Which medication is explicitly listed as potentially inappropriate for older adults in the Beers Criteria?

• A. First generation antihistamines
• B. Nitrofurantoin
• C. Insulin
• D. Growth hormone

Answer: (A)

Beers Criteria targets medications that pose greater risks for older adults, often due to anticholinergic effects and its impact on cognition and function. First generation antihistamines are singled out because they strongly block muscarinic receptors and cross into the brain. In older patients, this leads to confusion, delirium, daytime drowsiness, and an increased risk of falls, along with dry mouth, constipation, and urinary retention. Because of these risks, they are explicitly discouraged in older adults, with safer alternatives preferred—such as second-generation antihistamines that have less anticholinergic activity and fewer central nervous system effects.

The other options don’t carry the same explicit PIM designation in the Beers Criteria. Nitrofurantoin has specific cautions mainly related to kidney function and duration of use; insulin and growth hormone are not flagged as explicit inappropriate choices by Beers in general, though they require careful management in older adults. The key idea is the strong anticholinergic burden of the first-generation antihistamines and the heightened vulnerability of the elderly to such effects.