An 82-year-old woman with Alzheimer’s dementia is experiencing dry mouth, constipation, and falls. Which medicine is most important to review given these side effects?

• A. Oxybutynin
• B. Amlodipine
• C. Donepezil
• D. Cetirizine

Answer: (A)

Anticholinergic burden in older adults often shows up as dry mouth, constipation, blurred vision, confusion, and an increased risk of falls. In this scenario, the most important drug to review is the one with the strongest antimuscarinic (anticholinergic) effect. Oxybutynin fits that description because it is a potent anticholinergic used for overactive bladder, and in an 82-year-old with Alzheimer’s dementia these effects are particularly problematic. Continuing oxybutynin would worsen dryness and constipation and raise the risk of delirium and falls, so it should be prioritized for review and likely substitution or discontinuation.

Amlodipine’s main concerns are related to blood pressure and edema, not anticholinergic symptoms. Donepezil increases acetylcholine and can cause GI upset and bradycardia, but it does not produce the same anticholinergic burden as oxybutynin. Cetirizine can cause dry mouth but generally has a milder anticholinergic profile and a lower impact on constipation and fall risk than oxybutynin.