Drugs for the treatment of dementia

There are currently four drug treatments licensed for the treatment of Alzheimer's disease. The anticholinesterase drugs (Aricept (donepezil), Exelon (rivastigmine) and Reminyl (galantamine) are licensed for the mild to moderate stages and Ebixa (memantine) is licensed for the moderate to severe stages. None offer a cure, however for a proportion of people the drugs provide important benefits particularly to mood, alertness and confidence.

In January 2011 the National Institute for Health and Clinical Excellence (NICE) published final guidance recommending that that the anticholinesterase drug treatments should be available to people in the mild to moderate stages of Alzheimer's disease and Ebixa should be available to people in the moderate stages, if they could not tolerate the anticholinesterase drugs, and for all in the severe stages.

The Society welcome that these drugs are now available to people with Alzheimer's disease. Health bodies must now make sure that the guidance is implemented and people with Alzheimer's get access to them.

Background

Current licensed treatments

Most of the research on drugs has focused on drugs for Alzheimer's disease. There are currently four drugs for Alzheimer's licensed in the UK, and one drug licensed for the treatment of severe aggression/agitation in people with Alzheimer's disease. One of these drugs, rivastigmine is also licensed for the treatment of Parkinson's disease dementia. There are no licensed drug treatments for other forms of dementia.

Aricept (donepezil hydrochloride), Exelon (rivastigmine), Reminyl (galantamine) all belong to the same class of drug known as anticholinesterase treatments. They appear to be of most benefit to people in the early to moderate stages of dementia. A small number of studies suggest benefit may be extended beyond the moderate stages.

The drug Ebixa (memantine) was licensed in the UK in October 2002 and is the first drug for people with moderate to severe Alzheimer's disease.

None of the drugs available offer a cure for Alzheimer's disease. The current drugs can improve cognition, especially attention and planning; and for some people stabilize every day function for at least six months. They can also increase alertness, improve mood and restore confidence in some though by no means all of those who take them. The drugs relieve symptoms and although there is some emerging evidence that they affect the underlying disease process it remains controversial.

There is increasing evidence that anticholinesterase drug treatments may ameliorate some mild mood symptoms, such as anxiety, depression and apathy. However, there is no clear evidence of value in the acute treatment of agitation. There is emerging evidence that Ebixa may be of benefit in the treatment of agitation and aggression.

As part of harmonization procedures across Europe, the antipsychotic drug risperidone has been licensed for the treatment of severe aggression that is resulting in marked distress or risk and which has not responded to other treatments. The license only permits short term treatment for a maximum of 6 weeks. Alzheimer's Society believes that this is a helpful development, as risperidone has a small but important place to play in the treatment of very severe behavioural symptoms. It is also however vital to avoid widespread prescribing or prolonged prescriptions which can lead to serious adverse outcomes including stroke and death.

At present, it is impossible to predict who will benefit from an anti-dementia drug. The evidence suggests that about half of all patients will benefit from this treatment. The Society argues that the key to cost-effective, rational treatment is good monitoring.

Availability of licensed drugs

The National Institute of Health and Clinical Excellence (NICE) is the Government body responsible for assessing the cost and clinical effectiveness of drug treatments and producing guidance on which treatments should be funded by the NHS.

Guidance published in January 2011 sets out that anticholinesterase treatments should be available to people in the mild to moderate stages of Alzheimer's disease and that Epixa should be available for people in the severe stages and for people who are unable to tolerate anticholinisterase treatments.

Alzheimer's Society has warmly welcomed NICE's guidance. The Society campaigned for several years to get beter access to drug treatments for people with alzheimer's disease, after a previous guidance from NICE restricted access to these drugs.

Potential new treatments

Alzheimer's Society believes that there are several new drugs currently being investigated that are potentially exciting, such as the antihistamine drug Dimebon, the anti-amyloid treatment PBT2 and the anti-tau drug Rember. However, it is important to note that only a small number of drug treatments in clinical trials eventually become licensed treatments and it is important to fully assess the effectiveness and safety of new drugs before they are licensed and become widely available. Additionally, there is typically a five-year gap from final stages of research to a drug becoming licensed. More research funding is urgently needed to increase the number of clinical trials and to speed up the development of new drugs.

The Society campaigns for:]

• Regular reviews and monitoring of people with dementia who are prescribed medication and treatment to continue for people with dementia who show evidence of benefit

• People with dementia and their carers to have as much information as possible about the relative side-effects and possible benefits of any drug which receives a licence. The use of such drugs should also be closely monitored by clinicians, drug companies and the Department of Health to ensure that patient safety remains paramount.

• Increases in the funding for research into treatments for all forms of dementia.

• NICE guidance to be reflective of up to date evidence on the effectiveness of drug treatments.

Further information

• Drug treatments for Alzheimer's disease factsheet

• NICE guidance on drugs for Alzheimer's disease

Last updated by Chris Quince, Senior Policy Officer. April 2012.