Can I give Benadryl (Diphenhydramine)?

Diphenhydramine (Benadryl) Administration Guidelines

Diphenhydramine can be given to adults and children over 12 years at a dose of 25-50 mg every 4-6 hours, with a maximum of 6 doses in 24 hours, and to children 6-12 years at 25 mg per dose, but should not be used in children under 6 years of age. 1

Approved Uses and Dosing

• Diphenhydramine is a first-generation antihistamine primarily used to treat allergic reactions including anaphylaxis, urticaria, and allergic rhinitis 2
• For adults and children over 12 years: 25-50 mg (10-20 mL) every 4-6 hours 1
• For children 6-12 years: 25 mg (10 mL) every 4-6 hours 1
• Do not use in children under 6 years of age 1
• Maximum of 6 doses in 24 hours for all age groups 1

Contraindications and Precautions

• Do not use to make a child sleepy 1
• Do not use with any other product containing diphenhydramine, even topical formulations 1
• Use with caution in patients with:
  • Breathing problems such as chronic bronchitis 1
  • Glaucoma 1
  • Urinary retention due to enlarged prostate 1
  • Patients taking sedatives or tranquilizers 1

Side Effects and Safety Concerns

• Marked drowsiness is common and may impair ability to drive or operate machinery 1
• Anticholinergic effects may cause better control of rhinorrhea compared to second-generation antihistamines, but also lead to more side effects 3
• First-generation antihistamines like diphenhydramine have significant sedative and anticholinergic effects 3
• Avoid alcohol, sedatives, and tranquilizers while taking diphenhydramine as they may increase drowsiness 1
• Excitability may occur, especially in children 1

Special Populations

• Pregnant or breastfeeding women should consult a healthcare professional before use 1
• Older adults with pre-existing comorbid conditions (prostatic hypertrophy, elevated intraocular pressure, cognitive impairment) are at higher risk for side effects 3

Clinical Considerations

• Second-generation antihistamines are generally preferred over diphenhydramine due to fewer side effects 4
• For anaphylaxis management, diphenhydramine can be administered at 1-2 mg/kg or 25-50 mg/dose parenterally 3
• In combination with ranitidine, diphenhydramine is superior to diphenhydramine alone for anaphylaxis management 3

Overdose Management

• In case of overdose, contact Poison Control Center immediately (1-800-222-1222) 1
• Diphenhydramine overdose presents with anticholinergic toxicity affecting multiple organ systems 5
• For children under 6 years who ingest at least 7.5 mg/kg, refer to emergency department 6
• For patients 6 years and older who ingest at least 7.5 mg/kg or 300 mg (whichever is less), refer to emergency department 6

Alternative Considerations

• The American Academy of Sleep Medicine does not recommend diphenhydramine for treating insomnia due to minimal efficacy 3
• Second-generation antihistamines are widely available, affordable, and have fewer undesirable side effects 4

Remember to keep diphenhydramine out of reach of children and use only as directed by a healthcare professional.