cimetidine vs gastric antacid

cimetidine and gastric antacid both are nouns.

Word	Noun	Adjective	Verb	Adverb
cimetidine	Yes	No	No	No
gastric antacid	Yes	No	No	No

As nouns, gastric antacid is a hypernym of cimetidine; that is, gastric antacid is a word with a broader meaning than cimetidine:

cimetidine: a drug (trade name Tagamet) used to treat peptic ulcers by decreasing the secretion of stomach acid
gastric antacid: an agent that counteracts or neutralizes acidity (especially in the stomach)

Other hypernyms of cimetidine include histamine blocker, alkaliser, alkalizer, antacid, antiacid.

cimetidine (noun)	gastric antacid (noun)
a drug (trade name Tagamet) used to treat peptic ulcers by decreasing the secretion of stomach acid	an agent that counteracts or neutralizes acidity (especially in the stomach)