Didanosine

Didanosine is a prescription medication used in combination with other antiretroviral agents for the treatment of human immunodeficiency virus (HIV)-1 infection.

• Didanosine is available under the following different brand names: Videx, Videx EC.

Common side effects of Didanosine include:

• headache
• diarrhea
• mild skin rash
• changes in the shape or location of body fat (especially in your arms, legs, face, neck, breasts, and waist)

Serious side effects of Didanosine include:

• hives
• difficulty breathing
• swelling of theface, lips, tongue, or throat
• unusual muscle pain
• stomach pain
• vomiting
• irregular heart rate
• dizziness
• feeling cold
• weakness
• tiredness
• numbness, tingling, or pain in the hands or feet
• bloody or tarry stools
• coughing up blood
• vomit that looks like coffee grounds
• vision changes
• loss of appetite
• upper stomach pain (that may spread to the back)
• nausea
• vomiting
• fast heart rate
• dark urine
• yellowing of the skin or eyes (jaundice)
• fever
• night sweats
• swollen glands
• cold sores
• cough
• wheezing
• diarrhea,
• weight loss
• trouble speaking or swallowing
• problems with balance or eye movements
• pricky feeling
• swelling in the neck or throat (enlarged thyroid)
• menstrual changes
• impotence

Rare side effects of Didanosine include:

• none 

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, coordination loss, unsteady, very stiff muscles, high fever, profuse sweating, or tremors.
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.
• Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult and pediatric dosage

Capsule, extended-release

• 125 mg
• 200 mg
• 250 mg
• 400 mg

Powder for oral solution

• 10 mg/mL (reconstituted)

Tablet for oral suspension

• 100 mg
• 150 mg
• 200 mg

Powder for oral solution

• 2 g
• 4 g

HIV Infection

Adult dosage

• Weighing 60 kg and lower: Extended-release 250 mg orally once a day; 125 mg orally every 12 hours
• Weighing above 60 kg: Extended-release 400 mg orally once a day; suspension 200 mg orally every 12 hours

Pediatric dosage

Oral solution

• NIH HIV guidelines (March 2016)
  • 2 weeks to less than 3 months: 50 mg/m² orally every 12 hours  
  • 3-8 months: 100 mg/m² orally every 12 hours
  • More than 8 months: 120 mg/m² (range 90-150 mg/m²) orally every 12 hours
• Manufacturer prescribing information
  • 2 weeks to 8 months: 100 mg/m² orally every 12 hours  
  • More than 8 months: 120 mg/m² orally every 12 hours  

Capsule

• Weight-based dosing (6-18 years)
  • Children who can safely swallow enteric-coated beadlets or delayed-release capsules (Videx EC or generic capsules)
  • 20 to less than 25 kg: 200 mg orally once a day
  • 25 to less than 60 kg: 250 mg orally once a day
  • 60 kg and more: As adults; 400 mg orally once a day (oral suspension: 200 mg orally every 12 hours)

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, healthcare provider, or pharmacist first.

• Didanosine has severe interactions with the following drugs:
• elvitegravir/cobicistat/emtricitabine/tenofovir DF
  • febuxostat
  • ribavirin
• Didanosine has serious interactions with the following drugs:
  • allopurinol
  • betibeglogene autotemcel
  • busulfan
  • cabotegravir
  • ciprofloxacin
  • elivaldogene autotemcel
  • gemifloxacin
  • hydroxyurea
  • levofloxacin
  • moxifloxacin
  • ofloxacin
  • pexidartinib
  • selinexor
• Didanosine has moderate interactions with at least 44 other drugs
• Didanosine has minor interactions with the following drugs:
  • ampicillin
  • ethanol
  • ferric carboxymaltose
  • ferric gluconate
  • ferric maltol
  • ferrous fumarate
  • ferrous gluconate
  • ferrous sulfate
  • food
  • isoniazid
  • metronidazole
  • nelfinavir
  • nitrofurantoin
  • pentamidine
  • polysaccharide iron
  • posaconazole
  • rose hips
  • valganciclovir
  • zidovudine

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, health questions, or concerns.

Contraindications

• Hypersensitivity
• Coadministration with allopurinol (may increase didanosine toxicity)
• Coadministration with ribavirin (increases active metabolite dideoxy adenosine 5’-triphosphate levels, causing fatal hepatic failure, peripheral neuropathy, pancreatitis, and symptomatic hyperlactatemia/lactic acidosis)
• Coadministration with stavudine

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Didanosine?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Didanosine?”

Cautions

• (All NRTIs): Risk of potentially fatal lactic acidosis & severe hepatomegaly with steatosis when used alone or in combination with other antiretrovirals
• Risk of potentially fatal pancreatitis increases if used in combo with stavudine
• Risk of potentially fatal bleeding from esophageal varices in patients with non-cirrhotic portal hypertension
• Discontinue if pancreatitis occurs; reduce dose for other adverse events
• Risk of immune reconstitution syndrome if used in combination with/ other antiretroviral drugs
• Risk of retinal changes and optic neuritis
• Rapidly degrades in acidic pH, however, enteric coating is protected from stomach acids
• Noncirrhotic portal hypertension reported; discontinue if signs/symptoms occur (eg, elevated liver enzymes, esophageal varices, hematemesis, ascites, splenomegaly)
• Coadministration of methadone with Videx pediatric powder may significantly decrease didanosine concentrations
• Patients treated in combination with stavudine may be at increased risk for pancreatitis, lactic acidosis, and hepatic toxicity; coadministration is contraindicated
• Treatment has been associated with loss of subcutaneous fat, which is most evident in the face, limbs, and buttocks; incidence and severity of lipoatrophy are related to cumulative exposure, and is often not reversible when treatment is stopped; patients receiving therapy should be frequently examined and questioned for signs of lipoatrophy, and if feasible, therapy should be switched to an alternative regimen if there is suspicion of lipoatrophy

Pregnancy and Lactation

• To monitor maternal-fetal outcomes of pregnant women exposed to didanosine and other antiretroviral agents, an Antiretroviral Pregnancy Registry has been established; physicians are encouraged to register patients by calling 1-800-258-4263
• There are no adequate and well-controlled studies of didanosine in pregnant women; the drug should be used during pregnancy only if the potential benefit justifies the potential risk
• Lactation
  • The CDC recommend that HIV-infected mothers not breastfeed infants to avoid risking postnatal transmission of HIV; a study in rats showed that following oral administration, didanosine and/or its metabolites were excreted into the milk of lactating rats; it is not known if didanosine is excreted in human milk; because of both potential for HIV transmission and potential for serious adverse reactions in nursing infants, mothers should be instructed not to breastfeed if they are receiving didanosine