Physostigmine
Studies with the cholinesterase inhibitor physostigmine in small numbers of Alzheimer’s patients, some of which were conducted by my colleagues Drs. Yaakov Stern and Richard Mayeux, showed superior memory test performance compared to placebo. The size of the improvement was comparable to what would be shown years later with tacrine and donepezil, but physostigmine never succeeded in the same fashion for two main reasons: the very short duration of action meant that pills needed to be given five to six times daily, and it frequently caused nausea and other side effects. Given these difficulties, using physostigmine to prevent age-related memory loss was never even
entertained as a concept. A long-acting physostigmine compound with single daily dosing was developed, but this did not prove to be very effective, and physostigmine is now consigned to the dust heap of history. I feel that this is unfortunate, because several of the Alzheimer’s patients who participated in the clinical trials at our center did show some benefit.
Properties of Acetyl-l-carnitine (Alcar)
Is found in muscle and helps get energy out of fat.
Can repair damage in lymphocytes, a type of white blood cell that is essential for normal immune function.
Boosts metabolism within nerve cells, and slows the loss of nerve growth factor that helps maintain the functioning of nerve cells in the hippocampus and frontal cortex. In fact, acetyl-lcarnitine raises the levels of nerve growth factor by 30 to 40 percent in the brains of rats.
Prevents the loss of acetylcholinesterase, thereby indirectly enhancing cholinergic function.
While it remains unclear which of these many actions underlies acetyl-l-carnitine’s promemory effects, I have chosen to discuss it under the cholinesterase inhibitor class of compounds.
Promising results emerged in small numbers of patients with Alzheimer’s disease, but larger placebo-controlled trials met with failure. Other small-scale studies have shown an advantage for acetyl-l-carnitine over placebo in people with mild memory loss, but there are also several negative reports. Like other compounds in its class, there are no long-term studies to determine if it can prevent age-related memory loss.
The usual dose is 2 to 5 grams daily, and there are few side effects. You can obtain acetyl-lcarnitine in health food stores, and this is an example of how the same substance can surface as both a modern pharmaceutical compound and an alternative medication. In fact, as more and more research is conducted with various types of alternative medicines, the two fields will begin to converge and their boundaries may eventually disappear altogether.
Taken From: The Memory Program How to Prevent Memory Loss
and Enhance Memory Power
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