cardiovascular system, but also as a prophylactic agent for the normalization of coronary blood flow, which is absolutely necessary when it comes to preventing heart attack.

An additional effect of mixed beta-blockers is the ability to eliminate extrapyramidal disorders.

Sometimes this action is used to correct abnormalities when taking antipsychotics. Nevertheless, it is extremely risky, because Carvedilol has not received widespread use as medicines to replace Cyclodol and others.

The choice of a specific name, group, should be based on the diagnostic results.

Indications

The grounds for use depend on the type of medication and the specific name. Summarizing several types of drugs, the following picture emerges.

• Primary hypertension. It is caused by the actual diseases of the heart and blood vessels, accompanied by a persistent gradual increase in blood pressure. When chronic, the disorder is difficult to correct.
• Secondary or. It is caused by a violation of hormonal levels, kidney function. It can be benign, indistinguishable from primary or malignant with a rapid jump in blood pressure to critical levels and the preservation of a crisis status for an indefinite period of time, up to the destruction of target organs and death.
• Arrhythmias of different types. Mostly supraventricular. To interrupt an acute condition and prevent the development of further repeated episodes, relapses of the disorder.
• ... The antianinal effect of the drugs is based on reducing the need for the heart and its structures for oxygen and nutrients. However, the need for use is associated with certain risks, it is worth assessing the contractility of the myocardium and the tendency to heart attack.
• in the initial stages. The use is due to the same antianginal action.

As part of additional use, as an auxiliary profile, beta-blockers are prescribed for pheochromocytoma (tumor of the adrenal cortex that synthesizes norepinephrine).

It is possible to use it in the current hypertensive crisis to normalize the heart rhythm, vasodilation (the vasodilation effect is inherent mainly in mixed beta-blockers. Like Carvidelol, which also affect alpha receptors).

Contraindications

In no case are medicines of the specified pharmaceutical group used in the presence of at least one of the grounds below:

• Severe arterial hypotension.
• Bradycardia. A drop in heart rate to 50 beats per minute or less.
• Myocardial infarction. Because beta-blockers tend to weaken the contractile ability, which in this case is unacceptable and deadly.
• , defects of the conducting system of the heart, impaired movement of the impulse along the bundle of His.
• before the condition is corrected.

Relative contraindications require consideration. In some cases, drugs can be prescribed, but with caution:

• Bronchial asthma, severe respiratory failure.
• Pheochromocytoma without the simultaneous use of alpha-blockers.
• Chronic obstructive pulmonary disease.
• Current intake of antipsychotic drugs (neuroleptics). Not always.

With regard to pregnancy, breastfeeding, use is not recommended. Unless in extreme cases, when the potential benefit outweighs the potential damage. Most often these are dangerous conditions that can harm the health or even take the life of the patient.

Side effects

There are a lot of undesirable phenomena. But they do not always appear and are far from equal. Some drugs are easier to tolerate, while others are much harder.

Among the generalized list are the following violations:

• Dry eyes.
• Weakness
• Drowsiness.
• Headache.
• Decreased orientation in space.
• Tremor, trembling limbs.
• Bronchospasm.
• Dyspeptic symptoms. Belching, heartburn, loose stools, nausea, vomiting.
• Hyperhidrosis. Increased sweating.
• Itching, rash, urticaria.
• , drop in blood pressure, heart failure and other cardiac events, potentially life-threatening.
• There are side effects on the part of laboratory blood parameters, but it is impossible to detect them on our own.

The list of beta-blocker drugs has more than a dozen names, the fundamental difference between them is not always noticeable.

In any case, it is necessary to consult a cardiologist to select a suitable therapeutic course. You can do harm on your own and only make it worse.

BAB are a group of pharmacological drugs, when introduced into the human body, beta-adrenergic receptors are blocked.

Beta-adrenergic receptors are classified into three subtypes:

beta1-adrenergic receptors, which are located in the heart and through which the stimulating effects of catecholamines on the activity of the heart - pump are mediated: increased sinus rhythm, improved intracardiac conduction, increased myocardial excitability, increased myocardial contractility (positive chrono-, dromo-, batmo-, inotropic effects) ;

beta2-adrenergic receptors, which are located mainly in the bronchi, smooth muscle cells of the vascular wall, skeletal muscles, in the pancreas; when they are stimulated, broncho- and vasodilatory effects, relaxation of smooth muscles and insulin secretion are realized;

beta3-adrenergic receptors, localized mainly on the membranes of adipocytes, are involved in thermogenesis and lipolysis.

