MASSACHUSETTS GENERAL HOSPITAL

Department of Pharmacy

Department of Nursing

Critical Care

Generic Name: Diphenhydramine
Trade Name: Benadryl
Action: Antihistamine
Indications: Urticaria
Dystonias
Nausea / Vomiting
Anxiety, Insomnia
Anaphylaxis
Administration Guidelines:
Usual Dosage Range and Route: Single dose: 25 - 50 mg IVP repeated every 4 - 6 hours

24 hour cumulative dose: 400 mg

Special Considerations: - Diphenhydramine cannot be given subcutaneously; give either iv or deep intramuscular injection

- For extravasation, refer to MGH nursing procedure manual

- Caution: will potentiate actions and side effects of narcotics and other cns depressants

Precautions and Side Effects:

- CNS depression

- Use with caution in the elderly:

- Tachycardia

- Hallucinations, blurred vision

- Nasal congestion, dry mouth

 

revised 09/03