 By giving this medication it becomes easier to do "dry" dentistry.Propantheline is one of a group of antispasmodic medications which work by blocking the action of the chemical messenger acetylcholine, which is produced by nerve cells, to muscarinic receptors present in various smooth muscular tissues, in places such as the gut, bladder and eye.Normally, the binding of acetylcholine induces involuntary smooth muscular contractions.