The idea of \u200b\u200busing beta-blockers as cardioprotectors belongs to the Englishman J. W. Black, who was awarded the Nobel Prize in 1988, together with the co-workers, creators of beta-blockers. The Nobel committee considered the clinical relevance of these drugs "the greatest breakthrough in the fight against heart disease since the discovery of digitalis 200 years ago."

Classification

Preparations from the group of beta-blockers differ in the presence or absence of cardioselectivity, internal sympathetic activity, membrane stabilizing, vasodilating properties, solubility in lipids and water, influence on platelet aggregation, as well as duration of action.

Currently, clinicians identify three generations of beta-blocking drugs.

1st generation - nonselective beta1- and beta2-blockers (propranolol, nadolol), which, along with negative foreign, chrono- and dromotropic effects, have the ability to increase the tone of smooth muscles of the bronchi, vascular wall, myometrium, which significantly limits their use in clinical practice.

2nd generation - cardioselective beta1-adrenergic blockers (metoprolol, bisoprolol), due to their high selectivity in relation to beta1-adrenergic receptors of the myocardium, have a more favorable tolerance with long-term use and a convincing evidence base for a long-term prognosis of life in the treatment of hypertension, ischemic heart disease and CHF.

Drugs III generation - celiprolol, bucindolol, carvedilol have additional vasodilating properties due to blockade of alpha-adrenergic receptors, without internal sympathomimetic activity.

Table. Classification of beta-blockers.

Effects

The ability to block the effect of mediators on beta1-adrenergic receptors of the myocardium and weakening the effect of catecholamines on membrane adenylate cyclase of cardiomyocytes with a decrease in the formation of cyclic adenosine monophosphate (cAMP) determine the main cardiotherapeutic effects of beta-blockers.

Antiischemic the effect of beta-blockers due to a decrease in myocardial oxygen demand, due to a decrease in heart rate (HR) and the strength of heart contractions that occur when the beta-adrenergic receptors of the myocardium are blocked.

Beta-blockers simultaneously provide an improvement in myocardial perfusion by reducing the end-diastolic pressure in the left ventricle (LV) and increasing the pressure gradient that determines coronary perfusion during diastole, the duration of which increases as a result of a decrease in the heart rate.

Antiarrhythmic the action of beta-blockers, based on their ability to reduce the adrenergic effect on the heart, leads to:

decrease in heart rate (negative chronotropic effect);

decrease in the automatism of the sinus node, AV connection and the Hisa-Purkinje system (negative batmotropic effect);

reduction in the duration of the action potential and the refractory period in the His-Purkinje system (the QT interval is shortened);

deceleration of conductivity in the AV connection and an increase in the duration of the effective refractory period of the AV connection, lengthening of the PQ interval (negative dromotropic effect).

Beta-blockers increase the threshold of ventricular fibrillation in patients with acute myocardial infarction and can be considered as a means of preventing fatal arrhythmias in the acute period of myocardial infarction.

Antihypertensive act beta-blockers due to:

a decrease in the frequency and strength of heart contractions (negative chrono- and inotropic effect), which in total leads to a decrease in cardiac output (MOC);

a decrease in secretion and a decrease in the concentration of renin in plasma;

restructuring of the baroreceptor mechanisms of the aortic arch and carotid sinus;

central suppression of sympathetic tone;

blockade of postsynaptic peripheral beta-adrenergic receptors in the venous vascular bed, with a decrease in blood flow to the right heart and a decrease in MOC;

competitive antagonism with catecholamines for receptor binding;

an increase in the level of prostaglandins in the blood.

The effect on beta2-adrenergic receptors determines a significant part of the side effects and contraindications to their use (bronchospasm, peripheral vasoconstriction). A feature of cardioselective beta-blockers in comparison with nonselective ones is their greater affinity for beta1-receptors of the heart than for beta2-adrenergic receptors. Therefore, when used in small and medium doses, these drugs have a less pronounced effect on the smooth muscles of the bronchi and peripheral arteries. It should be borne in mind that the degree of cardioselectivity is not the same for different drugs. The index ci / beta1 to ci / beta2, characterizing the degree of cardioselectivity, is 1.8: 1 for non-selective propranolol, 1:35 for atenolol and betaxolol, 1:20 for metoprolol, 1:75 for bisoprolol. However, it should be remembered that the selectivity is dose-dependent, it decreases with increasing dose of the drug.

