•  Alzheimer's Disease

Ten years ago, the only thing doctors could give patients with Alzheimer's disease was their sympathy and support. Today, they can also offer real hope. There's still no cure for Alzheimer's, but new medications can slow down the disease and improve the lives of many patients. Other promising treatments are just over the horizon.

Here's a look at the most common treatments for Alzheimer's, along with new areas of research. Several of the drugs discussed below -- Razadyne, Aricept, and Exelon -- are cholinesterase inhibitors, designed to improve memory and reasoning by influencing chemical processes in the brain. Although the changes may be subtle, it's thought that these drugs can slow the deterioration of memory in many patients -- especially if they are used early in the disease process. An earlier Alzheimer's drug, tacrine (Cognex), had the potential to harm the liver and is rarely prescribed today.

Approved by the Food and Drug Administration in 2001, Razadyne (formerly called Reminyl), is one of the newest treatments for Alzheimer's disease. Like the next two drugs on this list, Razadyne works by protecting the brain's supply of acetylcholine, a chemical that carries messages between brain cells. (It does this in part by halting the activity of an enzyme with the formidable name of acetylcholinesterase, which slows the breakdown of the message-carrying acetylcholine.) Unlike other drugs, Razadyne also seems to increase the production of acetylcholine and makes brain cells more receptive to the chemical.

How it's thought to help: Studies show that many patients with Alzheimer's who take Razadyne can enjoy modest gains in their memory or thinking skills. The drug may also temporarily help put the brakes on the disease. In a 2004 study of 285 patients with Alzheimer’s and dementia, those taking galantamine showed improvement in cognition at 6 months and significant improvement at 12 months. In a placebo group who switched to galantamine, cognitive function also improved, but not to the level attained by patients who had been treated with the drug for the entire 12 months.

How it's taken: Razadyne comes in both liquid and tablet form. Most patients start at a dose of 4 milligrams twice daily. Over the next eight weeks, the dose is slowly increased to either 8 or 12 milligrams or more twice daily.

Side effects: Razadyne appears to be a very safe drug. It often causes mild side effects, including upset stomach, vomiting, diarrhea, and dizziness. Patients can help protect their stomachs by taking the drug with meals and drinking six to eight glasses of water every day.

Approved in 2000, Exelon works by enhancing acetylcholine in the brain.

How it's thought to help: In clinical trials, Exelon slightly increased the memory and thinking skills of some patients with mild to moderate Alzheimer's disease. Unfortunately, more than half of all patients showed no improvement.

How it's taken: Exelon is available as a capsule or a liquid. Most patients start at a small dose such as 1.5 milligrams per day. Over the next two weeks, the dosage then gradually increases to somewhere between 6 and 12 milligrams each day. The gradual increase in dosage helps lower the risk of side effects.

Side effects: Possible side effects of Exelon include nausea, vomiting, loss of appetite, and weight loss. Side effects are more common at higher doses.

Approved in 1996, this close relative of Exelon and Razadyne is still commonly prescribed to patients with mild to moderate Alzheimer's. In 2006 the Food and Drug Administration approved Aricept for severe Alzheimer's, making it the first drug to be approved for the treatment of all stages of the disease.

How it's thought to help: Like Exelon, Aricept has been shown to slightly boost the thinking and memory skills of some patients. Fewer than half of all patients show any improvement.

How it's taken: Most people start with one 5-milligram tablet every day. If there aren't any side effects, the dose can be upped to 10 milligrams each day.

Side effects: Patients taking Aricept often notice mild side effects such as nausea, diarrhea, and vomiting. Other possible side effects include insomnia, muscle cramps, fatigue, and loss of appetite. These problems usually fade over time even if the patient stays on the same dose.

This drug, which was approved by the Food and Drug Administration on October 17, 2003, is the first medication that has been shown to help people with severe Alzheimer's disease. It appears to work by restoring the brain's balance of glutamate, a chemical that plays a key role in memory and learning. The FDA recommends memantine for moderate to severe Alzheimer's. How it's thought to help: In a six-month study published in the New England Journal of Medicine, memantine significantly slowed the progression of advanced Alzheimer's disease. Patients who took the drug continued to get worse day by day, but their decline was about half as severe as normal. A separate study found that patients with mild to moderate Alzheimer's disease didn't see any improvement when they added memantine to their current treatments.

How it's taken: Memantine comes in pill form. In the New England Journal of Medicine study, patients took 20 mg pills every day.

Side effects: As reported in the newspaper of the American Medical Association, memantine doesn't appear to cause any significant side effects. However, the consumer watchdog group Public Citizen notes that the manufacturer has received adverse event reports from Germany that include seizures and circulatory failure.

Supplements

A simple vitamin may seem out of place on this list, but in some studies vitamin E has shown promise in Alzheimer's therapy in recent years.

Preliminary research indicates the vitamin may help protect brain cells from damage caused by Alzheimer's. A study of 341 patients with moderate Alzheimer's published in the New England Journal of Medicine found that vitamin E apparently slowed the advance of the disease. For some patients, the vitamin seemed to increase the amount of time they could live on their own. For others, it delayed the progression from moderate to advanced Alzheimer's. Vitamin E works by preventing future damage; it doesn't improve memory or provide any other immediate benefits.

"Because of its low cost and safety, [vitamin E] is recommended in addition to a cholinesterase inhibitor for the treatment of AD," according to a recent article on dementia in the journal Medical Clinics of North America.

How it's taken: Nobody knows what dosage of vitamin E works best for people with Alzheimer's. Some doctors prescribe 400 to 800 or more international units twice each day.

Side effects: Most people can take low doses of vitamin E without any problems. However, the vitamin can clash with blood thinners such as Coumadin (warfarin). Vitamin E can also heighten the blood-thinning effects of other supplements and medications such as aspirin and gingko. Talk with your doctor before using vitamin E.

Most people have heard of gingko's being touted as a memory enhancer, although a recent study in the Journal of the American Medical Association showed that gingko was not beneficial in improving memory among the group of 203 people studied. However, several earlier studies have shown some improvement in Alzheimer's disease or a slowing down of symptoms.

In one such study, published in Neuropsychobiology, a case-control study of people with mild to moderately severe Alzheimer's treated with ginkgo biloba showed a positive change in cognitive and social functioning. However, researchers observed improvement in the group of patients with mild to very mild impairment, whereas gingko served mainly to slow down or stabilize mental deterioration in people with more severe dementia.

Gingko appears to have antioxidant properties, which some researchers speculate can help prevent oxidative damage to brain cells; it also appears to have anti-inflammatory and blood-thinning properties, according to the Alzheimer's Disease Education & Referral Foundation. Because research on gingko's benefits to Alzheimer's patients is not conclusive, the National Institutes of Health is conducting a larger study on gingko biloba to evaluate its possible benefits for Alzheimer's patients.

Side effects: Like garlic and vitamin E, gingko biloba can cause increased bleeding if you are also taking a blood thinner such as warfarin. Always consult your doctor before taking gingko.

-- Chris Woolston, MS, is a health and medical writer with a master's degree in biology. He is a contributing editor at Consumer Health Interactive, and was a staff writer at Hippocrates, a magazine for physicians. His reporting on occupational health earned him an award from the Northern California chapter of the Society of Professional Journalists.

References

First published September 25, 2003
Last updated March 11, 2008
Copyright © 2003 Consumer Health Interactive

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