Didanosine (ddI) is a nucleoside reverse transcriptase inhibitor analog of adenosine (IC50: 0.49 μM).

Reverse transcriptase:0.49 μM

In cultured human muscle cells, Didanosine induced accumulation of cytoplasmic lipid droplets, increased lactate production, and decreased SDH (part of complex II) and COX (complex IV) activity. In HIV target cells, Didanosine was converted to its active form, deoxyadenosine-5'-triphosphate (ddATP). In dissociated DRG cells in culture, Didanosine dose-dependently induced reductions in the number of neurites, the length of each neurite in the longest neurite, and the total length of the neurite. In dissociated DRG neurons, Didanosine dose-dependently induced neurite retraction or axon loss, suggesting that desipramine is useful in the development of peripheral neuropathy. In cultured human TK6 lymphoblastoid cells, Didanosine induced mutagenicity of the thymidine kinase gene induced by zidovudine.