In accordance with the clinically significant pharmacokinetic properties of beta-blockers, drugs are divided into 3 groups (see Table)

Table. Features of the metabolism of beta-blockers.

* lipophilicity increases the penetration through the blood-brain barrier; with blockade of central beta-1 receptors, the tone of the vagus increases, which is important in the mechanism of antifibrillatory action. There is evidence (Kendall M.J. et al., 1995) that the reduction in the risk of sudden death is more pronounced with the use of lipophilic beta-blockers.

Indications:

Ischemic heart disease (MI, sninocardia)

Tachyarrhythmias

Dissecting aneurysm

Bleeding from varicose veins of the esophagus (prevention of cirrhosis of the liver - propranolol)

Glaucoma (timolol)

Hyperthyroidism (propranolol)

Migraine (propranolol)

Alcohol withdrawal (propranolol)

Rules for prescribing β-AB:

start therapy with low doses;

increase the dose no more often than at 2-week intervals;

to carry out treatment at the maximum tolerated dose;

1–2 weeks after the start of treatment and 1–2 weeks after the completion of dose titration, monitoring of blood biochemical parameters is necessary.

When a number of symptoms appear while taking β-blockers, they are guided by the following recommendations:

with an increase in the symptoms of heart failure, the dose of a β-blocker should be halved;

in the presence of fatigue and / or bradycardia, reduce the dose of β-blocker;

in the event of a serious deterioration in well-being, reduce the dose of β-blocker by half or stop treatment;

at heart rate< 50 уд./мин следует снизить дозу β-адреноблокатора вдвое; при значительном снижении ЧСС лечение прекратить;

with a decrease in heart rate, a revision of the doses of other drugs is required to reduce the pulse;

in the presence of bradycardia, it is necessary to timely monitor the ECG for early detection of heart block.

Side effectsall β-blockers are divided into cardiac (bradycardia, arterial hypotension, development of atrioventricular blockade) and extracardiac (dizziness, depression, nightmares, insomnia, memory impairment, fatigue, hyperglycemia, hyperlipidemia, muscle weakness, impaired potency).

Stimulation of β2 -adrenergic receptors leads to increased glycogenolysis in the liver and skeletal muscle, gluconeogenesis and insulin release. Therefore, the use of nonselective β-ABs can be accompanied by an increase in glycemia and the emergence of insulin resistance. At the same time, in cases of type 1 diabetes mellitus, nonselective β-ABs increase the risk of "latent hypoglycemia", since after insulin administration they inhibit the return of glycemic levels to normal. Even more dangerous is the ability of these drugs to induce a paradoxical hypertensive reaction, which may be accompanied by reflex bradycardia. Such changes in the state of hemodynamics are associated with a significant increase in the level of adrenaline against the background of hypoglycemia.

Another problem that may arise in the case of long-term use of non-selective β-ABs is a violation of lipid metabolism, in particular, an increase in the concentration of very low density lipoproteins, triglycerides and a decrease in the content of antiatherogenic high density lipoprotein cholesterol. These changes are likely to result from a weakening of the effects of lipoprotein lipase, which is normally responsible for the metabolism of endogenous triglycerides. Stimulation of unblocked α-adrenergic receptors against the background of blockade of β1 and β2-adrenergic receptors leads to inhibition of lipoprotein lipase, while the use of selective β-AB makes it possible to prevent these disorders of lipid metabolism. It should be noted that the beneficial effect of β-AB as cardioprotective agents (for example, after acute myocardial infarction) is much more significant and more important than the consequences of the adverse effect of these drugs on lipid metabolism.

Contraindications

Absolute contraindications for β-AB are bradycardia (< 50–55 уд./мин), синдром слабости синусового узла, АВ-блокада II–III степени, гипотензия, острая сосудистая недостаточность, шок, тяжелая бронхиальная астма. Хронические обструктивные заболевания легких в стадии ремиссии, компенсированные заболевания периферических артерий в начальных стадиях, депрессия, гиперлипидемия, АГ у спортсменов и сексуально активных юношей могут быть относительными противопоказаниями для применения β-АБ. Если существует необходимость их назначения по показаниям, предпочтительно назначать малые дозы высокоселективных β-АБ.

