m-, n-Cholinomimetics, including anticholinesterase drugs
Stimulating effect on cholinergic transmission have acetylcholine chloride, carbachol — the so-called direct holinomimetiki. They directly interact with the m - and n-cholinergic receptors. More often, however, for this purpose, use anticholinesterase drugs (physostigmine, galantamine, neostigmine, methylsulfate, pyridostigmine bromide, aminostigmin, rivastigmine, ipidacrine, etc.). They inhibit the cholinesterase — enzyme that destroys endogenous acetylcholine, cause accumulation of acetylcholine in cholinergic nerve endings and enhance its effect on the organs and tissues. Therefore, the effects of anticholinesterases are largely similar to those of acetylcholine.
Depending on the chemical structure and physicochemical properties of different drugs in this group differ from each other. Tertiary amines (fizostigmin, galantamin, etc.) penetrate biological membranes, including the GEB, and have an activating effect on the CNS. For Quaternary ammonium derivatives (metilsulfate neostigmine, pyridostigmine bromide, amrinone chloride, etc.) GAB impassable, so they have an impact mostly on the peripheral cholinergic system. There are substances (Armin, paraoxon) irreversible (covalent) binding of cholinesterase. They are highly active but also very toxic, which limits their clinical application.