People with Alzheimer’s disease might benefit from taking some prescription medications like a cholinesterase inhibitor. These medications do not slow down progression of Alzheimer’s but are used to treat some of the symptoms people have.

Cholinesterase inhibitors

There are three cholinesterase inhibitors available to treat Alzheimer’s:

  • donepezil (Aricept)
  • rivastigmine (Exelon)
  • galantamine (Reminyl)

All of these drugs work in a similar way. So far, research has not found a difference in how effective each drug is, but some people may respond better to one drug than another or have fewer side-effects.

Cholinesterase inhibitors are given to people with mild to moderate Alzheimer’s, and doctors will continue to prescribe one of these drugs as symptoms progress, so long as it is safe and suitable to do so.

How cholinesterase inhibitors work

In Alzheimer’s disease, nerve cells become damaged and lose their ability to communicate. Cholinesterase inhibitors work by increasing the amount of a chemical called acetylcholine, that helps messages to travel around the brain. These messages are vital to the way we move, think and remember. Cholinesterase inhibitors can reduce the symptoms of Alzheimer’s for a time.

These treatments are normally given as tablets or capsules, but they are available in a liquid form too. Donepezil is also available as a tablet that dissolves on the tongue, and Rivastigmine is available in patches, where the drug is absorbed through the skin. Your doctor will discuss the most suitable form for you.

Effects of cholinesterase inhibitors

People with Alzheimer’s may find that their symptoms improve by taking a cholinesterase inhibitor. This could be improvement in thinking, memory, communication or with day-to-day activities. Others may find that their condition stays the same, or that their symptoms do not worsen as quickly as they would have expected. Some people may not notice any effect at all.

As these drugs don’t stop the disease from progressing in the brain, symptoms will continue to get worse over time. However, they can help some people to function slightly better than they would do without the drug.

The most common side-effects of cholinesterase inhibitors are feeling or being sick, diarrhoea, having trouble sleeping, muscle cramps and tiredness. These effects are often mild and usually only temporary. Not everyone will experience side-effects. If you are worried about side-effects you can talk about this with your doctor.


Memantine (Ebixa or Axura) is recommended as an option for people with moderate or severe Alzheimer’s disease, and for people with moderate Alzheimer’s if cholinesterase inhibitors are not suitable. Memantine is normally given as a tablet, but it is also available as a liquid.  Your doctor will discuss the most suitable form for you. Like cholinesterase inhibitors, memantine is not a cure. However, it can help with some symptoms.

Memantine is currently only recommended for people with Alzheimer’s disease, and people with dementia with Lewy bodies if cholinesterase inhibitors are not effective. Research is underway to learn more about whether it might be beneficial for people with other forms of dementia.

People with moderate or severe Alzheimer’s disease are sometimes offered combination therapy, where a cholinesterase inhibitor is given in addition to memantine.

How memantine works

Memantine also helps nerve cells in the brain communicate with each other. It does this by regulating a chemical called glutamate in the brain. In Alzheimer’s disease this can allow brain cells to work more effectively for longer, and it can help to reduce the symptoms of Alzheimer’s disease for a while.

Effects of memantine

Some people taking memantine may not notice any effect at all. Others may find that their symptoms stay the same when they would have expected them to get worse.

Some people experience side-effects when taking memantine. The most common side-effects of memantine are headaches, dizziness, drowsiness and constipation. These are usually only temporary, and if you are concerned about them you can talk to your doctor.


Treatments for dementia

Read more about treatments for dementia, including information on treating depression, anxiety and agitation and for information on antipsychotics.

What is Alzheimer's disease?

Find out more about the symptoms and causes of Alzheimer's disease, and the treatments currently available.


Order health information

Alzheimer’s Research UK has a wide range of information about dementia. Order booklets or download them from our online form.

This information was updated in May 2020 and is due for review in May 2022. It does not replace any advice that doctors, pharmacists or nurses may give you. Please contact us if you would like a version with references.

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