PreOp Meds: H1 Antagonist concepts Flashcards
1
Q
Histamine-1 receptor activation can mimic these other receptor types.
A
- Muscarinic
- Cholinergic
- 5HT3
- α-adrenergic
2
Q
Histamine binding to H1 receptors generally elicits what effects?
A
- Hyperalgesia
- Inflammatory pain (insect stings)
- Allergic rhino-conjunctivitis s/s
3
Q
How prone are H1 antagonists to tachyphylaxis?
A
- Very little tachyphylaxis development
4
Q
What signs/symptoms occur with excessive H-1 & H-2 activation?
A
- Hypotension (from NO) release
- ↑capillary permeability
- Flushing
- Prostacyclin release
- Tachycardia
5
Q
What are the side effects of H1 antagonists?
A
- Drowsiness/sedation
- Blurred vision
- Urinary retention
- Dry mouth
6
Q
What are four examples of H1 receptor antagonists?
A
- Diphenhydramine (Benadryl)
- Promethazine (Phenergan)
- Cetirizine (Zyrtec)
- Loratidine (Claritin)