hrvatski

Neizravni parasimpatomimetici

Indirect parasympathomimetics or anticholinesterase drugs are antagonists of the enzyme acetylcholinesterase, the enzyme which hydrolyses acetylcholine. The effect of anticholinesterases is increased level of the natural neurotransmitter and increased cholinergic activity. They are used in treatment of glaucoma, myasthenia gravis, intestinal and bladder atony, and as antidotes of anticholinergic agents and stabilizing muscle relaxants. There are two groups of anticholinesterase drugs - carbamates and organophosphorus agents. The mechanism of action for both types of compounds is similar. The esteratic center of acetylcholinesterase reacts with the carbaminic acid or phosphoric acid esters and inhibits the hydrolysis of released acetylcholine. Whereas the regeneration of the enzyme is rapid for carbamic acid derivatives, the phosphorylated enzyme is hydrolyzed very slow. So the first derivatives are called reversible, and the second irreversible acetylcholinesterase blockers. The most important carbamic acid derivatives are physostigmine, neostigmine, pyridostigmine, distigmine. Only two organophosphorus derivatives are in use as drugs: dyflos and ecothiopate. The other compounds are nerve poisonous gases (sarin) or insecticides (parathion and malathion).

neizravni parasimpatomimetici; inhibitori antikolinesteraze; fizostigmin; organoforsforni spojevi

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