demecarium

noun

dem·​e·​car·​i·​um ˌdem-i-ˈkar-ē-əm, -ˈker- 

: a long-acting cholinesterase-inhibiting quaternary ammonium compound that is a derivative of neostigmine and is used as the bromide C₃₂H₅₂Br₂N₄O₄ in an ophthalmic solution especially in the treatment of glaucoma and esotropia