Medicines used by 2m could raise risk of dementia
MEDICINES taken by up to two million Britons may increase the chance of dementia.
A study highlighted a 30 per cent higher risk from some drugs prescribed for depression, bladder problems and Parkinson’s.
The medicines – anticholinergics – have already been linked to falls, confusion and memory problems in the elderly.
The latest study found they were more likely to cause dementia if taken for at least four years. It suggests anticholinergics may have triggered around 20,000 dementia cases out of a national total of 850,000.
The researchers said their results did not prove some anticholinergics caused the illness but warned doctors should consider the effects when prescribing them.
The chance of a random individual developing dementia is roughly 10 per cent. But taking anticholinergics was found to increase the risk to 13 per cent.
Published in the British Medical Journal, the study was the largest of its kind to look at the link between the drugs and dementia.
Anticholinergics work by blocking a chemical messenger in the brain called acetylcholine, which can affect moods, movement and the bladder.
One in five people on antidepressants are prescribed anticholinergics – the most common being amitryptyline. Others include dosulepin and paroxetine.
The extra dementia risk was also found for medications prescribed for bladder conditions – such as tolterodine, oxybutynin and solifenacin and Parkinson’s drugs, such as procyclidine.
The study looked at medical records of 300,000 patients over 65, of whom 40,770 had a dementia diagnosis.
George Savva, who led the research at the University of East Anglia’s school of health sciences, said: ‘We found that people who had been diag- nosed with dementia were up to 30 per cent more likely to have been prescribed specific classes of anticholinergic medications.
‘And the association with dementia increases with greater exposure to these types of medication.’
Doug Brown of the Alzheimer’s Society, which sponsored the research, said: ‘Guidelines for doctors say that anticholinergic drugs should be avoided for frail older people because of their impact on memory and thinking, but doctors should consider these new findings for all over-65s, as long-term use could raise the risk of dementia.’
Dr Noll Campbell, a study co-author, said the results suggested doctors should
‘Should be vigilant’
prioritise alternatives to anticholinergic medications long before symptoms of dementia appear.
Chris Fox, a UEA professor and consultant psychiatrist, said: ‘While the associations are moderate, given the high incidence of dementia, they reflect a potentially important risk to patients. Doctors and patients should therefore be vigilant about using anticholinergic medications.’
Separately, the study gave a clean bill of health to antihistamines.
Previous research has suggested anticholinergics, which includes hay fever medications, could also increase the risk of dementia. But the study said there was no higher risk.