DIPHENHYDRAMINE

Question 1

Diphenhydramine

Amount Carried

Answer 1

50 mg

Question 2

Diphenhydramine

Concentration

Answer 2

50 mg/ mL vial

Optional 50 mg oral

Question 3

Diphenhydramine

Indications

Answer 3

Anaphylaxis;

Phenothiazine reactions;

Antiemetic

Question 4

Diphenhydramine

Class

Answer 4

Antihistamine

Question 5

Diphenhydramine

Mechanism of Action

Answer 5

Blocks histamine receptor sites;

Anticholinergic

Question 6

Diphenhydramine

Effects

Answer 6

Decreased capillary permeability;

Decrease in vasodilation;

Prevents bronchospasm

Question 7

Diphenhydramine

Dose/Route

Answer 7

Anaphylaxis: 25-50 mg deep IM or IV/IO

Question 8

Diphenhydramine

Side Effects

Answer 8

Hypotension;

arrhythmias;

thickening of bronchial secretions, wheezing;

nasal stuffiness;

Sedation;

visual disturbances;

seizures

Children:

In children, may cause paradoxical CNS excitation, seizures, palpitations, thickening of bronchial secretions

Question 9

Diphenhydramine

Notes on Administration

Answer 9

Additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc.)

MAO inhibitors prolong and intensify anticholinergic (drying) effects