Alzheimer's medications provide symptomatic improvement

November 1, 2010

Many of the estimated 5.1 million Americans with Alzheimer's disease also have other serious medical conditions

MANY OF THE estimated 5.1 million Americans with Alzheimer's disease also have other serious medical conditions, and their memory impairment limits their ability to manage these conditions effectively, leading to an increase in costs.

For example, in 2006, Medicare beneficiaries with diabetes plus Alzheimer's or another dementia had average annual costs of $20,655, compared to $12,979 for those with diabetes but without Alzheimer's.

In addition, the FDA has approved Namenda (memantine), which uses a different mechanism. It is an N-methyl-D-aspartate (NMDA) receptor antagonist, and it appears to play a protective role in the brain by regulating the chemical glutamate.

"The acetylcholinesterase inhibitors and the NMDA-receptor antagonist have produced modest but apparently persistent improvements in cognition, activities of daily living and behavior in patients with disease severity ranging from mild to severe," says Mark Abramowicz, MD, editor-in-chief of The Medical Letter on Drugs and Therapeutics, a non-profit newsletter that critically appraises drugs. "Among the acetylcholinesterase inhibitors, the rivastigmine patch causes fewer gastrointestinal side effects and may be easier to administer in demented patients."

A physician will only prescribe one of the acetylcholinesterase inhibitors, since they have similar pharmacological activities, according to Ronald C. Petersen, MD, director of the Mayo Alzheimer's Disease Research Center.

"If the patient continues to progress, as most of them do, and the level of functional impairment increases, then you might add memantine, because it has a different mode of action, so the two processes can be additive," he says. "There is an increased benefit by combining them, but a modest one."

While available drugs can produce some limited symptomatic improvement, none of these agents have been shown to stop or reverse the underlying neurodegenerative process, according to Dr. Abramowicz.

Typically, these medications produce improvements in attention, concentration, memory, motivation and initiative, which is significant.

"While we use these medications all the time, they don't really change the overall duration or outcome of the disease," says Dr. Petersen.