Concern that anticholinergic drugs could potentially worsen cognition in those with Parkinson’s disease are unfounded, according to new research reported in the Journal of Parkinson’s Disease.

Older adults commonly take the medications to treat bladder dysfunction, mood and pain, and many of the drugs are available without a prescription. Some recent evidence has shown an increased risk of dementia — in particular Alzheimer’s disease — in those regularly using anticholinergics, but research by David J. Burn, M.D., and colleagues determined that the cognitive performance of those with Parkinson’s disease who took the medications did not differ from those who did not.

“This is the first study to explore an association between anticholinergic burden and mild cognitive impairment in [Parkinson’s] participants, and is timely given recent research demonstrating cumulative anticholinergic burden and risk of [Alzheimer’s] in the general population,” Burn, director of the Institute of Neuroscience and professor of movement disorder neurology at Newcastle University in England, said in a statement. The drug burden index is used to measure older adults’ level of exposure to anticholinergic medications and the effects of that exposure on their physical and cognitive function.

The investigators studied 195 people with Parkinson’s disease and 84 people who served as control subjects. They found no differences between the two groups with respect to global cognition or assessments of attention, memory and executive function when the study period ended at 18 months. The proportion of mild cognitive impairment was similar in those who did and did not use anticholinergic drugs. Although a greater proportion of study participants with Parkinson’s disease were taking anticholinergic medications, the total drug burden did not differ between the them and the control subjects.