Benadryl feb 242022 Flashcards
What is Diphenhydramine also known as?
Benadryl
What are the primary indications for Diphenhydramine?
- Anaphylaxis
- Allergic Reaction
- Extrapyramidal symptoms secondary to Haldol or Metoclopramide
What classification does Diphenhydramine fall under?
Antihistamine
What type of receptors does Diphenhydramine block?
H1 and H2 receptors
What effects does Diphenhydramine have by blocking histamine receptors?
- Decreased bronchoconstriction
- Decreased capillary dilation
What are the onset times for Diphenhydramine when administered IV/IO and PO?
IV/IO immediate; PO within 1 hour
What is the peak effect time for Diphenhydramine?
1-3 hours
What is the half-life of Diphenhydramine in children?
4-7 hours
What is the half-life of Diphenhydramine in adults?
7-12 hours
What is the half-life of Diphenhydramine in the elderly?
9-18 hours
What are the symptoms of an allergic reaction?
- Runny nose
- Itchy/red/watery eyes
- Hives
- Itchy rash
What characterizes anaphylaxis compared to an allergic reaction?
Response from at least two body systems
What are the symptoms of anaphylaxis?
- Shortness of breath (SOB)
- Urticaria
- Nausea/Vomiting/Diarrhea (N/V/D)
- Swelling
- Dysphagia
- Diaphoresis
What are the extrapyramidal symptoms associated with Haldol or Metoclopramide?
- Akathisia
- Dystonia
- Parkinsonism
- Tardive dyskinesia
What are the contraindications for administering Diphenhydramine?
Hypersensitivity to Diphenhydramine or Dimenhydrinate
What are common adverse effects of Diphenhydramine?
- CNS Depression
- Sedation
- Impaired attention, perception, psychomotor skills
- Hepatic impairment
- Muscarinic blockade
What is the adult dose of Diphenhydramine?
1 mg/kg IM/SIVP to a maximum of 50 mg or 50 mg PO
What is the maximum dose of Diphenhydramine for patients older than 65?
1 mg/kg to a maximum of 25 mg
Is there a repeat dose for Diphenhydramine?
No
What is the pediatric dose of Diphenhydramine?
1 mg/kg PO/IM/SIVP to a maximum of 50 mg
What is important to differentiate when assessing a patient for Diphenhydramine treatment?
Anaphylaxis vs allergic reaction
What is the primary treatment for anaphylaxis?
Epinephrine
Where should IM medications be administered?
In the vastus lateralis
What should you do if you are in doubt about administering Diphenhydramine?
Contact OLMC
