Certain drugs may impair thought process in elderly

NEW YORK (Reuters Health) - Elderly people who take anticholinergic drugs are at risk of developing intellectual deficits, even though their risk of dementia is not increased, French researchers report.

Anticholinergic drugs block the function of the neurotransmitter acetylcholine and are prescribed for a variety of conditions, which include nausea, spasms, irregular heart rhythm, allergies, asthma, pain, high blood pressure, Parkinson's disease, ulcers and certain mental disorders.

Before prescribing anticholinergic drugs to elderly patients with mild impairments, doctors should check to see if they are already taking any drugs in this class, lead investigator Dr. Karen Ritchie and colleagues advise in their report, published in the online issue of the British Medical Journal.

To evaluate the effects of anticholinergic drugs, the research team, based at Hopital La Colombiere in Montpellier, recruited patients 60 years of age or older being treated in general practices. Thirty patients had been using an anticholinergic drug for at least one year and 297 patients were not receiving anticholinergic drugs.

Testing revealed mild mental impairment in 24 (80 percent) of those using anticholinergics compared with 105 (35 percent) who were not using anticholinergics. Specifically, anticholinergic users showed significantly worse performance in simple reaction time, attention, immediate and delayed visuospatial memory, narrative recall and verbal fluency.

Upon further analysis, the researchers found that only anticholinergic drug use and age were significantly associated with mental impairment. Gender, education, untreated depression, and treated high blood pressure were not associated with mental impairment.

However, when the same subjects were followed-up eight years later, there was no difference between the groups in the rates of dementia.

Based on these findings, anticholinergic drugs should be considered as a possible cause of mild mental impairment that can be reversed, Ritchie and her team concludes.

SOURCE: British Medical Journal, Online First, February 1, 2006.