Antagonistscalcium(AK) - a large group of drugs of various chemical structure, the common property of which is the ability to reduce the flow of ions calciuminto vascular smooth muscle cells and cardiomyocytes, by interaction with slow calciumchannels (L-type) of cell membranes. As a result, smooth muscles of arterioles relax, blood pressure and total peripheral vascular resistance decrease, strength and heart rate decrease, atrio-ventricular (AV) conduction slows down.

AK classification:

Note: SR and ER are sustained release formulations

The main pharmacological effects of calcium antagonists:

Antihypertensive effect (typical for derivatives of dihydropyridine, phenylalkylamine, benzothiazepine)

Antianginal (typical for dihydropyridine, phenylalkylamine, benzothiazepine derivatives)

Antiarrhythmic action (typical for drugs verapamil and diltiazem).

The drugs belonging to different groups differ in the severity of their action on the heart and on the peripheral vessels. So, dihydropyridine AAs act to a greater extent on the vessels, and therefore they have a more pronounced hypotensive effect, and practically do not affect the conductivity of the heart and its contractile function. Verapamil has a great affinity for calciumchannels of the heart, in connection with which it reduces the strength and heart rate, worsens AV conduction, and to a lesser extent affects the vessels, therefore its hypotensive effect is less pronounced than that of dihydropyridine AA. Diltiazem acts on the heart and blood vessels in equal measure. Since verapamil and diltiazem have a certain similarity to each other, they are conventionally combined into a subgroup of nondihydropyridine AAs. Within each AK group, short-acting drugs and prolongeddrugs.

Currently, AK are one of the main classes of drugs that can be used for initial therapy of hypertension. According to comparative studies (ALLHAT, VALUE), prolonged AK demonstrated a hypotensive effect equal to the antihypertensive activity of ACE inhibitors, angiotensin II receptor antagonists, diuretics and β-blockers. The maximum decrease in blood pressure when taking AA is noted with low-root, volume-dependent AH. AK in comparison with antihypertensive drugs of other classes (ACE inhibitors, diuretics and β-blockers) not only have an equal hypotensive effect, but equally reduce the frequency of "major cardiovascular complications" - myocardial infarction, cerebral stroke and cardiovascular mortality. Left ventricular (LV) myocardial hypertrophy is an independent risk factor in hypertension. AK reduce LV hypertrophy, improve its diastolic function, especially in patients with hypertension and coronary artery disease. An important aspect of the organoprotective action of AA is the prevention or slowdown of vascular remodeling (the rigidity of the vascular wall decreases, endothelium-dependent vasodilation is improved due to an increase in NO production).

A special approach is required in the treatment of hypertension in patients with diabetes mellitus (DM), since they have a particularly high risk of cardiovascular complications. With a combination of hypertension and diabetes, the optimal antihypertensive drug should not only ensure the achievement of target blood pressure values, but also have pronounced organoprotective properties and be metabolically neutral. Prolonged dihydropyridine AAs (felodipine, amlodipine, etc.), along with ACE inhibitors and ARBs, are the drugs of choice in the treatment of hypertension in patients with diabetes, since they not only effectively reduce blood pressure, but also have pronounced organoprotective properties, including nephroprotective effect (reduce the severity of microalbuminuria, slow down the progression of diabetic nephropathy), and are also metabolically neutral. In most patients with hypertension and diabetes, the target blood pressure level can be achieved only with the use of a combination of antihypertensive drugs. The most rational in this clinical situation are combinations of AK with an ACE inhibitor or ARB. Currently, it has been convincingly shown (ASCOT-BPLA) that the use of drugs with favorable metabolic effects or metabolically neutral for the treatment of hypertension reduces the risk of developing diabetes by 30% compared to other antihypertensive drugs (thiazide diuretics, β-blockers). The results of these studies are reflected in the European clinical guidelines for the treatment of hypertension. So, in the treatment of hypertension in patients with a high risk of developing diabetes (burdened family history of diabetes, obesity, impaired glucose tolerance), it is recommended to use drugs with a favorable metabolic profile (for example, prolonged AC, ACE inhibitors or ARBs).

