From this article you will learn: the action of bisoprolol on the body, from which bisoprolol is used.
The effects of bisoprolol
Bisoprolol is a drug from the group of beta-blockers -blocking the effect of adenaline and norepinephrine on tissues and organs.
Bisoprolol lowers blood pressure, reduces heart rate( heart rate), prevents the development of tachyarrhythmias, reduces cardiac output, reducing the burden on the heart.
Due to a wide range of effects on the structure and function of the heart, the drug is prescribed for the treatment of many cardiological diseases: coronary heart disease( CHD), certain types of arrhythmias, chronic heart failure( CHF), arterial hypertension.
Structural formula of bisoprolol Effects of bisoprolol
Adrenaline and norepinephrine have an effect on the body, acting on different types of receptors. Beta-1-adrenergic receptors predominate in the heart and some other organs. Beta-2-adrenergic receptors are located in the bronchi, vascular wall, in the digestive tract, adipose tissue, pancreas. Bisoprolol is a selective beta-blocker, since it blocks predominantly beta-1-adrenergic receptors. The absence of the effect of the drug on the second type of receptor allows avoiding many side effects and widening the range of application of the drug.
Interaction with beta-1 adrenoceptors of adrenaline and norepinephrine( catecholamines) can aggravate the state of health in the presence of cardiopathology. The intake of bisoprolol reduces the toxic effect of catecholamines, reduces the severity of symptoms, slows the progression of cardiac pathology.
| Interaction of epinephrine and norepinephrine with receptors | Effects of bisoprolol |
|---|---|
| Heart rate acceleration | Deceleration of the rhythm |
| Strengthening of myocardial contractions | Reduction of contraction force |
| Increase of the automatism of the rhythm drivers( spontaneous creation of pulses leading to rhythmic contraction of the heart), myocardial excitability( the ability of myocardial cells to react with contractionon incoming impulses) | Decrease in automatism and excitability |
| Acceleration of conduction in atrioventricular soybean | The slowing down, shortening of the QT interval( parameter on the electrocardiogram, prolongation of which leads to an increased risk of severe arrhythmias) |
Beta-1-adrenergic receptors are found in various organs, which leads to a variety of bisoprolol influences on the functioning of the organism, including the limitations of the drug usewith some diseases.
| Organs and tissues containing beta 1-adrenergic receptors | Effects of blockade of | receptors Indications for treatment with bisoprolol | Features of appointment, limitations, contraindications |
|---|---|---|---|
| Cardiac muscle - myocardium | Decrease in the contraction and pressure in the left ventricle of the heart during the relaxation phase, reducing the need foroxygen | Chronic heart failure( CHF), ischemic heart disease( CAD) | Contraindicated in acute heart failure and decompensation of CHF, with shock |
| ConductingSingle system | heart rate Decrease of heart rate, excitability, atrioventricular conduction | tachyarrhythmia beats | not used in heart rate below 50 per minute, with sick sinus syndrome, sinoatrial or atrioventricular block 2-3 tbsp. |
| Renal Yuxtaglomerular apparatus | Reduction of renin release leading to lowering blood pressure | Hypertension | Contraindicated in severe hypotension( systolic blood pressure 100 mmHg or less) |
| Eyes | Decreased intraocular fluid production | Use with caution combination with local blockers fortreatment of glaucoma | |
| System of portal vein | Pressure reduction | Positive effect with portal hypertension | |
| Central | Inhibitory effect in the form of suppression of sympathetic impulses, drowsiness, depression, insomnia | Precautions for use in depression, can not be combined with MAO inhibitors |
Bisoprolol blocks beta 1-adrenergic receptors, limiting the possibility of interaction with adrenergic substances. With the ability to weaken the influence of norepinephrine and adrenaline on the activity of the heart, therapeutic effects of the drug are associated.
Effects of beta-blockers. Click on photo to enlarge Action of bisoprolol in ischemic heart disease
In CHD, there is a mismatch between the needs of the heart muscle in oxygen and its intake of blood through the coronary artery network. Bisoprolol does not change the amount of oxygen delivered, but it reduces the load on the heart and its need for blood supply. This is realized due to the following mechanisms:
- Bisoprolol reduces heart rate and duration of heart muscle relaxation period. The flow of blood to the cells occurs mainly during this period, because when the heart is contracted, the coronary arteries in the myocardium are pinched.
- Reducing contractile force and blood pressure reduces the need for cardiomyocytes in oxygen.
- Under the influence of medicine, the pressure in the left ventricle of the heart in the period between contractions decreases, which leads to an improvement in the blood supply of the myocardium.
- Blockade of toxic effects of high concentrations of catecholamines.
