antihistamine pharm

Question 1

what happens when H1 receptors are activated?

Answer 1

bronchoconstriction
stimulation of NO formation (vasodilation)
endothelial cell contraction
increased vascular permeability

Question 2

what happens when H2 receptors are activated?

Answer 2

gastric acid secretion by parietal cells in the stomach

Question 3

what are the main applications of H1 antagonists?

Answer 3

allergy and hay fever
symptoms of insect bites and stings
symptoms of contact flora poisoning
attenuation of motion sickness and vertigo

Question 4

what is unique about the 1st generation antihistamines?

Answer 4

short duration of action
highly sedative
anticholinergic side-effects

Question 5

name the 1st generation anithistamines (4)

Answer 5

diphenhydramine
dimenhydrinate
chlorpheniramine
hydroxyzine

Question 6

name the 2nd generation antihistamines (4)

Answer 6

foxofenadine
desloratadine
cetirizine
azelastine

Question 7

what are the adverse effects of 1st generation antihistamines?

Answer 7

sedation
antimuscarinic effects (xerostomia, urinary retention)

Question 8

what is adverse effect of 2nd generation H1-antagonists?

Answer 8

mild cognitive disturbance

Question 9

whats unique about desloratadine?

Answer 9

much greater binding affinity to H1 receptors than loratadine

• lower affinity for muscarinic receptors
• long half life (27 hours)

Question 10

how does azelastine work?

Answer 10

2nd gen. H1 antagonist

• inhibits both histamine and LT activity
• blocks Ca2+ mobilization and 5-Lipoxygenase path
• inhibits PAF through receptor antagonism