Medicines for dementia

Easy-to-read information about medicines for dementia

Although there is no cure for dementia, there are medicines that can help some people with the symptoms of forgetfulness and improve their ability to think more clearly in earlier stages. The aims of treatment are to promote independence, maintain function and improve symptoms. They work by enhancing the levels of a chemical in the brain, called acetylcholine, that is involved in memory and judgment. The medicines fall into 2 categories - cholinesterase inhibitors and memantine. On this page you will find information about:

Cholinesterase inhibitors

Examples include donepezil (Aricept®), rivastigmine (Exelon®) and galantamine (Reminyl®).

  • They are used mainly for the cognitive symptoms (such as problems with memory and concentration) of mild to moderate Alzheimer's disease, but may also be prescribed for other dementias, including Lewy Body dementia.   
  • These 3 medicines are similarly effective in treating the symptoms of Alzheimer’s disease, and generally have similar side effects. There is no evidence that one medication is better than the other. The choice of medication is usually based on cost, formulation and side effects.
  • Only some of cholinesterase inhibitors are funded in New Zealand, so cost is an important factor in choosing a cholinesterase inhibitor.
  • All the cholinesterase inhibitors are available as tablets or capsules, but rivastigmine is also available as a patch that is applied to the skin daily.

Common side effects of cholinesterase inhibitors include nausea (feeling sick), diarrhoea (runny poos), vomiting (being sick), tummy pain, weight loss, loss of appetite, headache, dizziness and feeling faint. If the medicine is started at a low dose and increased slowly, this may lessen the chance of side effects. Talk to your doctor if these symptoms occur so your dose can be reviewed. If you feel faint or notice a skin rash, or are vomiting, contact your doctor. Do not drive if this medicine causes drowsiness.


Memantine (Ebixa®) is used to treat moderate to severe Alzheimer's disease. It is usually used if cholinesterase inhibitors are not tolerated or not able to be used (contraindicated). It has similar effects to the acetylcholinesterase inhibitors. It is available as a tablet and is currently not funded in New Zealand. Common side effects of memantine are flu-like symptoms (such as headaches and muscle pain),  dizziness and constipation. Do not drive if this medicine causes drowsiness.

Do medicines for dementia work?

Medicines can't cure Alzheimer's disease, but they can slow it down for a while and make it easier to live with. Cholinesterase inhibitors and memantine may improve symptoms related to cognition (understanding) and behaviour – they may relieve symptoms such as having trouble thinking and remembering things. However, there is no evidence to show that they slow the underlying progression of the disease. For some people with Alzheimer’s disease, this may mean that they have improved memory and ability to perform daily tasks, improved quality of life and reduced need for care.¹

Medicines for depression and disruptive behaviour 


Depression is three to four times more common in people with dementia than in older people without dementia. Antidepressants such as citalopramsertraline or mirtazapine may be considered and can be very helpful in improving the symptoms of sadness, and may improve appetite and sleep problems. Usually a trial of at least two weeks treatment is necessary to tell how useful the medication is going to be. If the medication is not working it should be stopped, and if it causes side effects, it may need to be changed.

Disruptive behaviour

People with Alzheimer’s disease and other forms of dementia can become restless, aggressive or disruptive. They may believe things that are not true, or see or hear things that are not there. These symptoms can cause even more distress than the loss of memory. Medicines called antipsychotics (for example, risperidone) are sometimes used short term to treat disruptive behaviour, when other measures have not been helpful.  

Antipsychotics should not be the first choice for treatment and are used as a last resort if there is immediate risk of harm to the patient or others. This is because:

  • antipsychotics don’t help much – studies have compared these medicines to sugar pills or placebos, and have found that antipsychotics usually don’t reduce disruptive behaviour in older dementia patients 
  • antipsychotics can cause serious side effects such as drowsiness and confusion (which can reduce social contact and mental skills, and increase falls), shaking or tremors (which can be permanent) and sudden death. 

Read more about treating disruptive behaviour in people with dementia Choosing Wisely, NZ

Tips for taking medicines for dementia

The person with dementia may need support to manage their medications. You may find it helpful to do the following:

  • Develop a routine for giving the medication: ask the pharmacist if medications should be taken at a certain time of day or with our without food. Then create a daily ritual. This might involve taking medications with breakfast or right before bed.
  • Pill boxes or blister packs: ask your pharmacist about aids to help you to give medication as prescribed, eg, using pill boxes or blister packs. Read more about remembering to take your medicine.
  • Swallowing difficulties: if swallowing is a problem, talk to your pharmacist or doctor. Read more about difficulty swallowing medicines.
  • Side effects: ask your doctor or pharmacist about what side effects might occur with the medication and what you should do if you get them. Some dementia medicines may make the symptoms worse, so it's important to be aware of this and let your doctor know. Read more about medicines and side effects.
  • Get the treatment reviewed regularly: a medicine which is useful may not continue to be effective indefinitely because of the progressive changes to the brain caused by dementia.
  • Keep a record of all medications, including over-the-counter (OTC) medicines such as pain relievers, cold medicines and antacids. Also include creams or eye ointments, vitamins, herbal supplements and complementary medicines. Take this record to medical appointments.

Learn more

The following links have more information on medicines for dementia. Be aware that websites from other countries may contain information that differs from New Zealand recommendations.

11 ways to get someone with dementia to take medication DailyCaring, US 
About dementia
Alzheimer's New Zealand, NZ
How is dementia treated NHS, UK
Drug treatments & dementia Alzheimer's Australia
Diagnosis, treatment and care for people with dementia: A consumer companion guide to the Clinical Practice Guidelines and Principles of Care for People with dementia NHMRC Partnership Centre for Dealing with Cognitive and Related Functional Decline in Older People. Australia 2016 
Managing Alzheimer's – behavioral symptoms Alzheimer's Association, US


  1. The pharmacological management of Alzheimer’s disease: The place of donepezil BPAC, NZ, 2010
  2. Antipsychotics in dementia: Best Practice Guide BPAC, NZ
  3. Managing patients with dementia: What is the role of antipsychotics? BPAC, NZ, 2013
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 25 Mar 2019