omeprazole vs gastric antacid

omeprazole and gastric antacid both are nouns.

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

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

omeprazole: antacid (trade name Prilosec) that suppresses acid secretion in the stomach
gastric antacid: an agent that counteracts or neutralizes acidity (especially in the stomach)

Other hypernyms of omeprazole include alkaliser, alkalizer, antacid, antiacid.

omeprazole (noun)	gastric antacid (noun)
antacid (trade name Prilosec) that suppresses acid secretion in the stomach	an agent that counteracts or neutralizes acidity (especially in the stomach)