How is Alzheimer’s Disease Treated?
Alzheimer’s disease is a complex disease, and no single “magic bullet” is likely to prevent or cure it. That’s why current treatments focus on several different issues, including helping people maintain mental function, managing behavioral symptoms, and slowing Alzheimer’s disease.
Alzheimer’s disease research has developed to a point where scientists can look beyond treating symptoms to think about delaying or preventing Alzheimer’s disease by addressing the underlying disease process. Scientists are looking at many possible interventions, including treatments for heart disease and Type 2 diabetes, immunization therapy, cognitive training, changes in diet, and physical activity.
What drugs are currently available to treat Alzheimer’s disease?
No treatment has been proven to stop Alzheimer’s disease. The U.S. Food and Drug Administration has approved four drugs to treat Alzheimer’s disease. For people with mild or moderate Alzheimer’s disease, donepezil (Aricept®), rivastigmine (Exelon®), or galantamine (Razadyne®) may help maintain cognitive abilities and help control certain behavioral symptoms for a few months to a few years. Donepezil can be used for severe Alzheimer’s disease as well. Another drug, memantine (Namenda®), is used to treat moderate to severe Alzheimer’s disease. However, these drugs don’t stop or reverse Alzheimer’s disease and appear to help patients only for months to a few years.
These drugs work by regulating neurotransmitters, the chemicals that transmit messages between neurons. They may help maintain thinking, memory, and speaking skills and may help with certain behavioral problems.
Other medicines may ease the behavioral symptoms of Alzheimer’s disease: sleeplessness, agitation, wandering, anxiety, anger, and depression. Treating these symptoms often makes patients more comfortable and makes their care easier for caregivers.
No published study directly compares the four approved Alzheimer’s disease drugs. Because they work in a similar way, it is not expected that switching from one of these drugs to another will produce significantly different results. However, an Alzheimer’s disease patient may respond better to one drug than another.
What potential new treatments are being researched?
NIA, part of the National Institutes of Health, is the federal agency for Alzheimer’s disease research. NIA-supported scientists are testing a number of drugs and other interventions to see if they prevent Alzheimer’s disease, slow the disease, or help reduce symptoms.
Scientists are very interested in the toxic effects of beta-amyloid–a part of amyloid precursor protein found in deposits (plaques) in the brains of people with Alzheimer’s disease. Studies have moved forward to the point that researchers are carrying out preliminary tests in humans aimed at removing beta-amyloid, halting its formation, or breaking down early formation before it can become harmful. For example, in a clinical trial sponsored by NIA, scientists are testing whether “passive” immunization with an FDA-approved drug called IGIV can successfully treat people with Alzheimer’s.
The aging process
Some age-related changes may worsen Alzheimer’s disease damage in the brain. Researchers think that inflammation may play a role in Alzheimer’s disease. Studies have suggested that common nonsteroidal anti-inflammatory drugs (NSAIDs) might help slow the progression of Alzheimer’s disease, but clinical trials so far have not shown a benefit from these drugs. Researchers are continuing to look at how other NSAIDs might affect the development or progression of Alzheimer’s disease.
Scientists are also looking at free radicals, which are oxygen or nitrogen molecules that combine easily with other molecules. The production of free radicals can damage nerve cells. The discovery that beta-amyloid generates free radicals in some Alzheimer’s disease plaques is a potentially significant finding in the quest to understand Alzheimer’s disease.
Heart disease and diabetes
Research has begun to tease out relationships between Alzheimer’s disease and vascular diseases, which affect the body’s blood vessels. Some scientists have found that some chronic conditions that affect the vascular system, such as heart disease and diabetes, have been tied to declines in cognitive function or increased Alzheimer’s disease risk. Several clinical trials are studying whether treatments for these diseases can improve memory and thinking skills in people with Alzheimer’s disease or mild cognitive impairment.
A number of studies suggest that factors such as a healthy diet, exercise, and social engagement may be related to the risk of cognitive decline and Alzheimer’s disease. For example, emerging evidence suggests that physical activity might be good for our brains as well as our hearts and waistlines. Some studies in older people have shown that higher levels of exercise are associated with a reduced risk of Alzheimer’s disease. Clinical trials are underway to study the relationship of exercise to healthy brain aging and the development of Alzheimer’s disease.
Scientists have also studied whether diet may help preserve cognitive function or reduce Alzheimer’s disease risk. Some studies have found that the “Mediterranean diet” is associated with a reduced risk of Alzheimer’s disease. To confirm the results, scientists are conducting clinical trials to examine the relationship between specific dietary components and cognitive function and Alzheimer’s disease.
Studies are looking into many other possible treatments, including hormones and cognitive training, to see if they might improve thinking skills in people with Alzheimer’s disease or even prevent Alzheimer’s disease in people who are at risk.
What are clinical trials?
People who want to help scientists test possible treatments may be able to take part in clinical trials, which are research studies that test the safety, side effects, or effectiveness of a medication or other intervention in humans. Study volunteers help scientists learn about the brain in healthy aging as well as what happens in Alzheimer’s disease. Results of Alzheimer’s disease clinical trials are used to improve prevention and treatment approaches.