Study: Memantine Slows Deterioration in Alzheimer's Patients

A drug that quashes the activity of a key brain chemical is the first effective treatment for patients in the later stages of Alzheimer's disease, according to a study reported in the April 3 issue of the New England Journal of Medicine.

The drug, memantine, slows the mental and physical deterioration of patients with moderate to severe Alzheimer's disease, according to Dr. Barry Reisberg, professor of psychiatry at the New York University School of Medicine.

Reisberg led a 28-week study that compared memantine with a placebo in 252 people with moderate-to-severe Alzheimer's disease.

Currently, no treatments are available to slow the later stages of Alzheimer's disease when patients begin to lose the ability to care for themselves and the burdens on caregivers intensify.

Reisberg and his colleagues found that memantine appeared to be beneficial in terms of activities of daily living and other measures. Memantine was also not associated with a significant frequency of adverse events.

"These patients seem to be declining much less, about half as much as ordinarily expected, over a six-month period," says Dr. Reisberg. "This medication will slow down the otherwise inexorable progress of this disease, and it is remarkably free of side effects."

What is yet unknown, according to Reisberg, is whether memantine can slow the disease for more than six months. He added that the drug also may also be effective in milder forms of the disease and in combination with other medicines.

Memantine works by blocking the activity of a brain chemical called glutamate, which excites neurons. When neurons become over stimulated because of an abundance of glutamate, the nerve cells can become damaged or die.

Reisberg said nerve cells that respond to glutamate are involved in memory and learning. "Memantine is a completely different chemical way of getting at the disease," he added.

In the United States, available treatments for Alzheimer's in the mild to moderate stages are aimed at a different chemical system in the brain, according to Reisberg.

Memantine is manufactured by Merz Pharmaceuticals, based in Frankfurt, Germany. The drug has recently been approved by European regulatory authorities to treat severe Alzheimer's disease.

In the United States, Forrest Pharmaceuticals, Inc., based in New York City, has licensed the drug from Merz. The Food and Drug Administration, which has not approved the drug for marketing in the United States, is currently reviewing the drug.

Other sources: New England Journal of Medicine, New York Univesity Medical Center