More than 23,000 elderly people with Alzheimer's could be dying prematurely in care homes each year after being given drugs to keep them quiet, a report claims today.

Anti-psychotic drugs, which are not licensed to treat dementia but are prescribed to control agitation, sleep disturbance and aggression, are being given to 100,000 elderly people to keep them "quiet and manageable", says a report by Paul Burstow, the Liberal Democrat MP and a campaigner for the rights of elderly people.

Despite studies that show the drugs can increase the risk of strokes and have other harmful side effects, the report claims the Government has failed to act to stem their use.

The report comes as research by three universities says long-term use of anti-psychotics offers "no long-term benefit for most patients".

The claims in the report will fuel the debate over the use of powerful drugs, dubbed "chemical coshes" because of their strong sedative effect, on care home residents.

Mr Burstow cited a yet-to-be published study by King's College London that gave a placebo to one group of Alzheimer's patients and anti-psychotics to another for 12 months.

The study, funded by the Alzheimer's Research Trust, found that after 24 months, the placebo group had a 78 per cent survival rate compared with 54.5 per cent for the rest; after 42 months the survival rates were 60 per cent versus 28 per cent.

Mr Burstow said: "There are around 244,000 people with dementia living in care homes, and the Alzheimer's Society estimates 100,000 are being given anti-psychotic drugs. Of those, I am saying that 23.5 per cent could be dying prematurely as a result of being prescribed anti-psychotic drugs - or 23,500 people a year."

Neil Hunt, of the Alzheimer's Society, said: "The over-prescription of anti-psychotic drugs to people with dementia is a serious abuse of human rights. Anti-psychotics should be used as a last resort."

Mr Burstow's report, which will be debated in the Commons today, calls for urgent police action and a ban on routine prescribing.

The drugs involved are thought to include Risperdal, Largactil, Serenace, and Stelazine, made by Janssen-Cilag, Sanofi-Aventis, IVAX and Goldshield respectively. None recommends the use of their drug in Alzheimer's patients.

Mr Burstow said: "Using drugs to restrain vulnerable older people with dementia is no different to strapping them to a chair. It is an abuse of their human rights. Ministers are guilty of being complacent. There should a ban on prescribing anti-psychotic drugs in all but the most severe cases of dementia."

A Department of Health spokesman said: "Guidance to health professionals and care staff is very clear: anti-psychotic drugs should only be used when they are appropriate as part of best clinical care practice."