First-generation Alzheimer’s drugs offer limited benefits in delaying effects

The first generation of drugs to treat Alzheimer’s disease can help delay some of the disease’s effects. But the medicines don’t offer the kinds of miracles that both patients and their loved ones hope for.

Many times, the improvements that treatments can make in someone’s life are noticeable only to the family members who know the person best, says Dr. Mark Snowden, acting assistant professor of psychiatry and behavioral sciences. Snowden is medical director of Geriatric Psychiatry Services at Harborview Medical Center.

Snowden predicts that the second generation of Alzheimer’s medicines will prove more effective. He compares the situation to the first generation of medicines to battle AIDS: they helped, but not nearly as much as the second generation. A number of promising treatments for Alzheimer’s are under study.

That’s good, because Alzheimer’s is destructive. It tears away at the person’s mind and coordination.

Donepezil, whose brand name is Aricept, helps improve cognitive abilities of Alzheimer’s sufferers by about 5 percent, according to one in-depth study. That represents a slowing of the eventual deterioration.

“Families, who are doing most of the work in taking care of Alzheimer’s patients, seem to know that their relative is doing better, and is easier to take care of. That really matters a lot to them. But they still have to accept that their relative is getting worse,” Snowden says.

Here’s why scientists think that Donepezil helps: Alzheimer’s disease attacks the nerves that secrete acetylcholine as they communicate with each other, so victims of the disease have less acetylcholine than normal. Donepezil blocks activity of an enzyme that breaks down acetylcholine. By inhibiting activity of that enzyme, the drug allows patients to keep acetylcholine that would otherwise be destroyed.

Not everything that may help is a prescription medicine. One study found that large doses of Vitamin E - 1,000 IUs a day - delayed functional deterioration in many patients. Vitamin E is an antioxidant, meaning it protects brain cells from dying.

Another study found that people who took 40 milligrams of the herb ginkgo biloba, three times a day, showed better thinking ability. Caregivers reported the people were easier to take care of. The herb is apparently “neuroprotective,” as Snowden puts it.

That information about Vitamin E and ginkgo biloba is based on single studies; more studies are needed to show if those results can be repeated.

One interesting note is that doctors themselves often did not notice a difference in the people who were taking the active drugs. The differences were subtle enough that the doctors might not notice them, but caregivers did. The message here, Snowden says, is that doctors should not rely on their own observations to measure a medicine’s effectiveness: they need to consider what caregivers, who have more exposure to the patient, are seeing.

There are other medications used to treat people with Alzheimer’s. Many people with Alzheimer’s develop psychiatric symptoms. Some will develop a psychosis, involving paranoia, hallucinations and other problems. In later stages of the disease, it’s not uncommon for someone with Alzheimer’s to think that a familiar person, such as a spouse, has been replaced with an imposter. There are medications that try to help people with these symptoms, though they are not always as effective as the medicines when used on people with schizophrenia and other mental problems. ¶

Walter Neary