الفهرس 
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Abstract
Anticholinergic drugr inhibit the action of acetyl— choline on structures innervated by postganglionic parasy pathetic nerves. These drugs do not prevent acetyl— choline from being released at nerve endings, but they may cetnpete with the liberated neurohormone for cholinergic receptor sites.
The classical parasympatholytic agent is atropine,
and therefore anticholinergics used to be referred to as
atropinic agents. Substances patterned on atropine are
:wide13T used as antissmodics of the gastrointestinal tract. Theoretically any substance,that relaxes the acetyicholine— induced spasm of the smooth muscles in suitable doses, can be termed an antispasmodic. In practice not every anti— cholinergic agent can be used as an antispa&oodic. The reason is that, in addition to their spasmolytic action, anticholinergics influence the functions of other organs; including heart, sweat and salivary glands, and iritic and ciliary tnuscles;producing side effects.
tThe ideal atropine—like antispasnodic should be specific for the spasmogen, chould have selectivity for swooth muscle, and should abolish conpletely the spasm induced by the stiDulation of the parasympatheic nerve to the organ. None of the available antispasmodics satisfies all of these requirenents. riowever, nany compounds have been syntnesised with the hope of developing