prescription drug vs ethical drug

prescription drug and ethical drug both are nouns.

Word	Noun	Adjective	Verb	Adverb
prescription drug	Yes	No	No	No
ethical drug	Yes	No	No	No

As nouns, prescription drug and ethical drug are synonyms defined as:

prescription drug and ethical drug: a drug that is available only with written instructions from a doctor or dentist to a pharmacist

Other synonyms of prescription drug include prescription, prescription medicine.

prescription drug (noun)	ethical drug (noun)
a drug that is available only with written instructions from a doctor or dentist to a pharmacist	a drug that is available only with written instructions from a doctor or dentist to a pharmacist