Name: Echothiophate (Phospholine)
Class: Anticholinesterase Agent: Organophosphate
Mech.: Binds irreversibly to AChE
Absorption: Eye drops.
Dist.:
Metab.:
Excretion, t½: Long-lasting inhibition—days to weeks.
Toxicity/S.E.s: Toxic doses first stim. then depress autonomic ganglia, neuromusc. jxns, and central sites. Treat w/heroic doses of atropine for muscarinic effects, pralidoxine for neuromusc effects.
Utility: Topical eye applic. to treat glaucoma. For closed-angle glaucoma, stim. constriction of iris sphincter ® iris removed from entrance to trabecular space. For open-angle glaucoma, stim. sphincter and ciliary body contraction ® patency of trabecular network. Topical to treat crossed eyes.
Special Features: Bond btwn drug and AChE must age before becoming irreversible. While bond is aging, drugs such as pralidoxime can reactivate AChE.