As nouns the difference between drug and bifeprunox
is that
drug is (pharmacology) a substance used to treat an illness, relieve a symptom, or modify a chemical process in the body for a specific purpose or
drug can be (obsolete) a drudge while
bifeprunox is an antipsychotic drug.
As a verb drug
is to administer intoxicating drugs to, generally without the recipient's knowledge or consent or
drug can be (
drag).