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didanosine (ddI, 2,3-dideoxyinosine)

Videx, Videx EC

Pharmacologic class: Nucleoside reverse transcriptase inhibitor

Therapeutic class: Antiretroviral, antiviral

Pregnancy risk category B

FDA Box Warning

• Pancreatitis has occurred when drug was used alone or in combination regimens in treatment-naive or treatment-experienced patients. Suspend therapy in patients with suspected pancreatitis; discontinue in patients with confirmed pancreatitis.

• Drug may cause lactic acidosis and severe hepatomegaly with steatosis when used alone or in combination with other antiretrovirals. Fatal lactic acidosis has occurred in pregnant women receiving didanosine-stavudine combination with other antiretrovirals. In pregnant patients, use this combination with caution and only if benefit clearly outweighs risk.


Inhibits replication of human immunodeficiency virus (HIV) by disrupting synthesis of DNA polymerase, an enzyme crucial to DNA and RNA formation


Capsules (delayed-release): 125 mg, 200 mg, 250 mg, 400 mg

Powder for oral solution (pediatric): 2 g in 4-oz glass bottle, 4 g in 8-oz glass bottle

Indications and dosages

HIV infection

Adults weighing 60 kg (132 lb) or more: 400 mg (capsules) P.O. once daily

Adults weighing less than 60 kg (132 lb): 250 mg (capsules) P.O. once daily

Children: 120 mg/m2 (powder for oral solution, pediatric) P.O. q 12 hours

Dosage adjustment

• Renal impairment


• Hypersensitivity to drug

• Concurrent use of allopurinol or ribavirin


Use cautiously in:

• renal or hepatic impairment, peripheral neuropathy, hyperuricemia

• elderly patients

• pregnant or breastfeeding patients

• children.


• Know that drug is usually given in conjunction with other antiretrovirals.

• Give on empty stomach 30 minutes before or 2 hours after a meal.

• Don't administer with fruit juice.

• Know that pharmacist must prepare pediatric powder for oral solution by diluting with water and antacid to a concentration of 10 mg/ml.

• Be aware that delayed-release capsules aren't intended for use in children.

Adverse reactions

CNS: dizziness, anxiety, abnormal thinking, hypoesthesia, agitation, confusion, hypertonia, asthenia, peripheral neuropathy, seizures, coma

CV: peripheral coldness, palpitations, hypotension, bradycardia, weak pulse, pseudoaneurysm, incomplete atrioventricular (AV) block, complete AV block, nodal arrhythmias, ventricular tachycardia, thrombophlebitis, embolism

EENT: diplopia, abnormal vision, ocular hypotony, iritis, retinal detachment

GI: nausea, vomiting, diarrhea, abdominal enlargement, dyspepsia, ileus, GI reflux, hematemesis, dysphagia, dry mouth, pancreatitis

GU: urinary retention, frequency, or incontinence; dysuria; cystalgia; prostatitis; renal dysfunction; nephrotoxicity

Hematologic: anemia, leukocytosis, thrombocytopenia, bleeding, neutropenia

Hepatic: hepatomegaly with steatosis, noncirrhotic portal hypertension

Metabolic: diabetes mellitus, hyperkalemia, lactic acidosis, noncirrhotic portal hypertension

Musculoskeletal: muscle contractions

Respiratory: pneumonia, crackles, rhonchi, bronchitis, pleurisy, dyspnea, wheezing, pleural effusion, pulmonary edema, pulmonary embolism, bronchospasm

Skin: diaphoresis, pallor, rash, urticaria, pruritus, bullous eruption, petechiae, cellulitis, abscess

Other: edema, development of human antichimeric antibodies


Drug-drug. Allopurinol, ganciclovir (oral), ribavirin, tenofovir: increased didanosine blood level

Amprenavir, delavirdine, indinavir, ritonavir, saquinavir: altered didanosine pharmacokinetics

Antacids, other drugs that increase gastric pH: increased risk of didanosine toxicity

Co-trimoxazole, pentamidine: increased risk of pancreatic toxicity

Dapsone, fluoroquinolones, ketoconazole: decreased blood levels of these drugs

Itraconazole: decreased itraconazole blood level

Methadone: 50% decrease in didanosine blood level

Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, bilirubin, uric acid: increased levels

Granulocytes, hemoglobin, platelets, white blood cells: decreased values

Drug-food. Any food: decreased rate and extent of drug absorption

Patient monitoring

Monitor patient for signs and symptoms of pancreatitis. Withhold drug in patients with signs or symptoms of pancreatitis and discontinue drug in patients with confirmed pancreatitis.

