A woman fears her mother's mental health will deteriorate rapidly if plans to withdraw Alzheimer's drugs from the NHS are approved.

Chris Storey with her mother Ellen, who has Alzheimer's disease

Chris Storey, 55, said that while the medication cannot reverse the effects of dementia, they have given Ellen Storey, 83, enthusiasm for life after the effects of her condition left her listless and confused.

She is one of many carers at the Oxfordshire branch of the Alzheimer's Society fighting plans to prevent the medications Reminyl, Aricept and Excelon being prescribed by NHS doctors.

Alzheimer's disease is a degenerative condition of the brain which leads to dementia, and although the drugs are not a cure, they can slow the disease's progression.

NHS staff presently prescribe them in line with guidelines from the National Institute for Clinical Excellence (Nice) - responsible for deciding which treatments can be used by the health service.

But the agency has reversed its decision, claiming the drugs do not justify the £60m a year cost.

Miss Storey, of Reading Road, Wallingford, said: "The effects of Aricept were immediate after my Mum started taking it. It was like someone had given her back to us. It has helped her whole being and her whole personality has returned.

"It's given her enthusiasm for life and that's one of the key things, but Nice aren't measuring that. They've changed their mind purely because of cost."

Mrs Storey was prescribed Aricept 18 months ago. She moved from her London home to Wallingford to be nearer her daughter and son-in-law, Dr Mike Simmons.

Miss Storey said: "We know Aricept will never bring her memory back completely, but it slows down the rate at which it is being lost.

"Without the drugs I think she would go downhill rapidly and would need more help."

Oxfordshire members of the Alzheimer's Society are now writing letters to Nice demanding that it considers the difference the drugs have made to their lives.

Branch chairman Dr David Birch said: "I would ask everyone in Oxfordshire affected by this issue to contact Nice to tell them why these drugs are so vital for people with Alzheimer's."

Andrew Dillon, chief executive of Nice, said: "It's important to note that Nice has not yet issued final guidance on the review of drugs for the treatment of Alzheimer's disease.

"Until final guidance is issued to the NHS, the existing guidance published in 2001 continues to apply."