Dementia medicines

Key points about medicines for dementia

  • Although there's no cure for dementia, there are medicines that can help some people with forgetfulness and help them to think more clearly in earlier stages.
  • The aims of treatment are to promote independence, maintain function and improve symptoms.
  • The medicines for dementia fall into 2 categories - cholinesterase inhibitors and memantine.
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Examples include donepezil (Aricept®), rivastigmine (Exelon®) and galantamine (Reminyl®).

  • They're used mainly to help with memory and concentration for people with mild to moderate Alzheimer's disease, but may also be used for other dementias, including Lewy Body dementia.   
  • These 3 medicines are similar and generally have similar side effects. The choice of medicine is usually based on cost, formulation and side effects.
  • Only some of them are funded in Aotearoa New Zealand.
  • All the cholinesterase inhibitors are available as tablets or capsules, but rivastigmine is also available as a patch applied to the skin daily.

Common side effects 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. Don't drive if this medicine makes you drowsy (sleepy).

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

Alzheimer's disease

Medicines can't cure Alzheimer's disease, but they may slow it down for a while and make it easier to live with.

  • Cholinesterase inhibitors may be used in people with mild to moderate Alzheimer’s disease or mixed dementia. They may give temporary help with memory, motivation, concentration and daily tasks.
  • Memantine may be useful in the moderate or severe stages of Alzheimer’s disease, to help with attention and daily tasks, and may ease distressing or challenging behaviours.

However, there is no evidence to show that these medicines slow the progression of the disease. For some people they may help to improve memory and their ability to perform daily tasks, improve quality of life and reduce the need for care.¹

Lewy body dementia

Cholinesterase inhibitors can be helpful for someone with dementia with Lewy bodies who has distressing hallucinations or delusions, or who has challenging behaviours (eg, agitation or aggression).

Vascular dementia

People with vascular dementia are usually given medicines to treat the conditions that cause dementia. These include high blood pressure, high cholesterol, diabetes or heart problems. Controlling these may help slow the progression of vascular dementia. Acetylcholinesterase inhibitors may be used for people with vascular dementia only if they also have Alzheimer's disease, Parkinson's disease dementia or dementia with Lewy bodies.

Frontotemporal dementia (FTD)

There have been a few small trials of cholinesterase inhibitors and memantine in people with FTD. These have had mixed results. In some cases, these medicines made people’s symptoms worse. They're not licensed for this use and are not widely used.

It's important that the person has a firm diagnosis of Alzheimer’s disease (not another form of dementia) and the stage they're at. A specialist, such as neurologist, psychogeriatrician, geriatrician or psychiatrist, will usually be involved in the prescription of these medicines.

Dementia often causes behavioural and psychological symptoms which can be very distressing.


Depression is three to four times more common in people with dementia than in older people without dementia. Antidepressants such as citalopramsertraline or mirtazapine can be helpful in improving the symptoms of depression, including low mood or sadness, and may improve appetite and sleep problems. Usually a trial of at least 2 weeks is needed to tell how useful the medicine is going to be. If the medicine 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 aren't true (delusions), or see or hear things that aren't there (hallucinations). These symptoms can cause even more distress than the loss of memory. Medicines called antipsychotics (eg, risperidone) are sometimes used short term to treat disruptive behaviour when other measures have not been helpful.  

Antipsychotics should not be the first choice and should only be used if there is immediate risk of harm to the person or others. This is because:

  • antipsychotics may not always be able to treat or reduce the disruptive behaviour caused by dementia
  • antipsychotics can cause 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 Alzheimer's disease –treating disruptive behaviour.(external link)

The person with dementia may need support to manage their medicines. You may find it helpful to:

  • Have a routine: Ask your pharmacist if medicines are best taken at a certain time of day or with or without food. Then make a daily plan. 
  • Use pill boxes or blister packs: Ask your pharmacist about these. Read more about remembering to take your medicine.
  • Think about swallowing difficulties: If swallowing is a problem, talk to your pharmacist or doctor. Read more about difficulty swallowing medicines.
  • Consider side effects: Ask your doctor or pharmacist about any side effects that could happen and what you should do if you get them. Some 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 has been useful may not continue to be effective because of the changes to the brain caused by dementia.
  • Keep a record of all medicines: Including over-the-counter (OTC) medicines such as pain relievers, cold medicines and antacids. Also include vitamins, herbal supplements and complementary medicines. Take this record to medical appointments.

  • What medicines do you suggest, if any?
  • How long is the course of treatment?
  • How will we know if the medicine is working?
  • How will we know when to stop the medicine?
  • If one medicine does not work, is it worth trying another?
  • What side effects might I experience?
  • What other types of treatment could help?
  • Who can I call when I have a question about my treatment?

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

About dementia(external link) Alzheimer's New Zealand, NZ
How is dementia treated(external link) NHS, UK
Treatment and management of dementia(external link) Dementia Australia


  1. The pharmacological management of Alzheimer’s disease: The place of donepezil(external link) BPAC, NZ, 2010
  2. Antipsychotics in dementia: Best Practice Guide(external link) BPAC, NZ
  3. Managing patients with dementia: What is the role of antipsychotics?(external link) BPAC, NZ, 2013
  4. Treatments for dementia Alzheimer's Society(external link), UK

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Dr Joanna Wang, Old Age Psychiatrist; Angela Lambie, Pharmacist

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