antispasmodic vs antispasmodic agent

antispasmodic and antispasmodic agent both are nouns.

Word	Noun	Adjective	Verb	Adverb
antispasmodic	Yes	No	No	No
antispasmodic agent	Yes	No	No	No

As nouns, antispasmodic and antispasmodic agent are synonyms defined as:

antispasmodic and antispasmodic agent: a drug used to relieve or prevent spasms (especially of the smooth muscles)

Other synonyms of antispasmodic include spasmolytic.

antispasmodic (noun)	antispasmodic agent (noun)
a drug used to relieve or prevent spasms (especially of the smooth muscles)	a drug used to relieve or prevent spasms (especially of the smooth muscles)