Drug Slows Alzheimer's Disease

Jan. 9, 2006 -- The drug Namenda slows Alzheimer's disease for at least a year, doctors report in the Archives of Neurology.

Namenda, which was approved by the FDA in 2003, had already fared well in a study that lasted about seven months. The new results come from an extension of that study.

The Alzheimer's Association estimates that 4.5 million people in the U.S. have Alzheimer's disease. Alzheimer's is the most common form of dementia in older adults. However, it's not a normal part of aging.

Alzheimer's disease affects parts of the brain involved in memory, intelligence, judgment, language, and behavior. Its exact cause isn't known, and no cure exists.

Experts' Comments

"This study demonstrates that it is possible to alleviate some of the cognitive and functional losses associated with the later stages of Alzheimer's providing a basis for greater optimism on the part of caregivers," says Barry Reisberg, MD, in a news release.

Reisberg worked on both Namenda studies. He's on staff in the psychiatry department of New York University's medical school.

"Our study verifies that this medication continues to be beneficial and is safe with remarkably few side effects," Reisberg says.

The journal also contains an editorial by Jeffrey Cummings, MD, of the David Geffen School of Medicine at the University of California at Los Angeles (UCLA).

"These new data from Reisberg and co-workers provide additional reassurance to prescribing physicians that long-term use of [Namenda] is safe, continues to have a low rate of adverse effects, and may have continuing beneficial clinical effects," writes Cummings. He didn't work on Reisberg's study.

Year-Long Study

In the original study, patients either got Namenda or a fake drug (placebo). When the study was extended for an additional six months, patients could keep taking Namenda or switch to Namenda from the placebo.

All patients had moderate to severe Alzheimer's. They took a 10-milligram dose of Namenda twice a day.

Those who had already been taking Namenda generally appeared to maintain their benefits. In patients who had previously taken the placebo, the pace of mental decline from Alzheimer's slowed significantly, the researchers report.

Results were based on a variety of tests that checked mental decline.

No new side effects were noted. The most common adverse effects were agitation, insomnia, hallucinations, urinary tract infection, and urinary incontinence.

The study was funded by Merz Pharmaceuticals GmBH, which markets Namenda in Germany.