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Test Positive Aware Network
Videx and Videx EC (Didanosine, ddI)
January/February 2008
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Brand Name: Videx & Videx EC
Common Name: didanosine or ddI
Class: nucleoside analog (also called nucleoside reverse transcriptase inhibitor, NRTI or nuke)
Standard Dose: One 400 mg enteric coated (Videx EC) delayed-release capsule once a day, with adjustments for weight and when combined with Viread, Truvada, or Atripla. (Also available in 125 mg, 200 mg and 250 mg caps.) Videx is also available as a buffered powder for oral solution. Take Videx and Videx EC strictly on an empty stomach (unless taking with Viread), one hour before or two hours after food or drink, except water. A reduced dose may be needed for people with kidney problems. Take missed dose as soon as possible, but do not double up on your next dose. Generic Videx EC is available.
AWP: $367.93 for Videx EC (generic enteric-coated $344.92) / month
Manufacturer contact: Bristol-Myers Squibb,
www.bmsvirology.com, 1 (800) 272–4878
AIDSInfo: 1 (800) HIV–0440 (448–0440), www.aidsinfo.nih.gov
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| Potential side effects and toxicity: |
Peripheral neuropathy (tingling, burning, numbness or pain in the hands or feet) may go away once ddI is stopped, but can be painful and permanently debilitating if not treated in time and occurs more frequently when used with Zerit. Upset stomach, diarrhea, headache, and more rarely pancreatitis (inflammation of the pancreas) have also been reported. Other toxicities include eye changes and optic neuritis. Have periodic eye exams by someone who is aware you are HIV-positive. Increased uric acid levels (indicating a number of disorders, including kidney damage and metabolic diseases), and insomnia are other potential side effects. Rare but potentially fatal toxicity with all NRTIs is pancreatitis, enlarged fatty liver, and lactic acidosis (accumulation of lactate in the blood and abnormal acid-base balance). Lactic acidosis has been seen in patients taking NRTIs but is more common and more severe in women, people who are obese, and people who have been taking nukes for a long time; and more common in people with liver disease, but can occur in people without a history of liver damage. People with lactic acidosis may experience persistent fatigue, abdominal pain or distension, nausea/vomiting, and difficulty breathing or shortness of breath; and enlarged, fatty liver. People with a history of peripheral neuropathy, pancreatitis or heavy alcohol use should avoid ddI. Pancreatitis can be life-threatening and may cause pain in the stomach and back, along with nausea, vomiting and blood in the urine. Risks for pancreatitis include: higher than recommended doses of NRTIs, advanced HIV, and alcohol use. Stop all HIV medications and see a health care provider immediately. Body fat redistribution/accumulation has also been reported with ddI.
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| Potential drug interactions: |
| The levels of ddI are increased by 44–60% when given at the same time as Viread, therefore a dose reduction to 250 mg for Videx is recommended if you weigh more than 60 kg (132 pounds). See Viread page. The combined use of ddI and zidovudine or hydroxyurea may increase risk of peripheral neuropathy. Combining ddI with Zerit or with hydroxyurea, alcohol, ganciclovir, valganciclovir, or intravenous (not inhaled) pentamidine may increase risk of pancreatitis. Combining ddI with Zerit may increase the risk of lactic acidosis. Also, ganciclovir and ribavirin substantially increase ddI levels, and are generally recommended not to be taken together. Didanosine oral solution should be taken on an empty stomach two hours apart from protease inhibitors, Tagamet (cimetidine), ketoconazole, itraconazole, and dapsone, and one hour apart from Rescriptor, while Videx EC can be taken with them, but still on an empty stomach. With Viread, it may be taken with a light snack (low-fat, 373 calories). The dose of ddI may need to be increased when taken with methadone. |
| Tips: |
Study indicates Videx EC (compared to Videx) may have lower risk of peripheral neuropathy. Either drug taken with Zerit increases the risk of facial wasting, pancreatitis, or lactic acidosis. Swallow the capsules whole. The capsules eliminate the bad taste and texture of the tablets and the enteric coating reduces diarrhea. Absorption can be decreased by as much as 50% when taken with food, so take on an empty stomach. If you have reduced kidney function, you may require a lower dose. Notify your doctor immediately if peripheral neuropathy is suspected. Please see package insert for more complete potential side effects and interactions.
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| Doctor |
| In the pre-HAART era, Videx was the drug we often went to when Retrovir failed. It wasn't fun to take -- you had to chew it or drink it or mix it with antacids twice a day. It tasted awful, and it caused diarrhea. The enteric coated (EC) formulation turned Videx into a simple pill like all the rest, but it still has its problems. Like Zerit, it can cause neuropathy. It can also cause pancreatitis, a potentially life-threatening inflammation of the pancreas. It may cause mitochondrial toxicity, too, though it's hard to know for sure because it's been studied mostly with two other drugs that cause the same problem: d4T and AZT. I use ddI occasionally -- usually in people whose virus is resistant to other nukes. It should never be combined with Zerit, and if it's taken with Viread, Truvada, or Atripla, it should be given at a lower dose.-- Joel Gallant, M.D. |
| Activist |
| Videx/ddI, like AZT, is one of the oldest drugs developed for HIV. Early versions of the drug were large pills that were difficult to swallow or drink after being dissolved in water. A later, much improved enteric-coated version called Videx EC overcame these problems, though the underlying side effects of the drug remained. Videx was the first drug widely distributed in an expanded access program, under which it was given to more than 17,000 people in the U.S. alone who had already developed resistance to AZT. It was the only alternative in those days. But the widespread distribution quickly uncovered two major side effects in the form of pancreatitis and peripheral neuropathy. Research in later years found these problems to be a likely consequence of mitochondrial toxicity, a problem shared with any of the "d" drugs (ddI, ddC, d4T). These are serious lifelong problems and pancreatitis can be fatal. To be fair, such problems are most likely to occur in people with very advanced disease. Therefore, Videx is probably not a good choice under that circumstance. A recent laboratory study concluded that Videx/ddI was perhaps the worst cause of mitochondrial toxicity, followed by AZT. Problems like this are the reasons that some researchers are urging the retirement of the older nucleoside analogue drugs. The main use today for Videx is in people who have run out of other options due to the development of resistance. -- Martin Delaney |
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This article was provided by Test Positive Aware Network. It is a part of the publication Positively Aware.
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