Carbamoyl esters inhibit cholinesterase activity and, upon hydrolysis release a pharmacologically active agent. In one embodiment, the carbamoyl ester has the following structure: Formula (I) wherein A is selected from the group consisting of an unsubstituted aryl, a substituted aryl, an unsubstituted heteroaryl and a substituted heteroaryl. The carbamoyl esters are employed in methods to treat an individual. The pharmacologically active agent obtained by hydrolysis of the carbamoyl esters can treat, for example, a nervous system condition, a cholinergic deficiency and conditions or diseases associated with a deficiency in a pharmacologically active agent, such as acetylcholine.