Title: Didanosine
CAS Registry Number: 69655-05-6
CAS Name: 2¢,3¢-Dideoxyinosine
Additional Names: dideoxyinosine; ddI; ddIno
Manufacturers' Codes: BMY-40900; NSC-612049
Trademarks: Videx (BMS)
Molecular Formula: C10H12N4O3
Molecular Weight: 236.23
Percent Composition: C 50.84%, H 5.12%, N 23.72%, O 20.32%
Literature References: Hypoxanthine nucleoside with antiviral activity; metabolic product of dideoxyadenosine, q.v. Enzymatic prepn from dideoxyadenosine: W. Plunkett, S. S. Cohen, Cancer Res. 35, 1547 (1975). Synthesis: G. W. Koszalka, T. A. Krenitsky, EP 206497 (1986 to Wellcome Found.); R. R. Webb et al., Nucleosides Nucleotides 7, 147 (1988). In vitro inhibition of HIV-I: H. Mitsuya, S. Broder, Proc. Natl. Acad. Sci. USA 83, 1911 (1986); of HIV-II: D. D. Richman, Antimicrob. Agents Chemother. 31, 1879 (1987). Antiretroviral spectrum in vitro: J. E. Dahlberg et al., Proc. Natl. Acad. Sci. USA 84, 2469 (1987). Cellular pharmacology in cloned human T-cells: G. Ahluwalia et al., Biochem. Pharmacol. 36, 3797 (1987). HPLC determn in human plasma: G. Ray, E. Murrill, Anal. Lett. 20, 1815 (1987). Clinical evaluations in AIDS: J. S. Lambert et al., N. Engl. J. Med. 322, 1333 (1990); T. P. Cooley et al., ibid. 1340. Comprehensive description: M. N. Nassar et al., Anal. Profiles Drug Subs. Excip. 22, 185-227 (1993).
Properties: White solid, mp 160-163°. Soly at 23° (mg/ml): acetone <1; acetonitrile <1; t-butanol <1; chloroform <1; dimethylacetamide 45; DMSO 200; ethanol 1; ethyl acetate <1; hexane <1; methanol 6; methylene chloride <1; polyethylene glycol-300 1; 1-propanol <1; 2-propanol <1; propylene glycol 8. pKa 9.12 ±0.02. Partition coefficient (1-octanol/0.05M phosphate buffer pH 7) 0.068 ±0.005. [a]D25 -26.3° (c = 10 in water). uv max 248 nm (pH 2); 254 nm (pH 12).
Melting point: mp 160-163°
pKa: pKa 9.12 ±0.02
Optical Rotation: [a]D25 -26.3° (c = 10 in water)
Log P: Partition coefficient (1-octanol/0.05M phosphate buffer pH 7) 0.068 ±0.005
Absorption maximum: uv max 248 nm (pH 2); 254 nm (pH 12)
Therap-Cat: Antiviral.
Keywords: Antiviral; Purines/Pyrimidinones; Reverse Transcriptase Inhibitor.
Didecyldimethylammonium Chloride Didemnins Dideoxyadenosine Dienestrol Dienochlor

Didanosine ball-and-stick.png
Systematic (IUPAC) name
Clinical data
AHFS/Drugs.com monograph
MedlinePlus a691006
Pregnancy cat. B2 (AU) B (US)
Legal status POM (UK) -only (US)
Routes Oral
Pharmacokinetic data
Bioavailability 30 to 54%
Protein binding Less than 5%
Half-life 1.5 hours
Excretion Renal
CAS number 69655-05-6 YesY
ATC code J05AF02
PubChem CID 50599
DrugBank DB00900
ChemSpider 45864 YesY
KEGG D00296 YesY
ChEBI CHEBI:490877 YesY
NIAID ChemDB 000004
Chemical data
Formula C10H12N4O3 
Mol. mass 236.227 g/mol
 YesY (what is this?)  (verify)

Didanosine (2′,3′-dideoxyinosine, ddI, DDI) is sold under the trade names Videx and Videx EC. It is a reverse transcriptase inhibitor, effective against HIV and used in combination with other antiretroviral drug therapy as part of highly active antiretroviral therapy (HAART).