ATC Group: S01EB Parasympathomimetics

Aceclidine is a cholinergic muscarinic agonist that stimulates muscarinic receptors located on smooth muscles. Aceclidine is a predominately pupil selective miotic that interacts with the iris with minimal ciliary muscle stimulation. Aceclidine causes contraction of the iris sphincter muscle, resulting in a pinhole effect that extends depth of focus to improve vision.

Acetylcholine is a physiological neuromediator of postganglionic parasympathetic nerve fibres (muscarinic action), skeletal muscles and ganglia of the sympathetic system (nicotinic action).

Carbachol is a potent cholinergic (parasympathomimetic) agent which produces constriction of the iris and ciliary body resulting in reduction in intraocular pressure (IOP).

Neostigmine inhibits cholinesterase activity and prolongs and intensifies the muscarinic and nicotinic effects of acetylcholine. The anticholinesterase actions of neostigmine are reversible. It is used mainly for its action on skeletal muscle and less frequently to increase the activity of smooth muscle.

Physostigmine is a reversible inhibitor of acetylcholinesterase. As an inhibitor of acetyl-cholinesterase, physostigmine slows down the degradation of acetylcholine and acts like an indirect parasympathomimetic drug due to an increase of the acetylcholine concentration at the receptor.

Pilocarpine is a cholinergic parasympathomimetic agent exerting a broad spectrum of pharmacologic effects with predominant muscarinic action. Pilocarpine, in appropriate dosage, can increase secretion by exocrine glands such as the sweat, salivary, lacrimal, gastric, pancreatic and intestinal glands and the mucous cells of the respiratory tract.