Antihistamines

Question 1

2nd generation antihistamines that block interaction of mast cell released histamine with H1 receptor

Answer 1

fexofenadine -terfenadine metabolite
loratadine
cetirizine -> hydroxyzine metabolite

Question 2

antihistamines used for motion sickness/nausea

Answer 2

cyclizine
meclizine
promethazine (phenergan)
dimenhydrinate (OTC)

Question 3

Where is the H1 receptor found?

Answer 3

smooth muscle, endothelium, brain

Question 4

Where is the H2 receptor found?

Answer 4

gastric mucosa, cardiac muscle, mast cells, brain

Question 5

What does cyproheptadine do?

Answer 5

first generation H1 blocker that also strongly blocks serotonin receptors (serotonin directly constricts vascular smooth muscle)

Question 6

Name H2 receptor blockers

Answer 6

cimetidine

ranitidine

Question 7

diphenhydramine
chlorpheniramine
bromopheniramine

Answer 7

OTC first generation antihistamines

Question 8

What does histamine do?

Answer 8

vasodilation (headache & flushing)

H1 activation causes NO release from endothelium -> vasodilation

Question 9

What asthma drug class can reduce histamine release?

Answer 9

beta2 agonist

Question 10

Receptors which 1st generation antihistamines interact

Answer 10

muscarinic, alpha, serotonin and local anesthetic receptor sites

Question 11

Where is the H4 receptor located

Answer 11

eosinophils, neutrophils, CD4 T cells