hydralazine vs vasodilator

hydralazine and vasodilator both are nouns.

Word	Noun	Adjective	Verb	Adverb
hydralazine	Yes	No	No	No
vasodilator	Yes	No	No	No

As nouns, vasodilator is a hypernym of hydralazine; that is, vasodilator is a word with a broader meaning than hydralazine:

hydralazine: an antihypertensive drug (trade name Apresoline) that dilates blood vessels; used (often with a diuretic) to treat hypertension and congestive heart failure
vasodilator: a drug that causes dilation of blood vessels

Other hypernyms of hydralazine include antihypertensive, antihypertensive drug, vasodilative.

hydralazine (noun)	vasodilator (noun)
an antihypertensive drug (trade name Apresoline) that dilates blood vessels; used (often with a diuretic) to treat hypertension and congestive heart failure	a drug that causes dilation of blood vessels