After taking diphenhydramine (Benadryl) for an allergic reaction, a person experiences drowsiness and a dry mouth. These findings are an example of a(n):

• A. Therapeutic effect
• B. Side effect
• C. Unpredictable effect
• D. Untoward effect

Answer: (B)

This question tests understanding of drug effects beyond the intended therapeutic action. Diphenhydramine is known to cause drowsiness and dry mouth because of its sedating and anticholinergic properties. These outcomes are predictable and commonly seen with this medication, so they’re best described as side effects. They’re not the therapeutic benefit, they aren’t unusual or unpredictable, and while they can be uncomfortable, they don’t automatically constitute an untoward adverse event.