Usage of Drugs with Potential Adverse Effects on Cognition in a Memory-Clinic

Cognitive decline is a frequent clinical symptom in elderly patients. In particular, memory disturbances are an early sign and a risk factor for subsequent development of neurodegenerative dementia. At the same time, elderly patients often receive multiple medications due to an increasing number of acquired diseases. Certain drugs have adverse side effects on cognition due to interference with the cholinergic or GABA-ergic system. This could lead to underestimation of the actual cognitive status at initial clinical presentation. In the present study we included 221 patients (mean age 68,5 years) who presented for the first time in a specialized memory-clinic and who had or developed dementia during follow up. Most patients had mixed vascular-degenerative dementia (57%). On average, patients took 2.1 drugs. 19.9% of the patients had medications with potential adverse effects on cognition. Patients with medication affecting cognition had a worse cognitive performance than patients with a medication not influencing cognitive functioning (Mini-Mental vs. 18.8. 22.01, p=0.01) in univariate analysis. Psychotropic drugs were used less frequently (38%) than primary non-CNS medication. The results remained unchanged even after performing a case-control study with the mixed dementia population with age and gender matched patients. However, in multivariate analysis, only the absolute number of medication taken remained as an independent factor. Our data highlight the clinical importance of medication history in the diagnostic workup of cognitive impairment. The absolute number of medication taken seems to be more important than medication with possible adverse side effects on cognition.