Monitor patient for early signs and symptoms of portal hypertension (thrombocytopenia, splenomegaly). Discontinue drug in patients with evidence of noncirrhotic portal hypertension.

Assess carefully for signs and symptoms of lactic acidosis, such as dizziness, light-headedness, and bradycardia.

• Monitor for signs and symptoms of peripheral neuropathy.

• In patients with renal impairment, watch for drug toxicity and hypermagnesemia (suggested by muscle weakness and confusion).

Patient teaching

• Tell patient to take drug on empty stomach.

• Advise patient using buffered powder to mix it with water, not juice, and to let powder dissolve for several minutes before taking.

Instruct patient to immediately report abdominal pain, nausea, vomiting, tiredness, fast or irregular heartbeats, easy bruising, difficulty breathing, yellowing of skin or eyes, or dark urine.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and foods mentioned above.

McGraw-Hill Nurse's Drug Handbook, 7th Ed. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved


(dye-dan-oh-seen) ,


(trade name),

Videx EC

(trade name)


Therapeutic: antiretrovirals
Pharmacologic: nucleoside reverse transcriptase inhibitors
Pregnancy Category: B


HIV infection (with other antiretrovirals).


Inhibits viral replication by interfering with viral RNA-directed DNA polymerase (reverse transcriptase). Converted intracellularly by the phosphorylation process to its active form.

Therapeutic effects

Increase in CD4 cell counts and decreased viral load, with decreased incidence of opportunistic infections and slowed progression in HIV-infected patients.


Absorption: Rapidly degrades at gastric pH.
Distribution: CSF levels are 21% of plasma levels in adults.
Metabolism and Excretion: Metabolized as a purine; 55% eliminated by the kidneys (18% as unchanged drug; urinary excretion is less in children).
Half-life: 1.6 hr (0.8 hr in children).

Time/action profile (antiretroviral plasma levels)

POunknown 0.25–1.5 hr12 hr


Contraindicated in: Hypersensitivity; Lactation: Lactation; Concurrent use of ribavirin or allopurinol.
Use Cautiously in: History of gout; Renal impairment (dosage modification required if CCr <60 mL/min; ↑ risk of pancreatitis); History of seizures; Diabetes mellitus; Pediatric: ↑ risk of pancreatitis.

Adverse Reactions/Side Effects

Central nervous system

  • seizures (life-threatening)
  • headache (most frequent)
  • dizziness
  • insomnia
  • lethargy
  • pain
  • weakness

Ear, Eye, Nose, Throat

  • rhinitis (most frequent)
  • ear pain
  • epistaxis
  • optic neuritis
  • parotid gland enlargement
  • photophobia
  • retinal depigmentation
  • sialoadenitis


  • cough (most frequent)
  • asthma


  • arrhythmias
  • edema
  • hypertension
  • vasodilation


  • hepatomegaly (with steatosis) (life-threatening)
  • liver failure (life-threatening)
  • non-cirrhotic portal hypertension (life-threatening)
  • pancreatitis (life-threatening)
  • anorexia (most frequent)
  • diarrhea (most frequent)
  • ↑ liver function tests (most frequent)
  • nausea (most frequent)
  • vomiting (most frequent)
  • abdominal pain
  • constipation
  • dry mouth
  • dyspepsia
  • flatulence
  • stomatitis


  • urinary frequency


  • alopecia
  • ecchymoses
  • rash


  • fat redistribution
  • hyperglycemia


  • granulocytopenia (most frequent)
  • anemia
  • bleeding
  • leukopenia


  • lactic acidosis (life-threatening)
  • hyperlipidemia
  • hyperuricemia
  • weight loss


  • rhabdomyolysis (life-threatening)
  • arthritis
  • myalgia


  • peripheral neuropathy (most frequent)
  • poor coordination


  • chills (most frequent)
  • fever (most frequent)
  • anaphylactoid reactions
  • immune reconstitution syndrome


