In 2005, the FDA approved the drug deferasirox (Exjade), an oral chelating agent for treating chronic iron overload due to multiple blood transfusions. Until then, the only way to treat iron overload was with daily prolonged intravenous therapy. Chelating agents grab metal atoms, forming complexes that can be excreted in the urine. Their use is standard treatment for heavy metal poisoning. Many popular but unproven and unapproved "alternative therapies" for cardiovascular disease, multiple sclerosis, and other chronic conditions claim to use the process of chelation.
It would be convenient to have a safe and effective orally active chelating agent, especially for iron. However, on May 22, 2007 the FDA and the drug manufacturer, Novartis, warned doctors that Exjade has been associated with some cases of kidney failure and other serious medical complications, some of which were fatal. Most of the patients involved had advanced, pre-existing blood disorders; a few had bone marrow failure.
I'm aware that various oral chelating agents are promoted on the Internet for everything from removing mercury from the body to treating chronic fatigue syndrome. There is no scientific evidence for the effectiveness of these products. Intravenous chelation therapy (with a compound called EDTA) is effective, but will do nothing for diseases unrelated to toxic metals in the body. Because MS does not have such an association, chelation therapy is not indicated for it.
By the way, I've always been skeptical of claims that IV chelation effectively removes plaque from arteries (supposedly by extracting calcium from it). This issue may finally be settled when the National Center for Complementary and Alternative Medicine completes a five-year, $30 million study of EDTA chelation therapy in patients with heart disease. The study, called TACT (Trial to Assess Chelation Therapy), is recruiting volunteers and will conclude in 2009. For more information, go to http://clinicaltrials.gov/show/NCT00044213.
Bottom line: chelation therapy, whether oral or IV has no role in the treatment of MS.
Andrew Weil, M.D.