Metoprolol, Carvedilol, Propranolol (Efficacy)
Regulation of the nervous system is carried out by means of substances called catecholamines (adrenaline and noradrenaline). To exert their action, these substances have to bind to receptors located on the surface of cells, called adrenergic receptors. One of these receptors is the so-called β-adrenergic receptor, which is found primarily in the heart, arteries and lungs. When this receptor is stimulated with the arrival of catecholamine, the heart rate, blood pressure and cardiac contractility are increased. A β-blocker is a drug that blocks the β-adrenergic receptor, in such a way that it prevents the union of the catecholamine and prevents its stimulation. The final effect is a reduction in heart rate, blood pressure and contractility (strength of the heart) by favoring cardiac diastole (filling) and thereby improving heart function and blood flow to the coronary arteries.
The indications for which β-blockers are prescribed are the following: Angina Pectoris (β-blockers reduce the oxygen needs of the heart by reducing the heart rate, blood pressure and the force exerted by the heart, increase blood flow to coronary arteries, so they reduce the symptoms of angina, prevent cardiac remodeling and produce an improvement in ventricular function), Prevention of new heart attacks (In people who have had a myocardial infarction, beta-blockers are able to reduce the risk of having a new heart attack or die due to cardiac causes), Arrhythmias, Heart failure (When the heart has lost strength, beta-blockers can improve this situation in addition to reducing the risk of death, hospitalization rates and relieve the symptoms of heart failure), Hypertrophic cardiomyopathy (Hypertrophic cardiomyopathy is a disease of the cardiac muscle in which we find it very thickened, this does not allow an adequate filling of the heart cavities. Beta-blockers can improve ventricular function and alleviate the symptoms of this disease by decreasing the heart rate) and Arterial hypertension (β-blockers reduce blood pressure and can be used alone or in combination with other drugs).
In addition to cardiac indications, β-blockers are also used to treat Glaucoma (increased intraocular pressure), Anxiety, Hyperthyroidism and Migraine.
In general, β-blockers are not used in people with asthma because that medications can trigger severe asthma attacks. In people who have diabetes, β-blockers can hide the signs of a low blood sugar level, such as a fast heartbeat. It is important to check the blood sugar level regularly in this type of patients.
Beta-blockers can also affect cholesterol and triglyceride levels, and cause a slight increase in the latter and a modest decrease in high-density lipoproteins, the so-called ""good"" cholesterol. These changes are often temporary.
The intake of beta-blockers should not be stopped abruptly, since doing so could increase the risk of having a heart attack or having other heart problems.
- Dizziness sensation or instability
- Exhaustion or fatigue sensation
- Asthma (asthmatics should inform their doctor before starting treatment as it could provoke bronchospasm attacks.
- Erectile dysfunction
- Legs and hands coldness
- Mood disorders
- Lopressor®, Toprol-XL® (Metoprolol)
- Inderal LA®, InnoPran XL® (Propranolol)
- Coropres ®, Normotride ®, Palacimol ® (Carvedilol)
- Zebeta® (Bisoprolol)
- Sectral® (Acebutolol)
- Tenormin® (Atenolol)
Gene or region studied