Somnolence, confusion, dizziness especially in the elderly. Delirium. Use with caution in the elderly, CVD, increased intraocular pressure, asthma, GI obstruction, urinary retention, thyroid dysfunction.

• A. Cardiovascular effects
• B. Pregnancy effects
• C. Adverse effects
• D. Benadryl adverse effects

Answer: (D)

The main point is how first-generation antihistamines cause anticholinergic and CNS depressant effects, which is reflected in Benadryl’s adverse effects. Diphenhydramine (Benadryl) can cross into the brain and also block muscarinic receptors, leading to somnolence and cognitive issues. In older adults, these anticholinergic effects readily cause delirium, confusion, and dizziness, with even greater risk for falls and functional decline. The list of cautions—elderly, cardiovascular disease, increased intraocular pressure, asthma, GI obstruction, urinary retention, thyroid dysfunction—all line up with anticholinergic burden, since these conditions can be worsened by drying of secretions, impaired detrusor function, or increased eye pressure. So the description fits the adverse effects profile of Benadryl, rather than pregnancy risks or broader cardiovascular concerns.