gastric antacid vs alkaliser

gastric antacid and alkaliser both are nouns.

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

As nouns, gastric antacid and alkaliser are synonyms defined as:

gastric antacid and alkaliser: an agent that counteracts or neutralizes acidity (especially in the stomach)

Other synonyms of gastric antacid include alkalizer, antacid, antiacid.

gastric antacid (noun)	alkaliser (noun)
an agent that counteracts or neutralizes acidity (especially in the stomach)	an agent that counteracts or neutralizes acidity (especially in the stomach)