Indications:

Ischemic heart disease (angina pectoris)

Hypertension in elderly patients

Systolic hypertension

Hypertension and peripheral arterial disease

AH and carotid atherosclerosis

AH associated with COPD and asthma BR

• Hypertension in pregnant women

  Hypertension and supraventricular tachycardia *

  Hypertension and migraine *

Contraindications:

AV block II-III degree *

* - only for non-dihydropyridine AA

Relative contraindications:

* - only for non-dihydropyridine AA

Effective combinations

Most multicenter studies have shown that in 70% of patients with AH, a combination of two or three antihypertensive drugs must be prescribed to achieve target blood pressure levels. Among the combinations of the two drugs, the following are considered effective and safe:

aCE inhibitors + diuretic,

BAB + diuretic,

AK + diuretic,

sartans + diuretic,

sartans + ACE inhibitors + diuretic

AK + ACE inhibitors,

Under hypertensive crisisunderstand all cases of a sudden and significant increase in blood pressure, accompanied by the appearance or aggravation of already existing cerebral, cardiac or general vegetative symptoms, the rapid progression of dysfunction of vital organs.

Criteria for a hypertensive crisis:

relatively sudden onset;

individually high rise in blood pressure;

the appearance or intensification of complaints of a cardiac, cerebral or general vegetative nature.

In the USA and Europe, a clinical classification, which is simple for the choice of patient management tactics, has become widespread, in which hypertensive crises are divided into complicated and uncomplicated ones.

Complicated hypertensive crises characterized by acute or progressive damage to target organs (POM), pose a direct threat to the patient's life and require an immediate, within 1 hour, decrease in blood pressure.

Uncomplicated hypertensive crises, there are no signs of acute or progressive POM, pose a potential threat to the patient's life, require a rapid, within a few hours, decrease in blood pressure.

Treatment of hypertensive crises

With the drug treatment of hypertensive crises, it is necessary to solve the following tasks:

Stopping an increase in blood pressure. In this case, it is necessary to determine the degree of urgency of starting treatment, choose the drug and the method of its administration, set the required rate of blood pressure decrease, and determine the level of permissible decrease in blood pressure.

Ensuring adequate control over the patient's condition during the period of blood pressure decrease. Timely diagnosis of complications or excessive decrease in blood pressure is required.

Consolidation of the achieved effect. For this, the same drug is usually prescribed, with the help of which blood pressure was reduced, if impossible - other antihypertensive drugs. Time is determined by the mechanism and duration of the selected drugs.

Treatment of complications and concomitant diseases.

Selection of the optimal dosage of drugs for maintenance treatment.

Carrying out preventive measures to prevent crises.

Antihypertensives.

Antihypertensive drugs are a group of drugs used to restore low blood pressure to normal. An acute drop in blood pressure (collapse, shock) can be the result of blood loss, trauma, poisoning, infectious diseases, heart failure, dehydration, etc. In addition, chronic arterial hypotension can occur as an independent disease. To eliminate arterial hypotension, drugs are used:

increasing the volume of circulating blood - plasma substitutes, saline solutions;

vasoconstrictor agents (caffeine, cordiamine, alpha-adrenergic agonists, glucocorticoids, mineralocorticoids, angiotensinamide);

improving tissue microcirculation and eliminating hypoxia - ganglion blockers, a-blockers;

non-glycoside cardiotonics (dobutamine, dopamine);

agents that have a tonic effect on the central nervous system - tinctures of lemongrass, ginseng, zamaniha, aralia; extracts of Eleutherococcus and Rhodiola rosea.

Drugs used for uncomplicated hypertensive crises

Parenteral therapy for complicated hypertensive crises

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Adrenergic blockers constitute a large group of drugs that block adrenaline and norepinephrine receptors. They are widely used in therapeutic and cardiological practice, they are prescribed everywhere for patients of different ages, but mainly for elderly people, who are most likely to have vascular and heart damage.

The functioning of organs and systems is subject to the action of a variety of biologically active substances that affect certain receptors and cause certain changes - expansion or narrowing of blood vessels, a decrease or increase in the strength of heart contractions, spasm of the bronchi, etc. In certain situations, the action of these hormones is excessive or it becomes necessary to neutralize their effects in connection with the emerging disease.

Epinephrine and norepinephrine are secreted by the adrenal medulla and have a wide range of biological effects - vasoconstriction, increased pressure, increased blood sugar, dilated bronchi, relaxation of intestinal muscles, dilated pupils. These phenomena are possible due to the release of hormones in the peripheral nerve endings, from which the necessary impulses go to organs and tissues.

In various diseases, it becomes necessary to block adrenergic impulses to eliminate the effects of adrenaline and norepinephrine. For this purpose, adrenergic blockers are used, the mechanism of action of which is the blockade of adrenergic receptors, protein molecules to adrenaline and norepinephrine, while the formation and release of the hormones themselves is not disturbed.

