Carbaminoylcholine is one of a group of synthetic choline derivatives which act principally by parasympathetic stimulation. In chemical structure (chart 1) it is similar to acetylcholine, but its action is more prolonged, since it is stable in the tissues and hydrolysis is slow.
The initial experiments on the ocular effects of carbaminoylcholine chloride were made on isolated iris sphincter and indicated that this drug may be the most powerful of all known miotics.1 However, clinical reports have been conflicting. Guyton2 in a recent review of the líterature found no unanimity of opinion regarding the degree and the duration of miosis but concluded that the miosis is probably greater but less prolonged than that produced by similar concentrations of pilocarpine. Velhagen3 found the effect of a 0.75 per cent concentration of carbaminoylcholine chloride on the accommodation of the normal human eye to be less than that of a