I previously posted an analysis of a double blind study where Namenda, a medicine for Alzheimer’s, showed benefit for fibromyalgia pain. In the previous study from Spain, Namenda was significantly better than a placebo for treating Fibromyalgia. But only a minority of patients improved. As importantly, it took a six-month’s long trial of treatment before the benefit from Namenda compared to placebo was statistically significant.
After reviewing that data, I had mixed feelings about recommending memantine for my patients. (I will now call Namenda “memantine,” the generic version which is much less expensive.) Since then I’ve recommended memantine to five FMS patients. In a bow to reality, I suggested they try memantine for a two-month trial period, instead of the six months used in the double-blind study. The results; two patients improved meaningfully. One could not tolerate raising the dose. Two followed through but memantine did not help.
Now I’m writing to alert you to an encouraging study where memantine helped a very different kind of pain, the chronic pain that can occur from a mastectomy among women treated for breast cancer. (There have been no further studies on memantine and fibro.) After mastectomy, 30% or more of women develop a burning or shooting pain in the chest, arm and armpit that lasts for three months or more. In a single blind study, 20 women received memantine for two weeks before and two weeks after their mastectomy. Twenty other women who had a mastectomy took a placebo.
After three months, the women rated the intensity of their pain on a scale of zero to ten. The results: Women who had taken memantine experienced substantially less pain than did the women who took placebo. The p value was 0.017. (Less than .05 is “significant”.) Memantine also reduced the need for prescription pain medicines. Only one of 20 women who had taken memantine needed a prescription compared to six of 20 women who had taken placebo. (Six months post operation memantine patients still had less pain, but the difference was no longer statistically significant.)
Memantine is probably useful for some forms of pain. But we should keep in mind it might react differently for different forms of pain. Post-mastectomy pain results from obvious trauma to peripheral nerves. FM reflects abnormalities in the brain and the spine that are not classically “traumatic.” Since we have only one controlled study for memantine and fibromyalgia, anecdotal experience might be our next most useful resource.
Some scientists doubt that anecdotes are useful. As a practicing physician, I strongly disagree. Anecdotal experiences can and should influence our judgments—especially if we can create a mechanism through which many, many individuals can share their experience. The Internet has become such a mechanism. Our challenge: how to adapt this mechanism to the practical needs of clinicians, researchers and patients who care about Fibromyalgia, Chronic Fatigue Syndrome and related health problems.
Two key questions: Who has the skill and the interest to create a practically useful forum on line? Who has the interest and ability to organize and/or provide the necessary funding?
Please feel free to comment especially if you have taken memantine for any type of pain.