Benadryl Flashcards
1
Q
Action
A
- Binds to histamine receptor sites, blocking H1 and H2 receptors.
- H1 causes bronchoconstriction, airway swelling, and vasodilation.
- H2 causes secretion of gastric acid.
- Does not prevent histamine release
2
Q
Onset
A
15- 30 min
3
Q
Duration
A
6- 12 hours
4
Q
Indications
A
Allergic Reaction/ Anaphylaxis (S-122, S-162)
- mild & acute allergic reactions or anaphylaxis
Poisoning/ OD (S-134, S-165)
- extrapyramidal reactions
5
Q
Dosage/Route
A
ADULT:
50mg slow IV/IM
PEDS:
PDC IM/IV
6
Q
Contraindications
A
None
7
Q
Side Effects
A
- Drowsiness / sedation (excitement in children)
- Dry mouth / thickened bronchial secretions
- Hypotension
- Palpitations / tachycardia
8
Q
Special Information
A
Concentration: 50mg/ 1ml
- For mild allergic reaction (rash, urticarial) Benadryl is the only medication.
- For acute allergic reaction and anaphylaxis Epi IM is given first.
- Cumulative depressant effects occur in the presence of alcohol and/or other sedatives.
- Benadryl is priority in mild allergic reactions, epinephrine is priority in moderate/acute rxns.
- Anticholinergic properties help to correct drug-induced cholinergic and dopaminergic imbalances that cause extrapyramidal reactions.
- Extrapyramidal reaction may be seen 7-10 days after ingestion of medications.
9
Q
Class
A
Antihistamine
10
Q
Extrapyramidal reactions:
A
- Facial muscle twitch
- Full body spasm
- Neck muscle contraction
- Head deviation
- Occulogyrations