Standard treatment for Alzheimer's has been limited mainly to either cholinesterase inhibitors (CIs) such as donepezil (Aricept) and galantamine (Razadyne), or another drug, called memantine (Namenda). CIs and memantine regulate different brain chemicals, which are important to memory. Taken separately they slow the progression of the disease in only about 10 to 20 percent of patients, and even then only modestly.
But the new study, published in the journal Alzheimer Disease and Associated Disorders, found that over the course of three years the combination therapy, on average, cut the rate of decline in half compared with a CI alone. And the longer the patients took the drugs, the more dramatic the benefits.
"The combination won't cure the disease," said Alireza Atri, M.D., Ph.D., lead author of the study and a memory disorders specialist at Massachusetts General Hospital. "But if you want the best chance of preserving as much cognitive and functional ability as you can, my advice for patients with Alzheimer's disease is to get on combination therapy and stay on it until we have more powerful treatments." Experts not involved in the study agree. "I've been treating people with Alzheimer's since the 1980s," Kennedy says. "Now I routinely have patients on a CI and memantine, and I think they're doing much better."
If you're considering the drugs for yourself or someone you care for, remember that even the combination won't reverse the disease, just slow its progression. They're also expensive, ranging from about $1,700 to $2,600 a year per drug. Side effects can include constipation, diarrhea, and headache, but they're usually mild. Our consultants think it makes sense to try the drugs for a year or more under the scrutiny of a doctor and family members.
Researchers hope that other drugs being tested in clinical trials may go further to actually reverse cognitive decline. For example, in a study published in the July 19, 2008, issue of the journal Lancet, 183 people with Alzheimer's were given a placebo or an antihistamine used in Russia, called Dimebon, which might also help prevent the death of nerve cells. After six months, those on the drug showed improved cognition, function, and behavior. The most common side effects were dry mouth and depression. For information about enrolling in a trial of the drug, go to www.clinicaltrials.gov.