Classification of adrenergic blocking substances

There are alpha-1, alpha-2, beta-1 and beta-2 receptors located in the vascular walls and the heart. Depending on the type of inactivated receptors, alpha and beta blockers are released.

Alpha-adrenergic blockers include phentolamine, tropafen, pyrroxan, drugs that inhibit the activity of beta receptors - anaprilin, labetalol, atenolol and others. The drugs of the first group turn off only those effects of adrenaline and norepinephrine, which are mediated by alpha receptors, the second, respectively, by beta-adrenergic receptors.

To increase the effectiveness of treatment and eliminate some side effects, selective adrenergic blocking substances have been developed that act strictly on a specific type of receptor (α1,2, β1,2).

Groups of adrenergic blocking agents

1. Alpha blockers:
   • α -1-blockers - prazosin, doxazosin;
   • α -2-blockers - yohimbine;
   • α-1,2-adrenergic blockers - phentolamine, pyrroxan, nicergoline.

1. Beta-blockers:
   • cardioselective (β-1) adrenergic blockers - atenolol, bisoprolol;
   • non-selective β-1,2-blockers - propranolol, sotalol, timolol.

1. Blockers of both alpha- and beta-adrenergic receptors - labetalol, carvedilol.

Alpha blockers

Alpha-adrenergic blockers (alpha-AB), which block different types of alpha-receptors, act in the same way, realizing the same pharmacological effects, and the difference in their use consists in the number of side reactions, which, for obvious reasons, are more in alpha 1,2 -blockers, because they are directed to all adrenaline receptors at once.

The drugs of this group contribute to the expansion of the lumen of blood vessels, which is especially noticeable in the skin, mucous membranes, intestinal wall, kidneys. With an increase in the capacity of the peripheral bloodstream, the resistance of the vascular walls and systemic arterial pressure decrease, therefore, microcirculation and blood flow at the periphery of the circulatory system is significantly facilitated.

Decreased venous return due to expansion and relaxation of the "periphery" contributes to reducing the load on the heart, because of which its work becomes easier, and the condition of the organ improves. Alpha-adrenergic blockers help to reduce the degree by facilitating the work of the organ, do not cause tachycardia, which often occurs when using a number.

In addition to the vasodilator and hypotensive effect, alpha-AB for the better change the indicators of fat metabolism, contributing to a decrease in the total and increasing the concentration of antiatherogenic fat fractions, therefore, their appointment is possible with obesity and dyslipoproteinemias of various origins.

When using α-blockers, carbohydrate metabolism also changes. The cells become more sensitive to insulin, so sugar is better and faster absorbed by them, which prevents hyperglycemia and normalizes the indicator. This effect is very important for patients.

A special area of \u200b\u200bapplication of alpha-blockers is urological pathology. So, α-adrenergic blocking drugs are actively used for hyperplasia of the prostate due to the ability to eliminate some of its symptoms (nocturnal urination, partial emptying of the bladder, burning sensation in the urethra).

Alpha-2-adrenergic blockers have a weak effect on the vascular walls and heart, therefore they are not popular in cardiology, however, in the course of clinical trials, a striking effect on the genital sphere was noticed. This fact became the reason for their appointment for sexual dysfunction in men.

Indications for the use of alpha-AB are:

• Disorders of peripheral blood flow -, acrocyanosis, diabetic microangiopathy);
• Pheochromocytoma;
• Trophic lesions of the soft tissues of the extremities, in particular, with atherosclerosis, frostbite, bedsores;
• The consequences of the postponed, vascular dementia;
• BPH;
• Anesthesia and surgery - for the prevention of hypertensive crises.

Prazosin, doxazosin are actively used in the treatment of hypertension, tamsulosin, terazosin effective for prostatic hyperplasia. Pyrroxan has a sedative effect, improves sleep, relieves itching in allergic dermatitis. In addition, due to the ability to inhibit the activity of the vestibular apparatus, pyrroxane can be prescribed for sea and air sickness. In drug addiction practice, it is used to reduce the manifestations of morphine withdrawal syndrome and alcohol withdrawal.

Nicergoline used by neurologists in the treatment of the brain, indicated for acute and chronic disorders of cerebral blood flow, transient ischemic attacks, can be prescribed for head injuries, for the prevention of migraine attacks. It has an excellent vasodilator effect, improves blood circulation in the extremities, therefore it is used for peripheral pathology (Raynaud's disease, atherosclerosis, diabetes, etc.).