Drug-Drug interaction

Ribavirin and allopurinol ↑ levels and risk of toxicity (concurrent use not recommended).Levels are ↑ by tenofovir (dose reduction recommended).Concurrent use with ganciclovir ↑ levels (dose adjustments may be necessary).Methadone ↓ levels of didanosine (dose adjustments may be necessary).Buffers in didanosine ↑ absorption of ketoconazole, itraconazole, dapsone, tetracyclines, and fluoroquinolones (do not administer within 2 hr of didanosine).↑ risk of peripheral neuropathy with isoniazid, phenytoin, stavudine, ethambutol, and chloramphenicol (use cautiously).↑ risk of pancreatitis with other alcohol, thiazide diuretics, IV pentamidine, tetracyclines (use with extreme caution).↑ risk of bone marrow depression with other drugs causing bone marrow depression.Concurrent use with stavudine during pregnancy ↑ the risk of fetal lactic acidosis.Administration with food ↓ absorption by 50%.


Oral (Adults ≥60 kg) Oral solution—200 mg bid; Videx EC capsules—400 mg once daily; with tenofovir—250 mg once daily.
Oral (Adults <60 kg) Oral solution—125 mg bid; Videx EC capsules—250 mg once daily; with tenofovir—200 mg once daily.
Oral (Children 2 wk-8 mo) Oral solution—100 mg/m2 q 12 hr.
Oral (Children >8 mo) Oral solution—120 mg q 12 hr;.
Oral (Children 6–18 yr and ≥20 kg) Videx EC capsules—20–24.9 kg: 200 mg once daily; 25–59.9 kg: 250 mg once daily; ≥60 kg: 400 mg once daily.

Renal Impairment

Oral (Adults >60 kg) CCr 30–59 mL/min— Oral solution—100 mg q 12 hr or 200 mg once daily; Videx EC capsules—200 mg once daily; CCr 10–29 mL/min—Oral solution—150 mg once daily; Videx EC capsules—125 mg once daily; CCr <10 mL/min—Oral solution—100 mg once daily; Videx EC capsules—125 mg once daily.
Oral (Adults <60 kg) CCr 30–59 mL/min—Oral solution—75 mg q 12 hr or 150 mg once daily; Videx EC capsules—125 mg once daily; CCr 10–29 mL/min—Oral solution—100 mg once daily; Videx EC capsules—125 mg once daily; CCr <10 mL/min—Oral solution—75 mg once daily; Videx EC capsules—not to be used.

Availability (generic available)

Delayed-release capsules (with enteric-coated beadlets): 125 mg, 200 mg, 250 mg, 400 mg
Pediatric powder for oral solution (requires reconstitution) : 10 mg/mL

Nursing implications

Nursing assessment

  • Monitor for change in severity of HIV symptoms and for symptoms of opportunistic infection before and during therapy.
  • Monitor patient for peripheral neuropathy (distal numbness, tingling, or pain in feet or hands) during therapy. Dose may need to be decreased.
  • Monitor for symptoms of pancreatitis (abdominal pain, nausea, vomiting, increased amylase, lipase, or triglyceride concentrations). If amylase is elevated 1.5–2 times the normal limit and/or the patient has symptoms of pancreatitis, didanosine should be discontinued. Pancreatitis may be fatal.
  • May cause lactic acidosis and severe hepatomegaly with steatosis; increased risk in patients who are female, obese, or receiving nucleoside analog medications for extended periods of time. Monitor patient for signs (increased serum lactate levels, elevated liver enzymes, liver enlargement on palpation). Therapy should be suspended if clinical or laboratory signs occur.
  • Assess for signs of non-cirrhotic portal hypertension (elevated liver enzymes, esophageal varices, hematemesis, ascites, and splenomegaly); may occur months or years after starting therapy. Monitor for early signs (thrombocytopenia and splenomegaly) during therapy. Discontinue didanosine if signs occur; may lead to liver transplantation or death.
  • Lab Test Considerations: Monitor viral load and CD4 count before and routinely during therapy to determine response.
    • Monitor CBC, hepatic function, and uric acid concentrations during therapy. May cause leukopenia, granulocytopenia, thrombocytopenia, and anemia. May cause ↑ AST, ALT, alkaline phosphatase, bilirubin, uric acid, amylase, lipase, and triglyceride concentrations.Lactic acidosis may occur with hepatic toxicity causing hepatic steatosis; may be fatal, especially in women. Monitor liver enzymes, serum bilirubin, albumin, complete blood count, and international normalized ratio (INR) and ultrasonography routinely; may be ↑ in patients with non-cirrhotic portal hypertension.
    • May cause hyperglycemia.
    • Monitor serum potassium concentrations routinely liver enzymes, serum bilirubin, albumin, complete blood count, and 119 international normalized ratio (INR) and ultrasonography should be considered. VIDEX should 120 be discontinued in patients with evidence of non-cirrhotic portal hypertension.

