Alzheimer’s disease , which is the leading cause of dementia in people older than 65, affects more than 4 million people in the United States. This progressive, degenerative disease of the brain leads to memory loss, impaired thinking, and personality change.

Alzheimer’s disease can take a pleasant, independent person and, over time, make him or her irritable, incapable of sound judgment, and unable to dress or feed themselves. The toll of Alzheimer’s disease is often as great on a caregiver as it is on the person with the condition.

There are drugs on the market to treat Alzheimer’s disease, but these are all intended for patients with mild to moderate disease and have only a modest effect.

In the April 3, 2003 issue of the New England Journal of Medicine , researchers reported on a drug called memantine, which blocks the activity of glutamate. Glutamate is a brain chemical which, when present in abundance, causes the stimulation and subsequent damage or death of nerve cells in the brain. It has been implicated in the progression of Alzheimer’s disease.

The scientists report that memantine reduces the rate of cognitive and functional decline in patients with moderate to severe Alzheimer’s disease. This is the first drug that has been shown to slow the course of decline in patients in the later stages of the disease. As such, it may turn out to have important implications for Alzheimer’s patients, as well as the people who care for them.

About the Study

The researchers enrolled 252 patients with moderate to severe Alzheimer’s disease. The patients were at least 50 years old and were not institutionalized.

126 patients were randomized to receive 10 milligrams of memantine twice a day for 28 weeks; the other 126 received a similar looking placebo pill twice a day. Neither the patients nor the researchers knew which pill the patients were taking.

The study subjects went through a battery of behavioral, cognitive, and functional tests at the beginning and end of the study. The main tests were:

  • The Clinician’s Interview-Based Impression of Change Plus Caregiver Input (CIBIC-Plus) test, which took interviews with both patients and their caregivers into account when measuring cognition, function, and behavior
  • The Alzheimer’s Disease Cooperative Study Activities of Daily Living Inventory modified for severe dementia (ADCS-ADLsev), in which caregivers assessed a patient’s ability to perform activities of daily living

The researchers compared the change in scores on these tests at the beginning and end of the study for the treatment and control groups. 72% of the participants completed the study.

The Findings

Compared to controls, the patients taking memantine showed significantly less decline on the CIBIC-Plus and ADCS-ADLsev tests at the end of the study. In practical terms, this translated into the memantine group having fewer difficulties putting on clothing, bathing and using the toilet, and maintaining continence.

The treatment group also scored significantly better in:

  • Cognitive performance such as social interaction, memory, language, visual orientation, and attention
  • Speech, ambulation, and other motor skills
  • Time required of caregivers

Although a majority of patients in the study experienced adverse effects, most were mild to moderate in severity and were either unrelated or unlikely to be related to the memantine.

How Does This Affect You?

This study suggests that memantine may slow cognitive, functional, and behavioral deterioration in patients with moderate to severe Alzheimer’s disease, a group of patients for which there has been no effective treatment. The significant results of this study stem not just from test scores, but also from interviews with patient caregivers, showing that this drug has a measurable benefit in a real-world setting.

Additional research is needed to show if memantine will slow progression of Alzheimer’s disease for more than six months, if it will be effective for treating milder forms of the disease, and if it will enhance effects of other medications.