The consequence of IHD is myocardial infarction, in which cardiac muscle necrosis occurs due to lack of oxygen The use of bisoprolol in IHD can reduce the burden on the heart and reduce the risk of coronary complications. The drug provides the following positive changes in the patients' condition:
- reduces the incidence of angina attacks;
- improves load tolerance;
- prevents the development of arrhythmias or has a therapeutic effect with existing tachycardia or extrasystolic arrhythmia;
- reduces the likelihood of complications - myocardial infarction, sudden coronary death;
- slows the progression of chronic heart failure.
Bisoprolol in the treatment of heart failure
Reducing the strength of the heartbeat, it would seem, should enhance the manifestations of heart failure, in which the functional capacity of the myocardium is reduced. Indeed, bisoprolol is contraindicated in acute heart failure or decompensation of the condition - in such a situation, taking the drug can have fatal consequences.
But with chronic insufficiency( abbreviated CHF), bisoprolol can significantly improve the function of the heart. Begin receiving the drug with minimal doses, gradually increasing to the target. The treatment process is controlled by a cardiologist or therapist.
The mechanism of action of this beta-blocker in CHF:
- Decreased heart rate and improved left ventricular function.
- Braking and reverse development of pathological cardiac remodeling( hypertrophy and expansion of cavities).
- Improvement of pumping function of the heart with prolonged medication.
- Blocking of toxic effects of adrenergic substances and inhibition of cardiac cell death.
- Reducing the electrical instability of the myocardium and reducing the risk of arrhythmias.
- Blocking renin release in the kidney and suppressing the activity of the renin-angiotensin-aldosterone system, which has a significant effect on the progression of heart failure.
Bisoprolol helps to eliminate or reduce the following symptoms:
- heart palpitations;
- physical activity limitation;
- shortness of breath;
- probability and frequency of occurrence of arrhythmias.
Drug administration slows the progression of CHF, improves prognosis, quality of life of patients.
Bisoprolol has a higher degree of beta1 selectivity than other beta1-selective beta-blockers( such as atenolol, metoprolol and betaxolol) Effectiveness of the drug at elevated pressure
The pressure-lowering effect of bisoprolol is mainly due to the following mechanisms:
- reduction in cardiac output;
- by blocking the release of renin - an enzyme that triggers a cascade of reactions leading to increased pressure;
- suppression of impulses from the central part of the sympathetic nervous system, leading to a decrease in stimulation of cardiac activity and a decrease in pressure.
Treatment with bisoprolol helps to eliminate the following symptoms:
- to lower blood pressure;
- to reduce the severity of symptoms associated with high blood pressure - headache, nausea, increased fatigue and others.
The choice of bisoprolol as an antihypertensive agent is preferred in the presence of tachycardia, heart failure, IHD, factors of increased cardiovascular risk, the threat of arrhythmia.
Application of bisoprolol in cardiac arrhythmias
Cardiac activity is impossible without automatic functions and impulses. In cardiac diseases these functions can be violated, which makes it necessary to perform antiarrhythmic therapy. Antiarrhythmic action of bisoprolol is associated with several mechanisms:
- by lowering heart rate;
- by delayed conduction in the atrioventricular junction;
- decrease in the probability of occurrence of impulses in ectopic foci, and hence the risk of developing extrasystole and tachyarrhythmias.
Ectopic arrhythmia is a kind of arrhythmia in which additional ectopic foci of increased excitability arise in the cardiac muscle, capable of generating impulses that cause an extraordinary contraction of the heart( extrasystoles).This is a large peak in the photo of the ECG The likelihood of arrhythmias when taking the drug is also reduced due to anti-ischemic action, improvement of metabolic processes in the myocardium, suppression of sympathetic impulses from the central nervous system.
The appointment of bisoprolol is indicated in such types of arrhythmias:
- sinus tachycardia,
- ventricular extrasystole,
- supraventricular tachycardia,
- fibrillation, atrial flutter,
- syndrome elongated QT.
Bisoprolol is especially indicated as a means for arrhythmia in the treatment of IHD and CHF.
Who appoints bisoprolol
Uncontrolled use of the drug can lead to serious health problems. Only a doctor should decide what bisoprolol should be used for. The therapist or cardiologist is sent to the necessary examination, determine the indications, exclude contraindications and select an individual dosage of the drug. In many cases, start with a minimal dose of bisoprolol, slowly increasing it to a level that provides the maximum therapeutic effect and is well tolerated by the patient.
Beta-blockers are often used in the treatment of heart disease, but their use can be limited by existing contraindications, individual intolerance, undesirable combination with individual drugs.
Despite the selectivity of bisoprolol, large doses of the drug may lead to blockade of beta-2-adrenergic receptors with the appearance of undesirable effects, in particular, bronchospasm, peripheral circulation disorders. Therefore, the prescribed drug should be taken under the supervision of a doctor who, if necessary, will adjust the dose of bisoprolol or cancel the drug. Stop taking the drug with caution, gradually lowering the dose due to the possibility of withdrawal syndrome.
