Atropine is a tropane alkaloid extracted from the deadly nightshade (Atropa belladonna) and other plants of the family Solanaceae. It is a secondary metabolite of these plants and serves as a drug with a wide variety of effects. It is a competitive antagonist for the muscarinic acetylcholine receptor. Being potentially deadly, it derives its name from Atropos, one of the three Fates who, according to Greek mythology, chose how a person was to die.
Physiological effects and uses
Generally, atropine lowers the "rest and digest" activity of all muscles and glands regulated by the parasympathetic nervous system. This occurs because atropine is a competitive antagonist of the muscarinic acetylcholine receptors. (Acetylcholine is the main neurotransmitter used by the parasympathetic nervous system.) Therefore, it may cause swallowing difficulties and reduced secretions.
Topical atropine is used as a cycloplegic, to temporarily paralyze the accommodation reflex; and as