immunosuppressor vs immune suppressant drug

immunosuppressor and immune suppressant drug both are nouns.

Word	Noun	Adjective	Verb	Adverb
immunosuppressor	Yes	No	No	No
immune suppressant drug	Yes	No	No	No

As nouns, immunosuppressor and immune suppressant drug are synonyms defined as:

immunosuppressor and immune suppressant drug: a drug that lowers the body's normal immune response

Other synonyms of immunosuppressor include immunosuppressant, immunosuppressive, immunosuppressive drug.

immunosuppressor (noun)	immune suppressant drug (noun)
a drug that lowers the body's normal immune response	a drug that lowers the body's normal immune response