Donepezil treatment for Alzheimer’s dementia
What is donepezil?
Donepezil is a medication that has been licensed for the treatment of Alzheimer’s dementia. This medication was developed by the drug company Eisai and marketed with another drug company Pfizer. The drug received a licence for use in the UK in 1997 and is marketed under the trade name Aricept. A number of other companies have now started to manufacture donepezil under there are a variety of trade names besides Aricept.
How does it work?
Donepezil is a type of medication called a cholinesterase inhibitor. In Alzheimer’s dementia there are reduced amounts of a chemical called acetylcholine. This chemical is responsible for memory and learning. Donepezil increase the amount of acetylcholine by stopping it being broken down by another chemical called acetylcholinesterase.
How will the doctor decide if a person is suitable to take donepezil?
There will usually have to be a confirmed diagnosis of Alzheimer’s dementia. The doctor will check to see if there are heart problems and a heart tracing (ECG) will be arranged. People with severe breathing problems (severe asthma or emphysema) or stomach ulcers may not be suitable for donepezil.
What are the side effects?
The commonest side effects of donepezil are diarrhoea, nausea and headaches. Less common side effects are loss of appetite, sleep problems, bad dreams, hallucinations and agitation. There are rare serious effects such as fits. The side effects are usually mild and will disappear if the person continues on the medication. Occasionally the side effects are severe and the person will need to stop the medication and get medical advice. Alternate medications such as galantamine, rivastigmine or memantine may be considered by the doctor if a person cannot tolerate donepezil.
What benefit does donepezil provide?
Donepezil slows down the progression of the memory and thinking difficulties of Alzheimer’s dementia. This medication may help agitation, anxiety and delusions (false beliefs) and hallucinations (seeing or hearing things which are not there). Some people report improvements in memory and concentration. Donepezil cannot cure Alzheimer’s dementia.
How is donepezil taken?
Donepezil comes in a in a 5 mg and 10 mg tablet. The tablet can also be obtained in a form that dissolves on the tongue and this may be useful for people with swallowing problems. The tablet is usually taken at night and this can be with or after food. Some people may prefer taking the tablet in the morning since donepezil can cause sleep problems particularly when taken at night.
The 5 mg dose is prescribed for 1 month and then increased to 10 mg if the person tolerates the medication. Some people remain on 5 mgs since the 10 mg dose may have more side effects.
How long is donepezil taken for?
Donepezil is licenced for use in the mild and moderated stages of Alzheimer’s dementia. However there is evidence that even in the severe stages there may be some benefit. The doctor will continue prescribing the medication as long as there is thought to be clinical benefit. Sometimes donepezil is stopped and memantine is started in the severe stage: a combination of these medications may also be used.