Acetylcholine Chloride is the chloride salt form of acetylcholine, a synthetic, quaternary amino alcohol with cholinergic properties. Acetylcholine chloride mimics the parasympathomimetic effect of the endogenous compound acetylcholine. Administered as an ophthalmic solution, this drug stimulates the cholinoceptors in the sphincter muscle of the iris, causing the pupil to constrict.