Drug-Induced Neurologic Conditions

Tammie Lee Demler, BS, PharmD, MBA, BCPP


US Pharmacist. 2014;39(1):47-52. 

In This Article

Cognitive Impairment and Delirium

Delirium can be a neurologic side effect of drugs, especially in (although not limited to) elderly patients. Delirium is characteristically acute in onset and precipitates fluctuations in cognition, mood, attention, and arousal. Delirium can be reversed when the underlying causative agent is identified and removed. Adverse effects can cause subtle impairment of executive functions, thereby lessening the brain's ability to regulate cognitive tasks such as working memory, problem-solving, and verbal reasoning. Increased awareness of the drugs that contribute to cognitive impairment is necessary, particularly with elderly patients.[5]

Prescribers can refer to the Beers Criteria to determine which drugs are linked to cognitive impairment (Table 2).[5] Delirium and dementia are thought to originate with altered cholinergic transmission. Anticholinergic agents are among the classes with the highest risk of precipitating confusion and cognitive impairment, and the severity increases when multiple agents with confounding risks are used together. Research indicates that the total cumulative anticholinergic effect can better predict the development of delirium than the specific drug itself. Cognitive toxicity can develop quickly, especially when the patient is not educated about this potential drug-induced effect and worsens the risk by self-medicating with OTC drugs that increase the overall burden.[5]