Diphenhydramine/Benadryl

Question 0

Mech of action

Answer 0

Nonspecific competitive H1/H2 antagonist>blocks histamine releasee, suppresses central cholinergic activity and inhibits reuptake and storage of dopamine, leading to prolonged action of dopamine and reduction of brochoconstriction, vasodilation, increased vascular permeability.

Question 1

Drug Classification

Answer 1

Antihistamine

Question 2

Pharmacokinetics

Answer 2

OOA-10-15min IV, 15-30min PO
Peak- 1-4hrs
Duration- 6-8hrs
H/L- 1-4hrs

Question 3

Indications

Answer 3

Allergic reaction, Anaphylaxis, Dystonic reaction

Question 4

Contraindications

Answer 4

Hypersensitivity

Question 5

Side effects

Answer 5

Sedation, dries bronchial secretions, blurred vision, HA, palpitations, dizziness, drowsiness, fatigue, euphoria, hypotension

Question 6

Dose

Answer 6

Adult- 25-50mg IV. IO, IM, PO

Pedi- 1mg/kg IV, IO, IM, PO max 50mg

Question 7

Precautions

Answer 7

Caution with patients with severe liver disease and acute asthma

Question 8

Drug-Drug

Answer 8

Potentiates sedative effects of alchohol, benzos, CNS depressants, and MAOI’s