Drugs widely used to treat Alzheimer's disease have little actual benefit, controversial research suggests.
Aricept is widely used
The National Institute for Clinical Excellence recommended in 2001 that cholinesterase inhibitors should be prescribed on the NHS.
But a five-year Lancet study by the University of Birmingham concludes that routine prescribing of the drugs is a waste of scarce resources.
Alzheimer's experts, however, have challenged the finding.
The drugs cost about £1,000 per person per year.
In total, just 565 patients with mild to moderate Alzheimer's disease took part in the study.
They were given either the cholinesterase inhibitor donepezil (Aricept) or a dummy pill.
The main aim of the study was to assess whether donepezil delayed progress of disability or the need for institutional care.
The study also looked at the optimal dose and length of treatment, and what effect donepezil has on the mood and behaviour of patients, their ability to undertake daily activities, and whether donepezil relieved the burden on carers.
Lead researcher Professor Richard Gray said: "We've known for some time that patients do better on memory tests when they take these drugs but the improvements were small and we wanted to find out whether patients got benefits that really mattered to them - for example, could they go for a walk and find their way home.
"In particular, we wanted to know whether donepezil delayed going into institutional care. If so, this alone would make the drugs worth paying for."
No significant benefits
However, donepezil did not seem to produce significant benefits for any of the criteria that the researchers examined.
Alzheimer's has been linked to low levels of acetylcholine in the brain because of degeneration of the nerve cells that produce this molecule
Cholinesterase inhibitors inhibit the enzymes responsible for breaking down acetylcholine
Patients taking the drug did do slightly better in memory tests - but the improvement was disappointingly small.
In a test asking people questions such as how to spell the word 'world' backwards, those on the drug performed only slightly better than those who were not - with a difference of less than one point on a scale of 30.
Professor Gray said: "There are a lot of people with dementia and far too little money available to look after them.
"Doctors and health-care funders need to question whether it would be better to invest in more doctors and nurses and better social support rather than routine prescription of these expensive drugs."
Concern at findings
A spokesman for NICE said a review of its recommendations on Alzheimer's drugs was currently under way, and the new study would be considered.
The results of the review are due out in May 2005.
Professor Clive Ballard, director of research at the Alzheimer's Society, said he was disappointed by the findings, and concerned they could be used to further restrict access to drugs which he believed could delay symptoms.
He said: "Over the past seven years, evidence from people with dementia and their carers has proved that cholinesterase inhibitors are effective, not as a cure for Alzheimer's, but for slowing the worsening of symptoms and improving quality of life for some people.
"It is extremely important that the results of this single trial do not lead to the withholding of important treatments for the many people with Alzheimer's disease who benefit from them."
Eisai and Pfizer UK, two companies who manufacture cholinesterase inhibitors, issued a statement stressing patients had seen benefits from the drugs.
There are over 700,000 people with dementia in the UK, of whom about 400,000 have Alzheimer's disease.