Many drugs are associated with adverse effects on cognitive function. Those that increase the anticholinergic burden are a particular concern, and include:^8,20

• treatments for functional gastrointestinal disorders;
• antiemetics;
• anti-arrhythmic drugs (class 1a type) eg quinidine, amiodarone, procainamide or disopyramide;
• urinary frequency and incontinence drugs eg oxybutynin;
• muscle relaxants
• antispasmodics
• anticholinergics for Parkinson’s disease
• antipsychotics
• anxiolytics
• non-selective monoamine reuptake inhibitors (MAOIs) eg selegiline
• oral antihistamines

Other drugs which may impair cognitive function include steroids (glucocorticoids), opiates, benzodiazepines and non-benzodiazepine sedatives, dopaminergic drugs (eg L-dopa) and anti-epileptics.²⁰

Cognitive toxicity has also been associated with amantadine, phenytoin, digoxin, beta-blockers, and antibiotics such as penicillins, quinolones, and cephalosporins.²¹