A DRUG used to treat nursing home patients suffering from dementia is making their condition worse, according to research carried out in the region.

Researchers found quetiapine, also known as Seroquel, a common treatment for agitation in people with illnesses such as Alzheimer's, affected their higher brain functions, making them worse.

Anti-psychotic drugs are used in up to 45 per cent of nursing homes to help with agitation, a common symptom of dementia.

The research team was led by Professor Clive Ballard, now of King's College, London, who began the study while he was at Newcastle University.

The British Medical Journal said the team found that when given a placebo as treatment for these symptoms, patients showed little change.

But those patients given the anti-psychotic drug quetiapine showed a deterioration of higher brain functions (cognitive decline).

The study's authors said this was particularly significant because quetiapine had been regarded as one of the safer of the anti-psychotic drugs available.

Researchers looked at 93 patients with dementia in care facilities in Newcastle.

Those in the study taking quetiapine experienced a doubling in cognitive decline compared with those who had been given placebos.

Those taking another anti-psychotic drug in the trial, rivastigmine, showed little or no worsening of their illness -and no improvement in symptoms above the placebo group.

The study highlights concerns regarding the safety of quetiapine and suggests it should not be an alternative to other medications.

The authors said in their conclusion: "Quetiapine and rivastigmine seemed of no benefit in patients with dementia and agitation in institutional care, and quetiapine was associated with greater cognitive decline than the placebo.

"Our results suggest that quetiapine should not be used as an alternative treatment to risperidone or olanzapine in people with dementia, and highlight concerns regarding the long-term use of anti-psychotics in these patients."

Alzheimer's Research Trust chief executive Rebecca Wood said: "These results show the huge and pressing need to develop new and safe treatments for people with dementia. Research into Alzheimer's is severely under-funded and we desperately need to do more to accelerate progress towards finding a cure."

AstraZeneca, which markets Seroquel, contests the claims. A spokesman said the company remained confident of the drug's safety and effectiveness.

AstraZeneca said that more than eight million people have used the drug since 1997