Antihistamines Flashcards
Which is both in Hpersensitivity 1 and 4?
Latex
Type 1 hypersensitvity pathway
B cell to an antigen as foreign
cloning occurs of b cells- plasma cells
Mast cells: in tissues/ basophils in blood
B cells give antibodies to mast/baso
can now respond to antigen
Anitgen binds to recptor: calcium and degranultion
How soon does type 1 hypersensitivity occur?
5- 30 min after reexposure
What enzyme is responsible for producing prostaglandins, leukotrienes, ad platelet activationg factor in hypersens. 1?
phosopholipase A2
How long does it take for type 4 hypersens?
2-3 days
Is there a histamine response in hyperssent.4?
no; t cell based not antibody based like 1-3
not responsive to antihistamines
Cold Compresses do what?
Cause vessels to shrink. act as decongestion
Hot: vasodilation
What is patient doing when rubbing eyes?
busting open mast cells
Actions of decongestions?
reduce redness
reduce leakage
Why is phenylephrine not commonly used as an allergy therapy?
it can produce rebound congestion and conjunctival medicamentosa
Which decongestion causes increase in IOP?
Naphazoline
Which decongestion causes decrease in IOP?
tetrahy
Wht is a stand alone topical antihistamine?
Emadine (Emedastine)
-Pregnancy B
2nd Generation
Wht is the fastest acting topical mast cell stabilizer?
Alocril/Nedocromil
Emadstine Effects
Serious: keratisis
Common: dry eye, headache, dry eye , bitter taste, abnormal dreams, , foreign body sensation, lacrimation
