II. Mechanism

  1. Nucleoside Reverse Transcriptase Inhibitor
  2. Purine analogue
  3. Degraded at an acidic pH (all preparations have buffer)

III. Pharmacokinetics

  1. Crosses the Blood brain barrier
  2. Actively excreted by the Kidney

IV. Efficacy

  1. Delays HIV progression to AIDS
  2. Transiently increases CD4 Counts
  3. Partially suppresses p24 antigenemia
    1. Patients with HIV disease and CD4 Count < 300 cells
    2. Received varying lengths of AZT therapy

V. Dosing

  1. Didanosine 200 mg PO bid ($186/month)
  2. Take on an empty Stomach
  3. Avoid concurrent Alcohol (exacerbates toxicity)
  4. Take Medications requiring acidic pH 2 hours after ddI

VI. Adverse Effects

  1. See nRTI for adverse effects attributed to the class
  2. Adverse effects are increased when used in combination with Stavudine
  3. Peripheral Neuropathy
  4. Pancreatitis - most serious toxicity!
    1. Incidence
      1. Dose 500 mg/day: 7% Pancreatitis
      2. Dose 750 mg/day: 9% Pancreatitis
    2. Increased risk if Hyperamylasemia
      1. Dose 500-750 mg/day: 18% Hyperamylasemia
    3. Interrupt therapy if suspect Pancreatitis
    4. Avoid other pancreatic toxins (e.g. Pentamidine)
  5. Eye related changes
    1. Retinal changes
    2. Optic Neuritis
  6. Hyperamylasemia
  7. Hyperuricemia
  8. Dry Mouth
  9. Gastrointestinal changes
    1. Gastrointestinal upset
    2. Hepatic toxicity
    3. Noncirrhotic Portal Hypertension
  10. Electrolyte imbalances (rare)
  11. Cardiac arrhythmias (rare)

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Ontology: Didanosine (C0012133)

Definition (NCI) A nucleoside reverse transcriptase inhibitor analog of adenosine.
Definition (NCI_NCI-GLOSS) A drug used to treat infection caused by viruses.
Definition (CSP) inosine nucleoside analog; antiHIV agent.
Definition (MSH) A dideoxynucleoside compound in which the 3'-hydroxy group on the sugar moiety has been replaced by a hydrogen.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.
Definition (PDQ) A synthetic nucleoside analogue of deoxyadenosine in which the 3' hydroxyl on the ribose moiety is replaced by a hydrogen atom. In vivo, didanosine is converted to the active triphosphate form, which is incorporated into DNA. The absence of the 3' hydroxyl inhibits DNA elongation because phosphodiester bonds cannot be made with the substituted hydrogen. Check for "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=37814&idtype=1" active clinical trials or "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=37814&idtype=1&closed=1" closed clinical trials using this agent. ("http://nciterms.nci.nih.gov:80/NCIBrowser/ConceptReport.jsp?dictionary=NCI_Thesaurus&code=C431" NCI Thesaurus)
Concepts Pharmacologic Substance (T121) , Nucleic Acid, Nucleoside, or Nucleotide (T114)
MSH D016049
SnomedCT 75818008, 19194001, 387105006
LNC LP21309-7, MTHU013844
English 2',3' Dideoxyinosine, 2',3'-Dideoxyinosine, ddI (Antiviral), Didanosine, Dideoxyinosine, 2'3' dideoxyinosine, Inosine, 2',3'-dideoxy-, Didanosine EC, DIDEOXYINOSINE 002 003, DDI, didanosine (medication), didanosine, DIDANOSINE, Didanosine [Chemical/Ingredient], ddi, 2 3 dideoxyinosine, Dideoxyinosine (product), ddI, Didanosine (product), Didanosine (substance), dideoxyinosine, Dideoxyinosine -RETIRED-
Swedish Didanosin
Czech dideoxyinosin
Finnish Didanosiini
Russian DDI (PROTIVOVIRUSNYI), 2',3'-DIDEZOKSIINOZIN, DIDANOZIN, DIDEZOKSIINOZIN, 2',3'-ДИДЕЗОКСИИНОЗИН, ДДИ (ПРОТИВОВИРУСНЫЙ), ДИДАНОЗИН, ДИДЕЗОКСИИНОЗИН
Japanese ジデオキシイノシン, 2',3'-ジデオキシイノシン, ジダノシン
Italian 2',3'-Dideossiinosina, Antivirale del ddI, Dideossiinosina, Didanosina
German DIDESOXYINOSIN 002 003, 2',3'-Didesoxyinosin, DDI (Antiviral), Didanosin, Didesoxyinosin
Polish Dideoksyinozyna, Didanozyna
Portuguese 2',3'-Didesoxi-Inosina, Didesoxi-Inosina, ddI (Antiviral), Didanosina
Spanish 2',3'-dideoxinosina, didesoxinosina-RETIRADO- (concepto no activo), 2´,3´-didesoxinosina, didesoxinosina-RETIRADO-, didanosina (producto), didanosina (sustancia), didanosina, ddI, 2',3'-Didesoxiinosina, ddI (Antiviral), Didanosina, Didesoxiinosina
French Didéoxyinosine

Ontology: Videx (C0592249)

Concepts Pharmacologic Substance (T121) , Nucleic Acid, Nucleoside, or Nucleotide (T114)
MSH D016049
English videx, Videx, Bristol Myers Brand of Didanosine, Bristol Myers Squibb Brand of Didanosine, Bristol-Myers Brand of Didanosine, Bristol-Myers Squibb Brand of Didanosine