Beta-blockers

Beta-blockers (beta-AB) used in medicine are directed either at both types of beta receptors (1,2), or at beta-1. The former are called non-selective, the latter are called selective. Selective beta-2-ABs are not used for therapeutic purposes, since they have no significant pharmacological effects, the rest are widespread.

basic action of beta blockers

Beta-blockers have a wide range of effects associated with the inactivation of beta receptors in blood vessels and the heart. Some of them are capable of not only blocking, but also to some extent activating receptor molecules - the so-called internal symatomimetic activity. This property is noted for non-selective drugs, while selective beta-1-blockers lack it.

Beta-blockers are widely used in the treatment of diseases of the cardiovascular system -,. They reduce the frequency of heart contractions, reduce blood pressure, have an analgesic effect when. A decrease in concentration of attention is associated with the suppression of the central nervous system by certain drugs, which is important for transport drivers and people engaged in strenuous physical and mental work. At the same time, this effect can be used for anxiety disorders.

Non-selective beta blockers

Means of non-selective action contribute to the reduction of heart contractions, somewhat reduce the total vascular peripheral resistance, and have a hypotensive effect. The contractile activity of the myocardium decreases, therefore, the amount of oxygen required for the work of the heart also becomes less, which means that resistance to hypoxia increases (for example).

By reducing the vascular tone, reducing the release of renin into the bloodstream, the hypotensive effect of beta-AB is achieved in hypertension. They have an antihypoxic and antithrombotic effect, reduce the activity of excitation centers in the cardiac conduction system, preventing arrhythmias.

Beta-blockers tone the smooth muscles of the bronchi, uterus, gastrointestinal tract and, at the same time, relax the sphincter of the bladder.

The exerted effects allow beta-blockers to reduce the likelihood of occurrence and sudden coronary death, according to some reports, by half. Patients with heart ischemia, when using them, note that pain attacks become more rare, and resistance to physical and mental stress increases. In hypertensive patients, when taking non-selective beta-AB, the risk of myocardial ischemia becomes less.

The ability to increase the tone of the myometrium allows the use of drugs of this group in obstetric practice for the prevention and treatment of atonic bleeding during childbirth, blood loss during operations.

Selective beta-blockers

location of β-adrenergic receptors

Selective beta-blockers act primarily on the heart. Their influence comes down to:

1. Decrease in heart rate;
2. Decrease in the activity of the sinus node, pathways and myocardium, due to which an antiarrhythmic effect is achieved;
3. Decrease in oxygen required by the myocardium - antihypoxic effect;
4. Decrease in systemic pressure;
5. Limiting the focus of necrosis during a heart attack.

With the appointment of beta-blockers, the load on the heart muscle and the volume of blood entering the aorta from the left ventricle at the time of systole decreases. In patients taking selective drugs, the risk of tachycardia is reduced when changing from a supine position to an upright position.

The clinical effect of cardioselective beta-blockers is a decrease in the frequency and severity of angina attacks, an increase in resistance to physical and psycho-emotional stress. In addition to improving the quality of life, they reduce mortality from cardiac pathology, the likelihood of hypoglycemia in diabetes, bronchospasm in asthmatics.

The list of selective beta-AB includes many names, including atenolol, acebutolol, bisoprolol, metoprolol (egilok), nebivolol. Non-selective blockers of adrenergic activity include nadolol, pindolol (wisken), propranolol (anaprilin, obzidan), timolol (eye drops).

The indications for the appointment of beta-blockers are:

• Increased systemic and intraocular (glaucoma) pressure;
• Ischemic heart disease (angina pectoris, myocardial infarction);
• Migraine prevention;
• Pheochromocytoma, thyrotoxicosis.

Beta-blockers are a serious group of drugs that can only be prescribed by a doctor, but in this case, side reactions are possible. Patients may experience headache and dizziness, complain of poor sleep, weakness, and a decreased emotional background. A side effect can be hypotension, a slowing down of the heart rate or its violation, allergic reactions, shortness of breath.

Non-selective beta-blockers among the side effects have a risk of cardiac arrest, visual impairment, fainting, signs of respiratory failure. Eye drops can cause irritation of the mucous membrane, a burning sensation, lacrimation, and inflammation in the tissues of the eye. All these symptoms require consultation with a specialist.

