Monday, January 6, 2014

Memantine (Namenda) for Lewy Body Dementia

Thing you should know #1: Memantine, also known by its trade name Namenda, works by blocking a receptor called NMDA (stands for N-methyl-D-aspartate). It is thought that in dementia, like Alzheimer's, over-excitation of this receptor (usually by a specific chemical glutamate which is the most important excitatory chemical in the human brain)--over-excitation of this receptor can actually lead to cell death and be a part of the process that causes dementia (neurodegeneration) to progress further. Blocking this receptor is supposed to selectively block the excitatory pathway while allowing the normal day-to-day functions of the cell to continue unabated. And the initial studies on dementia & this medication were really only done with the Alzheimer's kind of dementia.

Thing you should know #2: Namenda is only FDA approved for moderate to severe Alzheimer's disease.

Thing you should know #3: If we in the medical world waited for the FDA to catch up by approval to all that is being treated in certain ways in Medicine, we would push back the way Medicine is practiced 40 years... at least.

Thing you should know #4: There are many types of dementia. You hear about Alzheimer's all the time because it is the most common form of one category of dementia and because the media really highlights this form of dementia. But.... B12 deficiency can cause a dementia; thyroid dysfunction and depression and Obstructive Sleep Apnea can mimic dementia; large strokes or many smaller strokes can cause dementia ....on and on. And of the specific category of dementias known as NEURODEGENERATIVE DEMENTIAS, Alzheimer's is just one of them among others like Lewy Body Dementia, Frontotemporal Dementia, Semantic Dementia, Non-fluent Aphasia Dementia.....and so-on.

So, this quick article summary essentially suggests what many neurologists have already been recommending: We should be using this medication that decreases over-excitation leading to brain cell death in dementia, more broadly that just in Alzheimer's type. And, although this study summary above doesn't mention it, we should also be using the classic medication used for Alzheimer's, Aricept (donepezil) more broadly as well among the other dementias.

This study from August 2010 The Lancet Neurology, showed that over 24 weeks (half a year) of the study's duration, the patients had statistically significant improvements (over placebo), actual improvements, in overall cognition and in behavioral measures as well (since many patients understandably have behavioral issues when aspects of the brain lose their path, but other conflicting aspects remain fully capable).

In this study, complete data was a available for 159 patients, which is a pretty robust number.

But, to me, it really just confirms that we shouldn't be waiting to place our loved ones on medications, such as this, until studies are built to prove what should work based on our neurologic understanding and what we see in clinical practice.... as long as the treatment does not break our fundamental oath of "Do no harm." That being said, even that truth has shades of grey. I'm perfectly comfortable given someone a touch of stomach-nausea (harm) if I think I can delay some memory problems/behavioral problems just a bit longer, especially if that means you/your family can stay in your/their home a few months or years longer before having to transition to expense home nursing or to a nursing home.