Dementia and Memory Loss:
Q. Are there any new treatments in the pipe line for treating dementia and short-term memory loss? Specifically in the elderly.

A. Yes, there are many new agents in the pipeline, but how soon they will be ready for clinical use is not clear--that really depends on the U.S. Food & Drug Administration. The kinds of agents that are being investigated reflect the many different theories of memory loss, dementia, and Alzheimer's Disease (AD). Since most of the research has focused on AD, I will discuss that first.

Many researchers believe that AD is mainly due to the accumulation of "gunk" in the brain, called beta amyloid. Several new compounds that interfere with the formation and toxicity of beta amyloid are under investigation; e.g., droloksifen and estrogens. A vaccine that prevents formation of amyloid plaque (deposits formed from beta amyloid) , and even decreases existing plaques is now being tested in human subjects (Elan Corporation). Other researchers are focusing on the damaging role of so-called excitatory amino acids in AD, such as glutamate. Too much excitation from these naturally-occurring brain chemicals, and brain cells can literally be excited to death.

Drugs such as memantine (which is still being tested) and lamotrigine (an anti-seizure medication that is already available) are potential antidotes to this hyper-excitation. Still other researchers believe that AD results from an inflammatory process in the brain, and are testing various anti-inflammatory agents similar to Vioxx[rofecoxib], a pain reliever already on the market. In the near term, a new agent called galantamine [Reminyl] is probably going to be available soon. This has a mechanism of action similar to some agents already available for AD, such as donepizil (Aricept), which increase a critical brain chemical called acetylcholine. However, galantamine adds a second chemical action that could improve its efficacy.

Many other agents for AD are in the works, and you may want to contact the Alzheimer's Association (http://www.alz.org/) for more information. Meanwhile, a variety of cognitive enhancers are being developed that might benefit individuals with milder degrees of memory impairment; e.g., a compound with the lyrical name, SB 271046 is now in the early stage of investigation (SmithKline Beecham). Herbal agents, such as gingko biloba, are also being investigated as cognitive enhancers; however, the public should be wary about claims in the lay press about such natural remedies. Since the FDA does not monitor these over-the-counter agents, the public needs to be cautious before using them. Some may have unexpected side effects; e.g., gingko can affect blood clotting.