antimalarial drug vs antimalarial

antimalarial drug and antimalarial both are nouns.

Word	Noun	Adjective	Verb	Adverb
antimalarial drug	Yes	No	No	No
antimalarial	Yes	No	No	No

As nouns, antimalarial drug and antimalarial are synonyms defined as:

antimalarial drug and antimalarial: a medicinal drug used to prevent or treat malaria

antimalarial drug (noun)	antimalarial (noun)
a medicinal drug used to prevent or treat malaria	a medicinal drug used to prevent or treat malaria