Autonomic Ocular Drugs: Desirable and Undesirable Effects.

A,.t the present time most pharmacologists believe that acetylcholine is the activator and propagator of the chemical change present in all nerve conduction. This involves the axon and all synaptic junctions of both the sympathetic and the parasympathetic systems. At the sympathetic end organs, sympathin or norepinephrine is released as the effecter substance. Acetylcholine itself is the parasympathetic effecter substance. In ocular therapy it is possible to augment the action of the autonomic system by drugs having the same action on the end organ as does acetylcholine or sympathin. Other drugs augment autonomic action by interfering with the enzymes cholinesterase and methyl transferase which are responsible for the destruction of acetylcholine or sympathin, respectively. These sites of action provide a convenient method of classifying autonomic drugs. Only those most commonly used will be discussed.