immunosuppressive drug vs immune suppressant drug

immunosuppressive drug and immune suppressant drug both are nouns.

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

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

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

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

immunosuppressive drug (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