When prescribing beta-blockers, the doctor will always take into account the presence of contraindications, of which there are more in the case of selective drugs. It is impossible to prescribe substances that block adrenergic receptors to patients with pathology of conduction in the heart in the form of blockages, bradycardia, they are prohibited in cardiogenic shock, individual hypersensitivity to drug components, acute or chronic decompensated heart failure, bronchial asthma.

Selective beta-blockers are not prescribed for pregnant women and nursing mothers, as well as for patients with distal blood flow pathology.

The use of alpha-beta-blockers

Preparations from the group of α, β-blockers help to lower systemic and intraocular pressure, improve fat metabolism (reduce the concentration of cholesterol and its derivatives, increase the proportion of antiatherogenic lipoproteins in the blood plasma). By expanding the vessels, reducing the pressure and load on the myocardium, they do not affect the blood flow in the kidneys and the total peripheral vascular resistance.

Medicines acting on two types of receptors for adrenaline increase myocardial contractility, due to which the left ventricle completely ejects the entire volume of blood into the aorta at the time of its contraction. This effect is important when the heart is enlarged, its cavities expand, which often happens with heart failure, heart defects.

When prescribed to patients with heart failure, α, β-adrenergic blocking substances improve heart function, making patients more resistant to physical and emotional stress, prevent tachycardia, and angina attacks with heart pain become more rare.

Having a positive effect, primarily on the heart muscle, α, β-blockers reduce mortality and the risk of complications in acute myocardial infarction, dilated cardiomyopathy. The reasons for their appointment are:

1. Hypertensive disease, including at the time of a crisis;
2. Congestive heart failure - in combination with other groups of drugs according to the scheme;
3. Chronic ischemia of the heart in the form of stable angina pectoris;
4. Some types of heart rhythm disturbances;
5. Increased intraocular pressure - applied topically in drops.

While taking drugs of this group, side effects are possible, which reflect the effect of the drug on both types of receptors - both alpha and beta:

• Dizziness and headache associated with a decrease in blood pressure, fainting is possible;
• Weakness, feeling tired;
• Decrease in heart rate, impairment of impulse conduction through the myocardium up to blockade;
• Depressive states;
• Changes in blood counts - a decrease in leukocytes and platelets, which is fraught with bleeding;
• Swelling and weight gain;
• Shortness of breath and bronchospasm;
• Allergic reactions.

This is an incomplete list of possible effects, about which the patient can read all the information in the instructions for use for a particular drug. Do not panic when you find such an impressive list of possible adverse reactions, because the frequency of their occurrence is low and the treatment is usually well tolerated. If there are contraindications to specific substances, the doctor will be able to choose another remedy with the same mechanism of action, but safe for the patient.

Alpha-beta blockers can be used as drops to treat increased intraocular pressure (glaucoma). The likelihood of a systemic effect is small, but it is still worth keeping in mind some of the possible manifestations of treatment: hypotension and decreased heart rate, bronchospasm, shortness of breath, palpitations and weakness, nausea, allergic reactions. When these symptoms appear, an urgent need to go to an ophthalmologist to correct therapy.

Like any other group of drugs, α, β-adrenergic blockers have contraindications for use, which therapists, cardiologists and other doctors who use them in their practice are aware of.

These funds can not be prescribed to patients with impaired conduction of impulses in the heart. (sinoatrial blockade, AV block 2-3 degrees, sinus bradycardia with a pulse rate of less than 50 per minute), as they will further aggravate the disease. Due to the pressure-lowering effect, these drugs are not used in hypotensive patients, with cardiogenic shock, decompensated heart failure.

Individual intolerance, allergies, severe liver damage, diseases with bronchial obstruction (asthma, obstructive bronchitis) are also an obstacle to the use of adrenergic blocking agents.

Alpha-beta-blockers are not prescribed to expectant mothers and lactating women due to the possible negative effect on the fetus and the body of the nursing baby.

The list of drugs with beta-adrenergic blocking effects is very wide; they are taken by a large number of patients with cardiovascular pathology around the world. With high efficiency, they are usually well tolerated, relatively rarely give side reactions and can be prescribed for a long time.

Like any medication, a beta blocker cannot be taken on its own without medical supervision. even if it helps to reduce blood pressure or eliminate tachycardia in a close relative or neighbor. Before using such drugs, a thorough examination is necessary with the establishment of an accurate diagnosis in order to exclude the risk of adverse reactions and complications, as well as consultation of a therapist, cardiologist, ophthalmologist.