boots- Histamine exam 2 Flashcards
what tissues can histamine be found in?
GI tract, CNS, dermis, lungs
these are referred to as ‘non-mast cell pool’
what is ‘mast cell pool’
histamine is found in mast cells in CT and basophils in circulation
T/F
‘**mast cell pool ‘ **consist of rapid turnover- continuous (constitutive) production and release?
FALSE:’
non mast cell pool’ consist of rapid turnover- continuous (constitutive) production and release?
mast cell pool: **stored in secretoy granules, after depletion stores are slowly replenishes
what drug can stimulate the release of histamine?
morphine
what **drugs ** _inhibit _ histamine release?
cromolyn sodium- ‘mast cell stabilizer;
catecholamines- epi
phosphodiesterase
glucocorticoids
what are the other stimulats for release of histamine?
- immune-induced (IgE)
- drug-released
- plant and animal stings
- physical injury or disease that disrupts mast cell
H1 receptor activation can lead to what?
- contraction of smooth muscle –> bronchoconstriction
- vasodilation then contraction of vessels –> hypotension, shock and edema
- positive inotropic effect
- CNS stim
H2 receptor activation can lead to the following:
- increased gastric secretion
- positive inotropic
- increase heart rate
list the 1st generation H1 blockers
- pyrilamine/tripelenamine
- diphenydramine-benedryl
- dimenhydrinate
- chlorpheniramine
- cyproheptadine
- promethazine
- trimeprazine-prednisolone
- meclizine
- cyclizine
- hydroxyzine
what 1st generation H1 blocker is used to treat old dog vestibular dz?
meclizine
what 1st generation H1 blocker is also used as an appetite stimulant in cats?
cyproheptadine
what 1st generation H1 blocker is also used an an anti-emetic, antitussive and sedative?
Diphenydramine (benedryl)
what are the 2nd generation H1 blockers?
- astemizole
- terfenadine
- loratadine (claritin)
- fexofenadine (allegra)
what generation last longer..
1st or 2nd?
2nd generation
they last 12-24 hours
T/F
2nd generation H1 blockers cause sedation
FALSE!!
1st generation H1 blockers cause sedation because cross BBB
T/F
1st generation H1 blockers last 12-24 hours
FALSE!!!
1st generation are short. **they last only 3-12 hours, but have a wider distribution and cross BBB
what are the H2 blockers?
- cimetidine
- famotidine
- ranitidine and nizatidine
which H2 blocker’s immunomodulating effects inhibit T cells and enchance CMI and can treat equine melanoma and reduce gastric acid motility?
Cimetidine
what H2 blocker is a _hepatic microsomal enzme inhibito_r?
cimetidine
which H2 blocker is used for gastric acid control only?
famotidine
which H2 blockers are used for gastric acid and also for their GI Prokinetic activity?
ranitidine and nizatidine
