Histamine & Serotonin Flashcards
MA: histamine
binds receptor–H1 & H2
PE: histamine
constricts larger vessels like veins, dilates smaller BV. Edema, itching, increased alertness, constricts bronchioles
MA: anti-histamines
block histamine receptor
PE: Antihistamines-H1 blockers
What would these treat?
sedative, anti-nausea, drying of mucous membrane, sunburn spray, dilates bronchioles.
These would treat–allergic responses, anti-emetic, anti-nauseant (motion sickness), sedatives
PE: Antihistamines–H2 blockers
blockade of H2 receptors decreases acid secretion in GI.
Anti-histamines: First generation H1 VS 2nd generation blockers do what
First Generation:
act on peripheral & central histamine receptors.
Enter the CNS.
“ZINE” & “AMINE”
Second generation: do not operate heavy machinery, fewer CNS effects, do not enter CNS, general allergies
Name the first generation H1 blockers
diphenhydramine, cleamastine, chloropheniramine, hydroxyzine, promethazine, tripeleamine
Name the second generation H1 blockers
loratadine, fexofenadine, desloratadine, cetirizine
Name the H2 blockers
cimetidine, ranitidine, famotidine, nizatidine
Cimetidine SE
gynecomastic & glactorhea, decreased sperm count
serotonin is synthesized from
tryptophan in the chromatin cells of the gut
PE: serotonin
smooth muscle constriction, itching, SSRI, causes nausea
What is carcinoid syndrome?
tumor of enterochromaffin cells, increase in serotonin, tryptophan all goes to serotonin production=tryptophan deficiency & niacin deficiency–>pellagra.
no CNS effects
Bronchospasm, diarrhea, skin flushing, fibrosis of the heart valves
What are the migraine agents that alter the serotonin system?
serotonin receptor agonists–>vasoconstriction
Triptans & ergot alkaloids
Sumatriptan
don’t use with MAO inhibitors or you will cause serotonin syndrome–>hyperthermia & muscle twitching.
Serotonin receptor agonist
