antidiuretic drug vs medication

antidiuretic drug and medication both are nouns.

Word	Noun	Adjective	Verb	Adverb
antidiuretic drug	Yes	No	No	No
medication	Yes	No	No	No

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

antidiuretic drug: a drug that limits the formation of urine
medication: (medicine) something that treats or prevents or alleviates the symptoms of disease

Other hypernyms of antidiuretic drug include medicament, medicinal drug, medicine.

antidiuretic drug (noun)	medication (noun)
a drug that limits the formation of urine	the act of treating with medicines or remedies
	(medicine) something that treats or prevents or alleviates the symptoms of disease