How is Echothiophate (Phospholine Iodide) as irreversible anticholinesterase?

Organophosphate covalently binds via phosphate group to serine-OH group at active site of acetylcholinesterase. Permenantly inactivates acetylcholinesterase, and its activity requires synthesis of new molecules, following the covalent modification, the enzyme slowly releases one of its ethyl groups, which is called aging, make it possible for chemical reactivators such as Pralidoxime (PAM) to break this bond. Actions (generalized cholinergic stimulation, paralysis of motor function causing breathing difficulty, convulsions) Atropine in high dosage can reverse many of muscarinic and central effects of it. Used as ophthalmic solution to treat chronic open angel glaucoma. Effect lasts up to one week, not first-lline glaucoma treatment, may be topical use