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Videx or Videx EC - didanosine - ddI

General Information This drug is almost always used as one component of a multidrug combination to suppress the human immunodeficiency (HIV) viral load.

Didanosine (ddI) is the one of the oldest drugs approved to treat HIV.  Many, many people with HIV and AIDS have been treated with this drug, and it actually has a very good track record of effectiveness and safety.  It may be used at all stages of HIV infection.


Generally didanosine is taken at 250 to 400 mg of the EC (enteric-coated) formulation once a day on an empty stomach.  If you do not eat for a couple of hours before bedtime, then bedtime is probably the ideal time to take it.  If you take it in the morning, you must wait at least an hour before you eat anything or at least 2 hours after you eat something.  You may take clear liquids or coffee or juices with didanosine.

(this refers to your willingness, ability, and actual performance in taking your medications)
As with any antiviral drug or antibiotic, try not to ever miss a dose.  If you miss a dose and notice that you have done so within a few hours of its scheduled time, you may take the dose as usual and take the next dose at its regular time.

You should not adjust or change the dosing of this medication without the advice of your healthcare provider or someone who is experienced with antiviral medications.

If you miss more than one dose, look at the reasons why you missed them and come up with a plan to avoid it in the future.  For example, if you fell asleep too early, take the medicine earlier in the evening, with your later meal, set an alarm, or have someone appointed to wake you up for your medicine.  

I would strongly recommend using weekly pill boxes and arrange all of your doses a week in advance.  Buy a small pill box so that you can carry a dose or two of your medicines with you in case you are away from home.

Possible Side Effects
The package insert for most drugs including didanosine is often overwhelming and scary with perhaps an overemphasis on side effects.  We have summarized the important and more common problems here.

Most people take didanosine without many side effects. 

Usually you will have blood tests done in the first month to look for the beneficial effects of didanosine and any side effects. 

Possible side effects include nausea, headache, muscle aches, liver problems, nerve damage, or pancreatic inflammation. 

This nerve damage is referred to as peripheral neuropathy.  Peripheral neuropathy usually begins as mild discomfort on the soles of the feet and may gradually travel up the legs depending on the length of time that you take this medication.  In many cases stopping this medication under the supervision of your provider will allow this side effect to completely go away.

Didanosine is also rarely associated with inflammation of the pancreas or pancreatitis.  The pancreas is an organ deep in the center of your abdomen that secretes insulin and digestive juices.  When the pancreas is inflamed, it essentially begins to digest itself.  As you might imagine, this process is characterized by abdominal pain, and nausea and vomiting.  It is rarely fatal.  Your provider will monitor you for this condition.   Alcohol use can cause pancreatitis so we advise patients on didanosine to avoid alcoholic beverages including coolers, beer, wine, liquor, and mixed drinks.  If you have had pancreatitis in the past, didanosine should not be taken.

All drugs of this class can cause or contribute to abnormal fat redistribution characterized by thinning of the face, arms, or legs.  In most cases this would be also accompanied by elevated cholesterol levels, elevated triglyceride levels, and perhaps a tendency to develop diabetes. 

Rarely, a build-up of (lactic) acid may occur due to taking medications of this type.  Persons taking multiple nukes (NRTIs), those taking d4T (stavudine, Zerit), those on the combination of d4T (stavudine, Zerit) and ddI (didanosine, Videx), and those persons with hepatitis C are the most likely to encounter this rare, but potentially fatal problem.  Pregnancy may also raise the risk of this problem.  The symptoms are vague but troublesome including nausea, vomiting, muscle aches, weakness, turning yellow with jaundice, and just feeling plain bad

Report to you healthcare provider or go to an Emergency Room if you have severe side effects, increasing side effects, shortness of breath, abdominal pain, uncontrollable diarrhea, weakness, jaundice (eyes and skin turn yellow,) muscle pain, nausea and vomiting so that you cannot hold down your food and liquids.
You can download this handout in PDF format by clicking HERE.