Pharmacology · single question
Diphenhydramine (Benadryl), a first-generation antihistamine, commonly causes which oral side effect?
Show answer and explanation
Correct answer: A. Xerostomia (dry mouth)
- A. Correct. Its anticholinergic activity reduces salivary flow, causing dry mouth.
- B. It decreases—not increases—salivation.
- C. Gingival overgrowth is linked to phenytoin, cyclosporine, and CCBs, not antihistamines.
- D. Black hairy tongue is associated with tobacco/antibiotics/poor hygiene.