Beta-blockers

Beta-blockers have been used as antihypertensive drugs since the early sixties. Since the discovery of the first results of treatment, and to date, their effectiveness has been convincingly demonstrated in numerous controlled studies, and also when compared with the impact of more modern means.

Beta-blockers are successfully used to reduce blood pressure and prevent the development of cardiovascular disease and mortality. The mechanism of their antihypertensive action is based on a decrease in cardiac output due to a decrease in the force and frequency of contraction. In addition, beta-blockers promote suppression of renin secretion in the juxtaglomerular (near-cell) renal apparatus and, in this connection, the effective suppression of activity in the renin-angiotensin-aldosterone and central vasomotor systems.

Their long-term administration can provoke a reduction in vascular resistance (general peripheral), due to the increased sensitivity of baroreceptors and the production of prostacyclin (vasodilating prostaglandins) in the vascular wall.

Different beta-blockers, used in equivalent doses, have a similar hypotensive effect. Complete antihypertensive treatment develops in two to four weeks. Against the background of a long reception, there may be a "cancellation" syndrome. For its prevention, the drug is not immediately withdrawn, but gradually the dose is reduced for ten to fourteen days.

Systemic effects of drugs, in particular, non-selective, can provoke the development of clinically significant extracardiac and cardiac side effects.

The first group includes disorders on the psychoemotional background (depression, sleep disturbance, etc.), respiratory manifestations (bronchospasm), peripheral vasoconstriction (intermittent claudication, cold extremities, etc.), weakness in muscles, impotence. Extracardial side effects are impaired renal function, caused by a decrease in blood flow in the kidneys, difficulties in lipid and carbohydrate metabolism.

The group of cardiac manifestations includes:

• Impaired pumping heart function, accompanied with symptoms of insufficiency;
• Blockade (atrioventricular, sinoatrial) of the heart and bradycardia;
• Development of hypotension against the background of excessive blood pressure lowering;
• Antiarrhythmic effect.

It should be noted that the diversity in the pharmacological properties of blockers makes it possible to select the optimal drug for almost every case. This also takes into account the tolerability of treatment, the least risk of side effects, the duration of exposure and the type of clinical situation.

The appointment of beta-blockers as a single therapy allows achieving normalization of blood pressure in the order of 40-50% of patients with arterial hypertension. In comparison with the impact on patients in young, middle and older age, the effect is relatively lower in the elderly. The use of a thiazide diuretic in combination with a beta-blocker can eliminate differences. Thus, the effectiveness of therapy with this combination increases to 78-80%.

Beta-adrenoblockers for the treatment of angina pectoris occupy a separate place. With this disease, such drugs as Anaprilin (Obsidan), Sotalol, Atenolol, Concor, Monotard are used.

The action of all these medicines is aimed at lowering blood pressure and "slowing down" the heart rate. Dosage of any drug should be selected strictly by the individual physician.

Contraindications for bronchial asthma, chronic obstructive pulmonary diseases, atrioventricular blockade of the second to third degrees. It is not recommended to use beta-blockers in violation of glucose tolerance, diseases of peripheral arteries, athletes and physically active persons.