DDI vs ddI

DDI and ddI both are nouns.

Word	Noun	Adjective	Verb	Adverb
DDI	Yes	No	No	No
ddI	Yes	No	No	No

As nouns, DDI and ddI are synonyms defined as:

DDI and ddI: an antiviral drug used to combat HIV infection, a reverse transcriptase inhibitor

Other synonyms of DDI include didanosine, dideoxyinosine.

DDI (noun)	ddI (noun)
an antiviral drug used to combat HIV infection, a reverse transcriptase inhibitor	an antiviral drug used to combat HIV infection, a reverse transcriptase inhibitor