dope vs dope up

dope is a noun but dope up is not a noun.

Word	Noun	Adjective	Verb	Adverb
dope	Yes	No	Yes	No
dope up	No	No	Yes	No

As verbs, dope and dope up are synonyms defined as:

dope (noun)	dope up (noun)
street names for marijuana
slang terms for inside information
carbonated drink flavored with extract from kola nuts
an ignorant or foolish person

dope (verb)	dope up (verb)
give a narcotic to	give a narcotic to
add impurities to (a semiconductor) in order to produce or modify its properties
take drugs to improve one's athletic performance