doxycycline vs antibiotic drug

doxycycline and antibiotic drug both are nouns.

Word	Noun	Adjective	Verb	Adverb
doxycycline	Yes	No	No	No
antibiotic drug	Yes	No	No	No

As nouns, antibiotic drug is a hypernym of doxycycline; that is, antibiotic drug is a word with a broader meaning than doxycycline:

doxycycline: an antibiotic derived from tetracycline that is effective against many infections
antibiotic drug: a chemical substance derivable from a mold or bacterium that can kill microorganisms and cure bacterial infections

Other hypernyms of doxycycline include antibiotic.

doxycycline (noun)	antibiotic drug (noun)
an antibiotic derived from tetracycline that is effective against many infections	a chemical substance derivable from a mold or bacterium that can kill microorganisms and cure bacterial infections