Expert

Do Alzheimer’s Medications Really Help?

Christiana Care Health System
Sunday, September 1, 2013
Close-up of someone holding assorted pills.

This article explores the pros and cons of the currently approved medications for Alzheimer's disease.

More than 80 medications are currently being investigated for use in the treatment of Alzheimer's disease. Patients, families, and clinicians are eagerly awaiting the availability of agents that will more effectively control the symptoms of this most common of dementias. Even more exciting, doctors hope for medications that will halt the progress of cognitive decline or even reverse the destructive process that impedes cognitive functions and ultimately kills brain cells.

While clinicians await the arrival of new treatments, they currently have access to two classes of medications approved by the Food and Drug Administration (FDA) for the treatment of Alzheimer's disease. These widely used medications have sparked controversy between those who consider them valuable treatment tools and those who regard them as hazardous and costly. Let’s look at the pros and cons of these medications from an evidence-based, yet practical viewpoint. The FDA approved “cognitive enhancers” fall into two classes.

Cholinesterase Inhibitors

Donepezil (Aricept), rivastigmine (Exelon), and galantamine (Razadyne) are inhibitors of the enzyme acetylcholinesterase. They work by diminishing the brain’s normal breakdown of the neurotransmitter called acetylcholine, an important player in the transformation of thought and experience into retrievable memories—a miracle so familiar to us that we may take it for granted unless we have seen the chaos that results from its disruption.  Each of these medications is available generically. Although this limits their cost, the associated copayments under some insurance plans can pose a significant burden.

Donepezil and rivastigmine have been approved for mild, moderate, and severe Alzheimer’s disease. Galantamine is approved for mild and moderate stages of the disease. Donepezil is also available in a new and relatively higher dose pill, and rivastigmine is the only one yet available in a skin patch delivery system, suitable for use by patients more amenable to a patch than a pill, or unable to tolerate the gastrointestinal side effects of this class of drugs. These medications share several other side effects that can be clinically significant: disruption of sleep, enhanced risk for bleeding, and slowing of the heart rate to the point of potential danger from fainting or disrupted heart rhythm.

Memantine

The other class of cognitive enhancers approved for Alzheimer's treatment contains one lonely member, memantine (Namenda). Memantine’s unique mechanism of action involves enhancement of the brain’s sensitivity to an important excitatory amino acid neurotransmitter, glutamate. Glutamate plays a key role in uniting the brain cells that must collaborate to form a specific memory. Glutamate also plays a more sinister role in the brain, contributing to the neuron-destroying process called apoptosis (programmed cell death). Memantine is approved for middle and late stages of Alzheimer's disease and is often combined with a cholinesterase inhibitor once a patient passes beyond the early stage. Memantine’s side effects are often minimal, though occasionally it can enhance or initiate confusion, agitation, constipation, or headache. 

Pros and Cons

The effectiveness of these medications appears to be modest but significant for a large number of patients who can tolerate their side effects. At their best, the cognitive enhancers slow down for six months or more the encroachment of Alzheimer's disease on multiple areas of functioning. These medications have been shown to facilitate thinking, to improve performance of activities of daily living, to contribute to the management of some non-cognitive behavioral disturbances, and to reduce the burden of caregiving by perhaps an hour a day.

Critics of these medications point out that, on average, their effect differs from that of placebo (inert medication) by only a few points on scales that include many points. They also criticize the potential of the cholinesterase inhibitors to induce distressing side effects such as severe diarrhea or fainting. A practical approach to the use of these medications requires periodic reassessment of their side effects and benefits.

Many clinicians believe that the cognitive enhancers continue to play a useful role late into the course of Alzheimer's disease. They cite studies showing that significant clinical deterioration can occur even after discontinuation during a late stage of the dementia. In some cases, however, it is appropriate to discontinue these medications, particularly when side effects have exceeded tolerability or the patient’s functional decline has progressed to a very severe stage. Side effects will diminish quickly after discontinuation, but clinical benefits will also dissipate as few as six weeks after they are stopped. Except when abrupt discontinuation is medically necessary, it is advisable to taper the cholinesterase inhibitors and memantine rather than stop them suddenly.

Summary

The outstanding efforts of many researchers have made clear that medications are only one part of the successful care of patients with Alzheimer's disease. Education of the patient and family, support of caregivers, attentive medical assessment to reduce additional sources of distress, use of resources such as adult day care programs, and behavioral assessments and interventions each contribute to the successful care of individuals suffering from dementia. In time, there is every reason to hope for medications of great effectiveness to enhance our other treatment elements. Until then, the currently available cognitive enhancers continue to play a useful role in optimizing care.

Downloads

The information provided here is a public service of the BrightFocus Foundation and should not in any way substitute for personalized advice of a qualified healthcare professional; it is not intended to constitute medical advice. Please consult your physician for personalized medical advice. BrightFocus Foundation does not endorse any medical product or therapy. All medications and supplements should only be taken under medical supervision. Also, although we make every effort to keep the medical information on our website updated, we cannot guarantee that the posted information reflects the most up-to-date research.

These articles do not imply an endorsement of BrightFocus by the author or their institution, nor do they imply an endorsement of the institution or author by BrightFocus. 

Some of the content may be adapted from other sources, which will be clearly identified within the article. 

Don't miss out.
Receive research updates, inspiring stories, and expert advice
I want to stay informed about:
Please select at least one.
You must select at least one disease category.

More Like This

  • toiletries
    Expert

    Helpful Tips for Assisting Your Loved One with Personal Hygiene

    As a caregiver, you may sometimes wonder if there is a better way to assist with their personal hygiene and grooming. As your loved one’s ability to independently manage his or her personal hygiene declines, increasingly you need to help accomplish these tasks. This article provides tips to make the process simpler and more comfortable.

    Tuesday, June 21, 2016
  • Son comforting his elderly father
    Expert

    Is It Alzheimer’s?

    This article explores the normal symptoms associated with cognitive aging, and symptoms that are more severe and could be indicative of Alzheimer’s disease or other forms of dementia.

    Monday, July 18, 2016
  • Amyloid PET Scan
    Expert

    Amyloid PET Scans: Are They a Game-Changer?

    Amyloid PET scans allow, for the first time, accurate detection of amyloid plaques—one of the hallmarks of Alzheimer’s disease—in living people. The scans may help clinicians proceed with greater knowledge and assurance, and patients will be able to have greater confidence in their diagnoses and treatment recommendations. This article explains what PET scans are and how they are currently used, and provides an update on a new clinical trial that will deliver important information on how the scans will be used in the future.

    Thursday, June 30, 2016