Binding to postsynaptic alphaone-adrenergic receptors of the vascular wall, they (phenylephrine, etc.) cause contraction of smooth muscles, vasoconstriction and an increase in blood pressure. This group also includes clonidine, guanfacine, methyldopa, etc. Penetrating through the BBB, they stimulate presynaptic alpha2-adrenergic receptors of the vasomotor center of the brain, reduce the release of a mediator into the synaptic cleft and reduce the flow of sympathetic impulses from the central nervous system, which leads to a decrease in blood pressure. Another alpha effectone-adrenergic agonists (indanazoline, xylometazoline, naphazoline, etc.) is a decrease in secretion in the nasal cavity and facilitation of nasal breathing.
Below is a list of alpha-adrenergic agonists:
- Naphazoline * + Pheniramine