Antihistamines Flashcards
What is a histamine
A ubiquitous biogenic amine
Where can histamines be found or synthesized
By almost all mammalian tissue
In humans where can histamines be found (cells,etc)?
Mast cells (tissue), basophils (blood cells), interstitial mucosa and CNS
The H1 receptor for histamine regulates
Sleep/walking, cognition, memory, seizure threshold
During an allergic reaction how is histamine released
Through the degranulation of mast cells
What are histamine effects
Vasodilation (decrease in BP), increased capillary permeability (hives), bronchoconstriction(wheezing), pain, itching in cutaneous nerve endings(hives, flares)
What are the different classifications of antihistamines
1st generation, 2nd gen and topical
Difference in 1st gen and second gen regarding H1 receptor selectivity
Gen 1 non selective, gen 2 selective
Which is more suitable for use (gen 1 vs gen 2) especially for infants, children and elderly and why
Gen 2 there are more studies, and dosing is based for science
Which generation cross the BBB and which one does not
Gen 1. Gen 2
Which one impairs alertness, cognition, learning, memory and performance
Gen 1
What do antihistamines end in?
-ine
Which gen does not accumulate in plasma with daily dose
Gen 2
What is the onset of action for gen 2 antihistamine and the duration
.7-2.4 hours with a duration of 24 hours
Which gen should be used for allergic rhinitis antihistamine? What is its strength of recommendation
2nd. Grade A
