ddI vs antiviral agent

ddI and antiviral agent both are nouns.

Word	Noun	Adjective	Verb	Adverb
ddI	Yes	No	No	No
antiviral agent	Yes	No	No	No

As nouns, antiviral agent is a hypernym of ddI; that is, antiviral agent is a word with a broader meaning than ddI:

ddI: an antiviral drug used to combat HIV infection, a reverse transcriptase inhibitor
antiviral agent: any drug that destroys viruses

Other hypernyms of ddI include antiviral, antiviral drug.

ddI (noun)	antiviral agent (noun)
an antiviral drug used to combat HIV infection, a reverse transcriptase inhibitor	any drug that destroys viruses