Posted on Sun, Mar. 26, 2006
Medical Edge

Wonder drugs don’t exist for MS; stick with proven options

Dear Mayo Clinic: I am 54 years old and have recently been diagnosed with multiple sclerosis. I will have MRI scans of the brain and spine to confirm. What do you think of low-dose naltrexone and NeuroVax?

Answer: MS is a potentially debilitating disease that affects the central nervous system. It is an immune-mediated disease, which means that your immune system attacks part of your body. In MS, the body directs antibodies and white blood cells against the myelin sheaths that surround nerves in your brain and spinal cord. This process causes inflammation and injury to the sheaths and ultimately to the nerves themselves. As a result, there may be multiple areas of scarring (sclerosis), which eventually slow or block the nerve signals that control muscle coordination, strength, sensation, vision and bladder and sexual function.

While MS is rarely fatal, it is a chronic condition that can be disabling and exert limits on one’s life – as in the ability to pursue a career or put in a full day’s effort. And because MS has no known cure, patients are constantly subjected – in the lay press, on the Internet and through word of mouth – to claims of supposed breakthroughs.

Naltrexone and NeuroVax, for example, have received much attention – though not yet from the medical community – as potential treatments for MS. Naltrexone, an opioid antagonist (meaning that it blocks narcotic drugs from having an effect on the body), is approved by the Food and Drug Administration solely to treat narcotic abuse and alcoholism. It has been suggested that this drug could also have a protective role in MS by reducing toxic, nerve-damaging substances. To date, no clinical trials have been performed to demonstrate this alleged benefit of naltrexone.

Some immune cells (known as T cells) have a damaging effect in MS while others provide protection. NeuroVax is an immune-based therapy that aims to stimulate T cells capable of suppressing the damaging T cells. NeuroVax is in very early trials and is not yet approved by the FDA.

Although naltrexone, NeuroVax and other therapies may have promise, the best medical advice is to avoid them until scientific evidence of their efficacy and safety is available.

The use of MS medications that have undergone exhaustive testing and received FDA approval is still subject to debate in the medical and scientific community. Recall the good-news/bad-news roller coaster last year involving natalizumab (Tysabri). Ready to be marketed, it turned out to be associated with a potentially fatal infection in some patients and was withdrawn.

Although they are safe, the “disease-modifying agents,” or DMAs, currently in wide use for MS are no wonder drugs. Interferon beta-1b (Betaseron), interferon beta-1a (Avonex, Rebif), glatiramer (Copaxone), and mitoxantrone (Novantrone) are only partially effective in the short term, and it is not at all clear how they work. They are expensive, have not as yet been shown to alter the disease’s progression over the long term, and can produce unpleasant side effects.

It is understandable that people with MS, frustrated by the medical community’s inability to fully explain, much less cure, their illness, may be tempted by testimonials on the Web about new and purportedly miraculous agents. Still, it is best to stick with options, however imperfect, that have been scientifically shown to be safe and effective.

– Sean J. Pittock, M.D., Neurology, Mayo Clinic, Rochester, Minn.