rubefacient vs medicinal drug

rubefacient and medicinal drug both are nouns.

Word	Noun	Adjective	Verb	Adverb
rubefacient	Yes	No	No	No
medicinal drug	Yes	No	No	No

As nouns, medicinal drug is a hypernym of rubefacient; that is, medicinal drug is a word with a broader meaning than rubefacient:

rubefacient: a medicine for external application that produces redness of the skin
medicinal drug: (medicine) something that treats or prevents or alleviates the symptoms of disease

Other hypernyms of rubefacient include medicament, medication, medicine.

rubefacient (noun)	medicinal drug (noun)
a medicine for external application that produces redness of the skin	(medicine) something that treats or prevents or alleviates the symptoms of disease