Study: Donepezil Appears to Protect Brains of Alzheimer's Patients

The drug donepezil (Aricept®) appears to have a protective effect on the brains of patients with mild to moderate Alzheimer's disease, according to a study reported in the November 1 issue of the American Journal of Psychiatry.

The researchers found that donepezil, a cholinesterase inhibitor, slows the progression of the disease by reducing deterioration in the hippocampus region of the brain. This region is critical to memory function and is affected earliest in Alzheimer's disease.

Donepezil is one of four drugs approved by the U.S. Food and Drug Administration for the treatment of mild to moderate Alzheimer's disease. Study author Dr. Ranga Krishnan, chief of psychiatry at Duke University Medical Center, said the findings suggest that something can be done to change the progression of this disease.

"When someone has Alzheimer's disease, the brain begins to deteriorate as the gray matter shrinks and the disease progresses," Krishnan said. "We are unsure of why and how donepezil slowed the loss of hippocampal volume, but we think the drug may help to improve cognition by increasing levels of (the chemical) N-acetylaspartate in he brain, at least temporarily."

The study involved 67 patients aged 50 and older with a diagnosis of mild to moderate Alzheimer's disease. Patients were given one of two identical pills -- either donepezil or a placebo -- each evening for 24 weeks.

The researchers found that the hippocamal volume of those in the placebo group decreased by 8.2 percent, compared to only a 0.4 percent descrease in the donepezil group. Those taking donepezil also had significantly greater improvements in cognition relative to those taking the placebo.

The researchers stressed the limitations of their study, saying additional placebo-controlled studies with larger numbers of patients are necessary to confirm and expand their findings.

Other sources: Duke University Medical Center