Adrenolytics or antiadrenergic drugs lower the tone of the sympathetic part of the autonomic nervous system. Given the mechanism of action, they are divided into adrenergic blockers (non-selective and selective – depending on the selectivity of action on the types and subtypes of adrenergic receptors) and sympatholytic.
Adrenergic blockers shield (close) adrenergic receptors and prevent norepinephrine from interacting with them, respectively, causing effects opposite to those that develop as a result of exposure to adrenergic drugs. The blockade of postsynaptic alpha1 receptors of blood vessels contributes to their expansion, beta1 receptors of the heart – weakening and shortening of heart contractions, a decrease in automatism and slowing down of AV conduction, beta2 receptors – narrowing of small vessels and an increase in bronchial tone.
Alpha-blockers are mainly prescribed for hypertensive conditions and diseases associated with peripheral vasoconstriction; beta-blockers are used as antiarrhythmic, antianginal and antihypertensive drugs.