sedative vs medicinal drug

sedative and medicinal drug both are nouns.

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

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

sedative: a drug that reduces excitability and calms a person
medicinal drug: (medicine) something that treats or prevents or alleviates the symptoms of disease

Other hypernyms of sedative include drug of abuse, street drug, medicament, medication, medicine.

sedative (noun)	medicinal drug (noun)
a drug that reduces excitability and calms a person	(medicine) something that treats or prevents or alleviates the symptoms of disease

sedative (adjective)	medicinal drug (adjective)
tending to soothe or tranquilize