New study links Dementia to over-the-counter drugs Posted on 27 January 2015

A new US study released in the journal JAMA Internal Medicine, has linked the use of over-the-counter drugs such as those for hayfever and insomnia to Dementia. The study linked higher doses and prolonged use of drugs with an anticholinergic effect to a higher dementia risk in elderly people.

The Medicines and Healthcare Products Regulatory Agency, said it would be reviewing new evidence. Experts said that the public should not panic and stop taking medications, but Dr Doug Brown from the UK Alzheimer's Society encourages doctors and pharmacists to be aware of the potential link and to advise anyone concerned about the risks to speak to their GP before stopping medications.

All medicines can have side effects; the drugs highlighted by the study have an 'anticholinergic' effect, blocking the neurotransmitter acetylcholine. Although patient information leaflets accompanying these types of drugs carry warnings of the possibility of reduced attention span and memory problems, researchers believe there should be more warnings about the link to a higher risk of dementia.

The research carried out at the University of Washington looked at the elderly population and found the increased risk appeared when people took drugs every day for three years or more. Dr Shelly Gray and colleagues followed the health of 3,434 people aged 65 and older who had no signs of dementia before the study. By looking at medical and pharmacy records, they determined how many of those had been given drugs with an anticholinergic effect. They then looked at the doses that were prescribed and how the data compared with the subsequent diagnoses of dementia over 10 years, 797 of the participants were diagnosed with dementia. 

More research into the cognitive effects of compounds is required and the Alzheimer's society in the UK have said they are funding more research to better understand the connections between drugs and the development of dementia.

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Source: Gray S, Crane P, Dublin S, et al. Cumulative Use of Strong Anticholinergic Medications and Incident Dementia. JAMA Internal Medicine. 2015.

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