didanosine

Didanosine (ddI) is a purine nucleoside reverse transcriptase inhibitor (NRTI) used primarily in the treatment of HIV-1 infection as part of antiretroviral therapy (ART). Developed by the National Cancer Institute and licensed to Bristol Myers Squibb, it was approved by the FDA in 1991 as the second drug for HIV treatment. Didanosine is a prodrug that undergoes intracellular conversion into its active metabolite, dideoxyadenosine triphosphate (ddATP). This active form competes with the natural substrate deoxyadenosine triphosphate (dATP) for incorporation into the nascent viral DNA chain by the HIV reverse transcriptase enzyme. Because didanosine lacks the 3'-hydroxyl group required for the formation of 5' to 3' phosphodiester bonds, its incorporation leads to premature DNA chain termination, effectively halting viral replication. While historically significant, its clinical use has decreased due to the risk of serious adverse effects such as pancreatitis and peripheral neuropathy, and the development of newer NRTIs with superior safety profiles.

Brand names

VidexVidex EC

Other names

2',3'-dideoxyinosinedideoxyinosine