← Drug quick-reference

Diphenhydramine

Brand: Benadryl

Antihistamine (1st-gen)Used for: Allergies, sleep aid (sedating)Respiratory & Allergy

Common side effects

  • Drowsiness
  • Dry mouth
  • Dizziness
  • Constipation
  • Blurred vision

Key interactions & cautions

  • Alcohol increases sedation
  • Adds to other sedating drugs
  • Adds to other anticholinergic drugs

Counseling points

  • May cause marked drowsiness
  • Do not drive until you know its effect
  • Avoid alcohol
  • Use caution in older adults
  • Avoid with narrow-angle glaucoma
← CetirizineFexofenadine →

High-yield study aid for exam prep — not a substitute for the package insert or a pharmacist’s dispensing reference.