Drug/Small Molecule:
didanosine

2D structure

Overview

Generic Names: DDI; Dideoxyinosine
Trade Names: Videx; Videx EC
PharmGKB Accession Id: PA449301

Description

A dideoxynucleoside compound in which the 3'-hydroxy group on the sugar moiety has been replaced by a hydrogen. This modification prevents the formation of phosphodiester linkages which are needed for the completion of nucleic acid chains. Didanosine is a potent inhibitor of HIV replication, acting as a chain-terminator of viral DNA by binding to reverse transcriptase; ddI is then metabolized to dideoxyadenosine triphosphate, its putative active metabolite. PubChem (source: Drug Bank)

Indication

For use, in combination with other antiretroviral agents, in the treatment of HIV-1 infection in adults. (source: Drug Bank)

ATC Therapeutic Category

  • J05AF:Nucleoside and nucleotide reverse transcriptase inhibitors

Pharmacology, Interactions, and Contraindications

Mechanism Of Action

Didanosine (ddI) is metabolized intracellularly by a series of cellular enzymes to its active moiety, dideoxyadenosine triphosphate (ddATP), which inhibits the HIV reverse transcriptase enzyme competitively by competing with natural dATP. It also acts as a chain terminator by its incorporation into viral DNA as the lack of a 3'-OH group in the incorporated nucleoside analogue prevents the formation of the 5' to 3' phosphodiester linkage essential for DNA chain elongation, and therefore, the viral DNA growth is terminated. (source: Drug Bank)

Pharmacology

Didanosine is a nucleoside reverse transcriptase inhibitor (NRTI) with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Didanosine differs from other nucleoside analogues, as it does not have any of the regular bases, instead it has hypoxanthine attached to the sugar ring. Didanosine is phosphorylated to active metabolites that compete for incorporation into viral DNA. They inhibit the HIV reverse transcriptase enzyme competitively and act as a chain terminator of DNA synthesis. Didanosine is effective against HIV, and usually used in combination with other antiviral therapy. Switching from long term AZT treatment to didanosine has been shown to be beneficial. Didanosine has weak acid stability and therefore, it is often combined with an antacid. (source: Drug Bank)

Food Interactions

Avoid alcohol.
Take on empty stomach: 1 hour before or 2 hours after meals. (source: Drug Bank)

Absorption, Distribution, Metabolism, Elimination & Toxicity

Biotransformation

Rapidly metabolized intracellularly to its active moiety, 2,3-dideoxyadenosine-5-triphosphate (ddA-TP). It is then further metabolized hepatically to yield hypoxanthine, xanthine, and uric acid. (source: Drug Bank)

Protein Binding

Low (<5%) (source: Drug Bank)

Absorption

Rapidly absorbed (bioavailability 30-40%) with peak plasma concentrations appearing within 0.5 and 1.5 hrs. (source: Drug Bank)

Toxicity

Side effects include pancreatitis, peripheral neuropathy, diarrhea, hyperuricemia and hepatic dysfunction (source: Drug Bank)

Isomeric SMILES Code:

C1C[C@@H](O[C@@H]1CO)N2C=NC3=C2NC=NC3=O (source: Drug Bank)

A list of non-curated publications that mention this drug along with other genes is available.

A list of non-curated publications that mention this drug along with other drugs is available.

Drug Interactions

Drug Description
ganciclovir Uncurated Annotation The antiviral agent increases the effect and toxicity of didanosine (source: Drug Bank)
tenofovir Uncurated Annotation Tenofovir increases the effect and toxicity of didanosine (source: Drug Bank)
tipranavir Uncurated Annotation Didanosine EC levels may be reduced (source: Drug Bank)
valganciclovir Uncurated Annotation The antiviral agent increases the effect and toxicity of didanosine (source: Drug Bank)
zalcitabine Uncurated Annotation Additive toxicities (peripheral neuropathy) (source: Drug Bank)

Non-Curated Information

A list of non-curated publications that mention this drug along with other diseases is available.

Additional Datasets

These datasets are minimally curated and are sorted alphabetically by title.

  1. Physicochemical determinants of human renal clearance

LinkOuts

Web Resource:
Wikipedia
DrugBank:
DB00900
KEGG Compound ID:
C06953
KEGG Drug ID:
D00296
PubChem Compound ID:
50599
PubChem Substance ID:
189028

Common Searches

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Non-Curated Publications

A list of non-curated publications that mention this drug is available.

PharmGKB integrates drug information from different sources: DrugBank, Open Eye Scientific Software.
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