Flashcards in Antihistamine Deck (20)
Histamine is released from what cells?
Basophil and mast cells
How is NO produced?
Arginine ---(NO synthase)--->citrulline + NO
H1 receptor is __ coupled receptor, and activation of it would cause?
Vasodilation via NO
Increase capillary permeability
Smooth muscle contraction
Pain and itch
Where are H2 receptor cells located and activation causes what?
H2 receptors are found in gastric parietal cells
Activation-->increase acid secretion
H1 antagonists are competitive or noncompetitive blockers? and what are the 1st and 2nd gen drugs?
What are the benefits of 2nd gen H1 blockers comparing with 1st gen?
2nd gen do not cross BBB--->non sedating
2nd gen do not block M--->unlike 1st gen
1st gen--->sedating/anti M
What are the 2 commonly used antiemetic H1 blockers? and what about nausea and vomiting in pregnancy?
Meclizine and promethazine
H1 or H2?
Allergic--->both H1 and H2
All the rest are for H1
What is the end product of 5HT metabolism?
Which 5HT receptor that is directly coupled to an ion channel? and what are the rest of the 5HT receptor coupled with?
The rest are G-protein coupled receptors
What is the mechanism of buspirone?
5HT1a partial agonist for chronic anxiety
What is the mechanism of "triptans" and what are they used for?
5HT1d agonist--->vasocontrict--->acute migraine
Are 5HT2 receptor inhibitory or excitatory in the CNS
What group of drugs that block 5HT2a receptor?
Atypical antipsychotic like olanzapine
What is the mechanism of cyproheptadine?
5HT2 blocker for serotonin syndrome
H1 blocker--->seasonal allergy
What does 5HT3 receptor do? and what drugs act on them?
"setrons" drugs block them--->antiemetic
What is the mechanism of ergotamine and what is it used for? side effect?
Alpha 1/5HT2 agonist--->vasoconstriction--->acute migraine
Prolonged vasoconstriction--->ischemia and gangrene/abortion
What other drugs can be used for acute migraine? and what drugs do we use for prophylaxis of migraine?
NSAIDs and acetaminophen
Propranolol (DOC)/verapamil/TCA/valproic acid
What is ergonovine used for?
Uterine smooth muscle contraction--->give IM after placental delivery