This group includes adrenomimetics that excite only beta-adrenergic receptors. Among them, there are non-selective beta1-, beta2-adrenergic agonists (isoprenaline, orciprenaline) and selective: beta1-adrenergic agonists (dobutamine) and beta2-adrenergic agonists (salbutamol, fenoterol, terbutaline, etc.). As a result of the excitation of beta-adrenergic receptors, membrane adenylate cyclase is activated and the level of intracellular calcium increases. Non-selective beta-agonists increase the strength and heart rate, while relaxing the smooth muscles of the bronchi. The development of unwanted tachycardia limits their use in relieving bronchospasm. On the contrary, selective beta2-adrenomimetics are widely used in the treatment of bronchial asthma and chronic obstructive pulmonary diseases (chronic bronchitis, emphysema, etc.), since they have fewer side effects (on the heart). Beta2-adrenergic agonists are prescribed both parenterally and orally, however, inhalation is most effective.
Selective beta1-adrenergic agonists to a greater extent have an effect on the heart muscle, causing a positive foreign, chrono- and batmotropic effect, and less pronounced decrease in TPR. They are used as adjuvants in acute and chronic heart failure.
Below is a list of beta-agonists:
- Dobutamine hydrochloride (Dobutaminum hydrochloridum)