This site is intended for health professionals only

Commonly used medicines linked to dementia risk

Healthcare professionals have been warned that the usage of regular over-the-counter treatments can be linked to dementia.

Drugs that have an anticholinergic effect, such as hay fever and insomnia treatments may cause an increase in the chances of dementia if used over a prolonged period of time.

A US study in JAMA Internal Medicine Journal looked at the usage of the drug in the elderly and found the increased risk appeared when people took the drugs every day for three years or more.

Dr Shelly Gray and colleagues from the University of Washington followed the health of 3,434 people aged 65 and older who had no signs of dementia at the start of the study.

They looked at medical records to determine how many of the people had been given a drug with an anticholinergic effect, at what dose and how often and compared this data with subsequent dementia diagnoses over the next decade.

The most commonly used anticholinergic-type drugs were medicines for treating depression, antihistamines for allergies such as hay fever or to aid sleep/promote drowsiness, and drugs to treat urinary incontinence. Nearly a fifth were drugs that had been bought over the counter.

During the course of the study, 797 of the participants developed dementia.

Dr Doug Brown, from the UK's Alzheimer's Society, said: "There have been concerns that regular use by older people of certain medications with anticholinergic effects, such as sleep aids and hay-fever treatments, can increase the risk of dementia in certain circumstances, which this study supports.

"However, it is still unclear whether this is the case and if so, whether the effects seen are a result of long-term use or several episodes of short-term use. More robust research is needed to understand what the potential dangers are, and if some drugs are more likely to have this effect than others.”