Diphenhydramine

Question 1

Diphenhydramine

Class

Answer 1

Antihistamine (anticholinergic)

Question 2

Diphenhydramine

Action

Answer 2

1) H-1 receptor antagonist, that inhibits:
- arterial dilation
- capillary dilation and leakage
- bronchoconstriction
- pulmonary edema
- itching and wheals
2) Controls drug induced extra pyramidal symptoms
3) Inhibits motion sickness
4) Antitussive
5) Sedative

Question 3

Diphenhydramine

Indication

Answer 3

Anaphylaxis (after EPi- the drug of choice)
Allergic Reaction
Phenothiazine induced extra pyramidal symptoms

Question 4

Diphenhydramine

Dose/Route

Answer 4

1mg/kg SLOW IVP or deep IM up to 100mg

Question 5

Diphenhydramine

Peds dose

Answer 5

1mg/kg slow IVP, IM, IO up to 50mg

Question 6

Diphenhydramine

Onset

Answer 6

1-2 min IV, IO

10-15 min IM

Question 7

Diphenhydramine

Contra

Answer 7

Acute asthma attack

Use cautiously during pregnancy

Question 8

Diphenhydramine

Adverse effects

Answer 8

CV: h/a, confusion, vertigo, sedation
GI: n/v
EENT: pupil dilation, worsens glaucoma, dry mouth, thirst, thickens airway secretions

Question 9

Diphenhydramine

Precautions

Answer 9

Potentials effects of ETOH & CNS depressants

Question 10

Diphenhydramine

Supplied

Answer 10

50mg/ml in 1ml vial