Diphenhydramine (Benadryl)

Question 1

Class / Action

Answer 1

Antihistamine, sedative

1. Potent antihistamine agent, which possesses anticholinergic (antispasmodic), antiemetic, and sedative effects

Question 2

Onset / Duration of Action

Answer 2

IV/IO: Immediate IM: 15-30min / Duration of Action 6-8hours

Question 3

Indications

Answer 3

1. Antihistamine
   a. Anaphylaxis, use as an adjunct to epinephrine
   b. Uncomplicated allergic conditions
2. Dystonic or Extrapyramidal Reactions

Question 4

Contraindications

Answer 4

Hypersensitivity

Question 5

Precautions

Answer 5

1. Hypotension patients
2. Glaucoma
3. Chronic Asthmatic

Question 6

Dosages / Administration

Answer 6

1. ADULT: 25-50mg Deep IM or SLOW IV/IO Push; Maximum Dose 100mg
2. PED: 1-2mg/kg IM, SLOW IV/IO Push; Maximum Dose 50mg

Question 7

Adverse Reactions

Answer 7

Sedation, Sleepiness, Dizziness, Disturbed Coordination, Epigastric Distress, Dry Mouth, Thickening of Bronchial Secretions, Hypotension, Palpitations, Tachycardia, Bradycardia, Blurred Vision.