Potential Nursing Diagnoses

Risk for infection (Indications,  Side Effects)
Risk for injury (Side Effects)


  • Commonly identified by abbreviation “ddI,” but generic and brand names should be used when ordering to prevent errors.
    • If solution or powder spills or leaks, a wet mop or damp sponge should be used for cleaning to avoid generation of dust. Clean surface with soap and water as needed.
  • Oral: Administer every 12 hr on an empty stomach, 30 min before or 2 hr after meals. Do not administer ketoconazole, dapsone, tetracyclines, or fluoroquinolones within 2 hr (6 hr for ciprofloxacin) of didanosine.
    • Swallow capsules whole; do not open, crush, or chew.
    • Solution for pediatric use is mixed by pharmacist and is stable for 30 days if refrigerated. Shake admixture immediately before administering.

Patient/Family Teaching

  • Instruct patient on the importance of taking didanosine exactly as directed, even if feeling better. Caution patient not to share or trade this medication with others.
  • May cause dizziness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
  • Inform patient that didanosine may cause hyperglycemia. Advise patient to notify health care professional if increased thirst or hunger; unexplained weight loss; increased urination; fatigue; or dry, itchy skin occurs.
  • Instruct patient to notify health care professional immediately if symptoms of lactic acidosis (tiredness or weakness, unusual muscle pain, trouble breathing, stomach pain with nausea and vomiting, cold especially in arms or legs, dizziness, fast or irregular heartbeat) or if signs of hepatotoxicity (yellow skin or whites of eyes, dark urine, light-colored stools, lack of appetite for several days or longer, nausea, abdominal pain) occur. These symptoms may occur more frequently in patients that are female, obese, or have been taking medications like didanosine for a long time.
  • Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care professional before taking other Rx, OTC, or herbal products,.
  • Caution patient to avoid crowds and persons with known infections.
  • Advise patient to notify health care professional immediately if numbness or tingling of the hands or feet, occurs.
  • Caution patient to use a condom to prevent transmission of HIV and not to share needles with anyone.
  • Inform patient that redistribution and accumulation of body fat may occur, causing central obesity, dorsocervical fat enlargement (buffalo hump), peripheral wasting, breast enlargement, and cushingoid appearance. The cause and long-term effects are not known.
  • Children should have dilated retinal exams every 3–6 mo or if there is a change in vision throughout therapy.
  • Emphasize the importance of regular exams to monitor for side effects.

Evaluation/Desired Outcomes

  • Decreased incidence of opportunistic infection and slowed progression of HIV infection.
Drug Guide, © 2015 Farlex and Partners


Didanosine–ddI, see there.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
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Buyer: New Mill Capital Holdings, Perry Videx and Infinity Asset Solutions
We are lucky our gamble has paid off and the boat has been responding so well," Videx's Pennesi said.
Videx's national sales manager Neil Thomas explained: "The market for our products increases during a recession, when you typically get higher crime rates.
Videx, approved in 1991, and Videx EC, approved in 2000, are used in combination with other antiretroviral medications to treat HIV infection in pediatric and adult patients.
When the UAB team also figured the impact of" different medications on treatment duration, they found that taking Videx or Zerit increased the risk of stopping treatment 92%.
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CyberLock Safe Locks from Videx bring full-function access control and an audit trail to safes.
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Perry Videx, Hainesport, New Jersey, USA said that the first machine to use bagasse, the dry dusty pulp that remains after juice is extracted from sugar cane or similar plants, for furnish is about to get a second life.