neuroleptic agent vs major tranquilizer

neuroleptic agent and major tranquilizer both are nouns.

Word	Noun	Adjective	Verb	Adverb
neuroleptic agent	Yes	No	No	No
major tranquilizer	Yes	No	No	No

As nouns, neuroleptic agent and major tranquilizer are synonyms defined as:

neuroleptic agent and major tranquilizer: tranquilizer used to treat psychotic conditions when a calming effect is desired

neuroleptic agent (noun)	major tranquilizer (noun)
tranquilizer used to treat psychotic conditions when a calming effect is desired	tranquilizer used to treat psychotic conditions when a calming effect is desired