Anticholinergic serum levels and cognitive performance

Integrity of central cholinergic neurotransmission is essential for adequate cognitive functioning. Many psychotherapeutic medications have anticholinergic side-effects. In order to determine the impact of circulating anticholinergic activity on cognitive performance, 28 geropsychiatric inpatients underwent cognitive testing at different levels of anticholinergic serum activity. In 10 subjects with a diagnosis of probable Alzheimer's disease, significant deterioration of selected cognitive functions was observed at anticholinergic serum levels that caused no dysfunction in the 18 non-demented subjects. The data suggest that non-demented elderly patients with psychiatric problems tolerate psychotropic pharmacotherapy without significant negative impact on their cognitive competency. By contrast, patients with Alzheimer's disease are at risk of additional impairment. The introduction of anticholinergic serum activity as a monitoring technique for safe psychopharmacotherapy in geriatric patients is discussed.