How It Works
Cholinesterase inhibitors increase the
level of a brain chemical called acetylcholine. People with
Alzheimer's disease and related conditions have
decreased brain levels of this neurotransmitter. Increasing the amount of
acetylcholine appears to slow mental decline in people with Alzheimer's
These medicines help the brain cells work better but do
not stop or reverse the destruction of brain cells and loss of acetylcholine
that occur in Alzheimer's disease. They do not prevent the disease from getting
worse but may slow the progression of symptoms.
Why It Is Used
Cholinesterase inhibitors may be
used to treat some symptoms of Alzheimer's disease. They also may be used in
other types of
dementia, such as
dementia with Lewy bodies and
How Well It Works
Cholinesterase inhibitors may
produce small improvements in memory and general ability to function.1 For example, the person may be able to remember friends'
names better and be able to dress himself or herself with less
Cholinesterase inhibitors do not help everyone who has
Alzheimer's disease. It is believed that as the disease progresses, the
medicine eventually may stop working.
The various cholinesterase
inhibitors have similar effects on memory and cognitive function, so the choice
between medicines may be based on side effects, dosing schedules and ease of
use, individual response to a particular medicine, or other factors.
In general, most people seem to
tolerate cholinesterase inhibitors very well. The most common side effects
Less common side effects include insomnia, fatigue, and
muscle cramps. Side effects tend to be mild and usually go away within a few
weeks after treatment with the medicine is started.
Reference for a full list of side effects. (Drug Reference is not available in
What To Think About
Cholinesterase inhibitors do not
work for everyone who has Alzheimer's disease, but they are helpful for some
people. They may be a reasonable option for those who understand the risks and
costs and feel the possible benefits are worth it.
Most studies of
cholinesterase inhibitors for people with Alzheimer's disease found that the
benefits of taking these medicines are small.2, 3
Side effects seem to be milder and occur less
often with donepezil or galantamine than with rivastigmine.
Experts agree that reducing problems with memory loss may help people
with Alzheimer's disease live better. In some cases, reducing these problems
may help people live more independently for a longer period of time.
Rivastigmine (Exelon) can now be given through a skin patch. Skin
patches release medicine into the blood at a steady level and may reduce side
effects. And when a person uses a skin patch, it’s easier for caregivers to make sure the person is getting his or her
Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.
Warner J, et al. (2010). Dementia, search date
April 2008. Online version of BMJ Clinical Evidence: http://www.clinicalevidence.com.
Kaduszkiewicz H, et al. (2005). Cholinesterase
inhibitors for patients with Alzheimer's disease: Systematic review of
randomised clinical trials. BMJ, 331(7512): 321-327.
Raina P, et al. (2008). Effectiveness of
cholinesterase inhibitors and memantine for treating dementia: Evidence review
for a clinical practice guideline. Annals of Internal Medicine, 148(5): 379-397.