A recent Newsweek cover story brought to light the devastating condition known as Alzheimer's disease. Are we close to a cure yet? Is there hope for the millions of Americans who suffer this fatal disease? Here's a synopsis of what medications we have and what hopes are there for the future.

It's All About Acetylcholine

Acetylcholine is the neurotransmitter in several brain pathways. Central to understanding how these medications work is that Alzheimer's disease patients lose the ability of this transmitter to work successfully or fail to produce it enough. Enzymes that are known as acetylcholinesterases are responsible for breaking down acetylcholine. Thus medications that prevent these acetylcholinesterases from degrading acetylcholine help in preventing or minimizing the effects of Alzheimer's.

Tacrine

The first acetylcholinesterase inhibitor drug approved for Alzheimer's by the Federal Drug Administration was Tacrine (Cognex). A 1994 study showed that Tacrine at high doses improve mild to moderate Alzheimer's in a 30 week clinical trial. The duration of action of Tacrine is six hours and needs to be given four times a day. Unfortunately, these doses produced quite a number of unpleasant side effects including nausea, vomiting, diarrhea and liver toxicity. Its use has now been somewhat phased out by newer agents.

Donepezil

In 1996, Donepezil (Aricept) was the second drug approved for Alzheimer's disease entering the market. Its duration of action is longer than Tacrine and needs to be only given once a day. It has fewer side effects and appears to target brain cells. It works better than Tacrine in terms of producing acetacholine and liver enzyme tests do not need to be monitored, if taking Donepezil.

If given early, both Tacrine and Donepezil still have small response rates and may improve only mild to moderate Alzheimer's disease. Currently, we cannot predict which medication will work with each patient. These drugs cannot stop the disease progression, but may delay symptoms for up to a year. A trial of about 24 to 30 weeks should be given with each drug.

Gingko Biloba

One of the most used herbal preparations in Europe is Gingko Biloba. European clinical trials suggest that Gingko Biloba extract may improve clinical symptomatology of progressive degenerative dementia. Due to the lack of stringent clinical standards in Europe compared with the U.S., many American physicians are hesitant to advocate Gingko Biloba for Alzheimer's. Hence, more trials are needed for better study of the actions of Gingko Biloba and any potential side effects.

Vitamin E and Selegiline

Free radicals in our bloodstream are thought to contribute to Alzheimer's disease; hence Vitamin E and Selegiline (Eldepryl) have been studied for their ability to scavenge free radicals from our system. Recent studies suggest its use may delay Alzheimer's symptoms by 25 percent more than the usual time period and may have some additive effects when used in conjunction with acetylcholinesterase inhibitors. Most physicians advocate Vitamin E in treating Alzheimer's (1000 IU twice daily), and more free radical scavengers are now being studied today for a similar role.

Estrogen

One of the most encouraging reports on Alzheimer's came in 1996 when the Journal of the American Geriatric Society published a report suggesting that women taking estrogen supplementation soon after menopause had considerably significant low rates of Alzheimer's when compared to the general population. It is thought that estrogen boosts production of acetylcholine and slows down the progression of amyloid plaques that are present in brain autopsies of Alzheimer's patients. Although hormone replacement is still debated among many women for its use, estrogen may be one of the first therapies that may show preventive evidence in Alzheimer's disease.

The Future

More medications are being studied today in Alzheimer's, including ones in the acetylcholinesterase inhibitor class such as Metrifonate (Promem). Other areas of study include medications that boost the production of acetylcholine, as well as genetic therapy. As our population gets increasingly older, it is imperative we find the weapons to combat this dreadful disease.

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