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Didanosine Enteric Coated (EC)

Other Names: Didanosine EC, Videx® EC
Manufacturer: Bristol-Myers Squibb

What is it?

Didanosine EC is an antiretroviral drug, specifically a nucleoside reverse transcriptase inhibitor. It is used to treat HIV, a retrovirus. Retroviruses use the genetic material in the body’s cells to produce more virus which can infect other cells.

How does it work?

Didanosine EC interferes with the life cycle of HIV to stop it from producing more virus. Specifically, didanosine EC ties up the reverse transcriptase enzyme so it cannot build the genetic material needed to make more virus and infect more cells.

How do I take it?

  • Didanosine EC is available as 125 mg, 200 mg, 250 mg, and 400 mg capsules, and as an oral suspension.
  • Didanosine EC is usually taken as a single daily dose. The dose will be adjusted depending upon how much you weigh.
  • For this study, you will be taking didanosine EC _______ mg ________ time(s) each day.
  • All doses must be taken on an empty stomach at least 1 hour before or 2 hours after a meal or snack.

It is extremely important that you take didanosine EC and your other antiretroviral medications exactly a s directed. You should set up a system that will help you remember to take your medicines so that you do not miss any doses. If you miss a dose, take it as soon as possible; however, if you skip a dose, do not take two doses at once. Do not stop taking the medication for any reason at any time unless you are directed to do so by your study clinician. If you are unable to continue taking your medication due to side effects, you should contact your study clinician immediately.

Special Considerations

  • Didanosine EC suspension is also available if necessary. The suspension must be shaken well before each dose, and it must be stored in the refrigerator.
  • Didanosine EC should be stored at a controlled room temperature out of the reach of children.
  • Please bring your medication bottles (empty and partially used) to each study visit.


Some drugs taken together may have interactions that cause illness or impair the effectiveness of the drugs. It is a good idea to always check with your study clinician before taking any other medications, prescription or otherwise, to be sure it will not interact with didanosine EC.

  • Didanosine EC must be taken on an empty stomach at least 1 hour before or 2 hours after a meal or snack, as food will significantly decrease the amount of didanosine EC that gets into your bloodstream.
  • Medications that are taken with food should not be taken at the same time as didanosine EC.

When taking didanosine with tenofovir (Viread®), please talk with your provider or pharmacist about how to avoid side effects. Tenofovir significantly increases the amount of didanosine in your blood stream. This may lead to a greater risk that side effects will develop.

It is possible that taking didanosine EC with other medicines that have a potential to cause peripheral neuropathy (tingling or numbing sensations in the hands and/or feet) may increase your risk of developing neuropathy.

Side Effects

Not everyone experiences side effects. When they do occur, they may be mild, moderate or severe. Some side effects cannot be felt by the patient but can be found through laboratory tests, so it is important to see your study clinician regularly for checkups so that side effects can be detected early and treated.

The most common side effects of didanosine EC are peripheral neuropathy (tingling or numbing sensations in the hands and/or feet), inflammation of the pancreas (which may cause nausea, vomiting, stomach pain), altered taste, nausea, vomiting, diarrhea, headache, and inflammation of the liver. If you begin having any of these side effects, please contact your study clinician.

Excessive consumption of alcohol may increase the risk of developing pancreatitis.


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