Drug-induced cognitive impairment

Many classes of medications, such as antipsychotics, anticonvulsants, anticholinergics, and other commonly prescribed drugs, can cause cognitive impairment (CI). The negative effect of drugs on cognitive functions is due to the following pathophysiological mechanisms: a reduction in neuronal excitability, an increase in gamma-aminobutyric acid activity, and decreases in enzyme activity, the number of receptors, cerebral perfusion, as well as brain atrophy; moreover, a number of mechanisms have not been fully studied. An important role in the development of drug-induced CI is played by predisposing (senility or childhood, brain damage, chronic diseases, functional disorders, genetic causes, initial cognitive decline, polypragmasia), and precipitating (acute diseases, infections, metabolic disorders, dehydration, acute urinary retention, malnutrition, environmental influences, etc.) factors. The dose of a drug, the duration of its use is of absolute value. There is a need for the differential diagnosis of CI induced by drugs and CI directly related to the diseases, for which these drugs are prescribed. Drug-induced CI should be suspected if an association is established between a decline of cognitive functions and the start of drug intake. The treatment of this CI involves primarily dose withdrawal or reduction and the use of sustained-release dosage forms, if available. In some cases, cognitive training and/or special drug therapy may be required to correct the CI that has occurred. The measures to prevent drug-induced KI include the choice of the lowest-risk drugs, the use of current side-effect rating scales, in particular an anticholinergic burden scale.