Drugs widely prescribed to the elderly could be responsible for a decline in cognitive and physical function, according to research from the University of East Anglia and the Regenstrief Institute.

A new report reveals that anticholinergic drugs — which are used to treat conditions including asthma, high blood pressure, insomnia, dizziness and diarrhea — could impact physical functions in elderly patients such as eating and getting dressed.

Up to half the UK’s elderly population are prescribed at least one medication with anticholinergic properties. Other anti-cholinergic drugs are also sold over the counter without the need for a prescription.

These medications affect the brain by blocking a key neurotransmitter called acetylcholine. But they have been associated with side effects including dizziness, sedation, confusion, delirium, constipation and blurred vision.

Previous studies have shown a link between these drugs and cognitive impairment, but this study is the first to summarise evidence of a physical decline among the elderly.

The research team looked at 46 studies from around the world that included 60,944 patients who had taken anti-cholinergic medications for up to 10 years.

“This is the first research to show a significant decline in physical, as well as cognitive, function. This means patients could become less and less able to carry out everyday activities like walking around, feeding themselves, washing and getting dressed,” said lead researcher Dr Chris Fox, from UEA’s Norwich Medical School. “This is likely due to the direct effect on cholinergic neurons compounded by an increase in the blood-brain permeability.

“Further studies are also needed to establish whether the cognitive decline is definitely induced by these medications — or the whether the diseases for which they are prescribed are a factor too.”