Beta blockers are a class of drugs that block the action of β-adrenergic receptors. This class includes drugs that block all β-adrenergic receptors in a non-selective manner, and others that can also selectively block one of three types of beta receptors: β 1 , β 2 receptors and β 3 .
The main activity of these substances is to reduce heart rate and blood pressure.
They are mainly used as antiarrhythmic, hypotensive, antianginal and in the treatment of myocardial infarction, cardiac compensation, coronary heart disease, cardiomyopathies and some pathologies of the cardiovascular system.
In sports, β-blockers are used in precision disciplines such as target shooting, archery, pistol shooting, etc. Under these conditions, it is useful to reduce muscle tremors, as this leads to reduced accuracy.
Currently, β-blockers are actually banned in the following sports: aeronautics, motorsport, billiards, bobsleigh, bowling, bowling, curling, gymnastics, wrestling, motorcycling, motorboating, modern pentathlon (for disciplines that include shooting) , skiing, snowboarding, shooting and sailing.
The class of β-blockers includes the following drugs:
Erectile Dysfunction Drugs Among the latest pharmaceutical advances, there are certainly phosphodiesterase type 5 (5PDE) inhibitors used to treat erectile dysfunction. These substances have shown tremendous success in the market, so much so that they have filled the manufacturing industry in the last ten years. Pfaizer, which pioneered this type of drug, Viagra, has become the most important pharmaceutical company in the world thanks to its sales of the aforementioned drug.
the phenomenon of erection This is due to the relaxation of the smooth muscles of the corpora cavernosa of the penis, followed by the expansion of the arteries. The parallel narrowing of the venous vessels causes stagnation of blood, followed by an erection. Relaxation of the smooth muscles of the corpora cavernosa is a nitric oxide (NO) mediated phenomenon. It activates the enzyme guanylate cyclase, which catalyzes the conversion of guanosine triphosphate (GTP) to cyclic guanosine monophosphate (cGMP), which stimulates muscle relaxation. CGMP is cleaved by phosphodiesterazide, which knows at least six isozymes. In the corpora cavernosa, the phosphodiesterase involved is phosphodiesterase type 5 (5PDE).
Erectile dysfunction drugs work by inhibiting 5PDE, causing an increase in blood flow after increasing cGMP concentration, followed by an improvement in erection. In therapeutic doses, these substances do not induce an erection in the absence of sexual stimulation.
The use of these substances can lead to hypotension due to the vasodilating effect , therefore, it can lead to cardiovascular problems In fact, the treatment of erectile dysfunction has been associated with serious cardiovascular events such as heart attack myocardium, intermediate angina pectoris, sudden cardiac death, ventricular arrhythmias, strokes, transient ischemic attack and changes in blood pressure.
Also, sildenafil (the first drug discovered and placed on the market belonging to this class) appears to inhibit beta-adrenergic cardiac stimulation, in fact, while the cardiac effects of sildenafil were minimal at rest, under conditions Beta stimulation or pressure overload Sildenafil reduced dobutamine-induced cardiac reactions and systolic effects after beta stimulation. Among the side effects, we must also remember that there can be disorders such as vomiting, diarrhea, indigestion, hot flashes and, as already mentioned, pressure changes.
Among the molecules mentioned, the progenitor and the first to be Sildenafil ( Viagra ) is sold, after its appearance on the market, two other drugs of the same class were born, namely tadalafil (Cialis) and vardenafil (Levitra) … Of the three compounds, ilViagra is one with the shortest duration of action (6/8 hours) but the most potent, while the others have a much longer lasting activity (Cialis 24 hours) but less intense.
Pulmonary hypertension. This pathology involves severe narrowing of the blood vessels in the lungs, which reduces the ability of the respiratory apparatus to carry oxygen to the body. As a result of the vasodilating action, sildenafil and other substances of this class dilate the artery and other pulmonary vessels, causing a drop in blood pressure in the lungs and increasing the availability of oxygen. Benefits for the user include improved ability to perform aerobic exercise.
Special studies carried out at high altitudes have shown that sildenafil leads to a significant increase in oxygen saturation. in bloody exercise. In addition, the maximum workload and maximum heart capacity have increased. In practice, sildenafil has been shown to significantly improve physical performance in hypoxic conditions at the expense of altitude. In light of this discovery, some athletes use sildenafil to improve aerobic performance in sustained sports. There is still little information about the ability of these substances to influence physical activity, although not all studies have shown real benefits for athletes in endurance skills, the practice of using 5PDE inhibitors before performing in endurance sports is more common. The vasodilating properties of these substances, especially in the lungs, can improve muscle oxygenation capacity, which is why endurance athletes use these products. Sildenafil is usually used rather than other drugs, as it seems to be more effective, the drug is taken one hour before the competition at a dose of 50 mg.
Currently, drugs for the treatment of erectile dysfunction are not included in the list of prohibited substances, however, they may soon be considered drugs that can increase the transport of oxygen, and therefore, their use will be banned.