anti-impotence drug vs drug

anti-impotence drug and drug both are nouns.

Word	Noun	Adjective	Verb	Adverb
anti-impotence drug	Yes	No	No	No
drug	Yes	No	Yes	No

As nouns, drug is a hypernym of anti-impotence drug; that is, drug is a word with a broader meaning than anti-impotence drug:

anti-impotence drug: drug to treat impotence attributable to erectile dysfunction
drug: a substance that is used as a medicine or narcotic

anti-impotence drug (noun)	drug (noun)
drug to treat impotence attributable to erectile dysfunction	a substance that is used as a medicine or narcotic

anti-impotence drug (verb)	drug (verb)
	administer a drug to
	use recreational drugs