Treatement of Allergic Rhinitis Flashcards
What is triggered by inhalation of allergen in a person with sensitized immune system?
production of IgE.
What Does IgE bind to?
IgE binds to mast cells and basophils containing histamine.
What is the pharmacotherapy of allergic rhinitis based on?
Type of rhinitis present
Most prominent symptoms
Patient age
What is the most effective single therapy for A.R.
Glucocorticoid nasal spray (intranasal glucocorticoid)
What are the general MOA’s for medications for A.R.
Allergen avoidance Leuoktriene modifiers- Antihistamines Steroids Allergen immunotherapy.
MOA for INGC’s (intranasal glucocorticoids)
Inhibit inflammation of nose by inhibiting cytokines/chemokines.
Binds to intracellular GC receptors of inflammatory cells. Change of the receptor activates genes to transcribe mRNA for anti-inflammatory proteins. Suppresses transcription of cytokine/chemokine genes surpasses inflammation
ADME of INGC’s
A: minimally systemic 1st gen- 10-50% bioavailability 2nd gen-<2% bioavailable D: N/A M: Hepatic - 1st pass met. E: N/a
Example of first generation INGC’s
Rhinocort, Nasacort,
Example of second generation INGC
Flonase, nasonex Veramyst
How soon should the pt expect an INGC to start working?
may take 3-5 days or even weeks before full relief is realized (onset-few hours).
Can an INGC be used PRN?
yes but not as efficacious as continued use.
When should an INGC be used vs. oral antihistamine?
Relieving congestion, relieving ocular symptoms, Raises threshhold for developing symptoms after exposure (when used continuously)
ADE of INGC
Nasal irritation, drying, burning, bleeding, Discomfort from throat runoff, Nasal septum perf.
Growth suppression in children.
DI of INGC
Fluticasone and strong CYP3A4 inhibitors. Adrenal suppression.
Forms of INGC’s that are new to market and Method of use for these
Dry powder formations (HFA).
MOU: Tilt head back, dispense spray, hold breath, exhale through mouth. (different than spray INGC’s which you tild head down)
Where are H1 histamine receptors located?
Throughout body, smooth muscles, vascular endothelial cells.
What is the function of H1 histamine receptors?
Systemic vasodilation and increased cell permeability
What Class of histamine receptors does the term antihistamine refer to?
H1
MOA oral antihistamines
Block action of Histamine at H1 receptors (inverse agonists-not antagonists)
What are the 2 categories of antihistamines?
1st gen-crosses BBB-causes sedation CNS side effects
2nd gem-does not cross BBB.
P’Kinetics of Oral antihx.
A: Rapid (10-30 min)
D: 60-70% protein bound
M: Minimal with exception of desloratadine (extensive 1st pass met)
E: Primarily urine
What is the duration of action for anthix.
1st gen: 1-6hours
2nd gen: 6-24 hours
Examples of 1st gen oral antihx.
OTC: Diphenhydramine (Benadryl), Chlorpheniramine, Clemastine, Brompheniramine.
Safety warnings with 1st gen oral antihix.
Lipophilic-easily cross BBB (CNS symp.)
Intellectual and motor function impairment
Not recommended for elderly.
