immunosuppressive drug vs immunosuppressor

immunosuppressive drug and immunosuppressor both are nouns.

Word	Noun	Adjective	Verb	Adverb
immunosuppressive drug	Yes	No	No	No
immunosuppressor	Yes	No	No	No

As nouns, immunosuppressive drug and immunosuppressor are synonyms defined as:

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

Other synonyms of immunosuppressive drug include immune suppressant drug, immunosuppressant, immunosuppressive.

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