ddI (didanosine, Videx / VidexEC) is an anti-HIV drug that reduces the amount of virus in the body. Anti-HIV drugs such as ddI slow down or prevent damage to the immune system, and reduce the risk of developing AIDS-related illnesses.

ddI is a nucleoside reverse transcriptase inhibitor (NRTI). NRTIs work by disrupting an HIV enzyme called reverse transcriptase which is involved in the production of new viruses. For more information about how NRTIs work, see Reverse transcriptase inhibitors.

ddI is also known by the chemical name 2’,3’-dideoxyinosine, by the generic name didanosine and by its tradenames Videx and VidexEC. It is manufactured by Bristol-Myers Squibb.

A generic version of ddI called Dinex EC is produced by the Indian manufacturer Cipla. Viro-Z and Aviro-Z are manufactured by Ranbaxy, and a tablet formulation of ddI called Divir is manufactured by the Thai government. A fixed dose combination of ddI, 3TC (lamivudine) and efavirenz, called Odivir Kit is manufactured by Cipla.