Dementia Treatment for Alzheimer's Disease

Most of the medicines currently approved by the U.S. Food and Drug Administration (FDA) for Alzheimer's disease fall into a category called cholinesterase inhibitors. These medicines slow the breakdown of the neurotransmitter acetylcholine, which is reduced in the brains of people with Alzheimer's disease. Acetylcholine is important for the formation of memories and it is used in the hippocampus and the cerebral cortex, two brain regions that are affected by Alzheimer's disease.

 

There are currently four cholinesterase inhibitors approved for use in the United States, which include:

 

• Tacrine (Cognex^®)
• Donepezil (Aricept^®)
• Rivastigmine (Exelon^®)
• Galantamine (Razadyne^®).

 

These Alzheimer's disease medications temporarily improve or stabilize memory and thinking skills in some individuals. Many studies have shown that cholinesterase inhibitors help to slow the decline in mental functions associated with Alzheimer's disease, and that they can help reduce behavioral problems and improve the ability to perform everyday tasks. However, none of these drugs can stop or reverse the course of Alzheimer's disease.

 

A fifth drug, memantine (Namenda^®), is also approved for use in the United States. Unlike other drugs for Alzheimer's disease, which affect acetylcholine levels, memantine works by regulating the activity of a neurotransmitter called glutamate that plays a role in learning and memory. Glutamate activity is often disrupted in people with Alzheimer's disease. Because this drug works differently from cholinesterase inhibitors, combining memantine with other Alzheimer's disease drugs may be more effective than any single therapy. One controlled clinical trial found that patients receiving donepezil plus memantine had better cognition and other functions than patients receiving donepezil alone.

 

Doctors may also prescribe other drugs, such as anticonvulsants, sedatives, and antidepressants, to treat seizures, depression, agitation, sleep disorders, and other specific problems that can be associated with dementia.

 

In 2005, research showed that use of "atypical" antipsychotic drugs such as olanzapine (Zyprexa^®) and risperidone (Risperdal^®) to treat behavioral problems in elderly people with dementia was associated with an elevated risk of death in these patients. Most of the deaths were caused by heart problems or infections. The FDA has issued a public health advisory to alert patients and their caregivers to this safety issue.