antihypertensive vs medication

antihypertensive and medication both are nouns.

Word	Noun	Adjective	Verb	Adverb
antihypertensive	Yes	No	No	No
medication	Yes	No	No	No

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

antihypertensive: a drug that reduces high blood pressure
medication: (medicine) something that treats or prevents or alleviates the symptoms of disease

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

antihypertensive (noun)	medication (noun)
a drug that reduces high blood pressure	the act of treating with medicines or remedies
	(medicine) something that treats or prevents or alleviates the symptoms of disease