Allergic Rhinitis Flashcards
What type of cells are the nasal mucosa lined with and what do they release?
Mast cells
release histamine
Describe the Antigen-antibody response in allergic rhinitis
allergen interacts w/ IgE bound to mast cells –> histamine released –> immune response
(vasodilation, increased vascular permeability,
& production of nasal secretions)
What role does the ANS play in allergic rhinitis?
controls rich vascular tissue
SNS: constricts arterioles, reduces mucosal thickness, widens the airway
PNS: dilates arterioles, increases mucosal thickness, incr. stuffiness and runny nose
____ stimulation produces itching.
Sneezing occurs by ____ stimulation pathways.
Sensory nerve
vagal
Mast cell mediator: effect of histamine?
stimulates irritant receptors, pruritis, vascular permeability, mucosal permeability, smooth muscle contraction
Mast cell mediator: effect of leukotrienes?
smooth muscle contraction, vascular permeability, mucus secretion, chemotaxis, neutrophil chemotaxis
Describe the pathophysiology of allergic rhinitis
Late phase reaction: 4-8 hrs after initial exposure caused by cytokines primarily released by mast cells
- Persistent chronic sxs
- inflamed mucosa become hyper-responsive
What are the evidence-based Level A Tx recommendations for Allergic Rhinitis?
nasal steroids
oral antihistamines
intranasal antihistamines
immunotherapy
What medication class is an excellent choice for perennial rhinitis?
intranasal corticosteroids
MOA of histamine (H1)-Receptor antagonists
- competitive antagonist of histamine
- binds to H1 w/o activation and prevents histamine from binding
- anticholinergic (PNS) properties cause reversal of sxs
**Prophylactic works best
What is the best 1st/2nd generation H1-Receptor antagonist to give a pregnant patient and why?
1st gen – Chlorpheniramine (level B) because it has less sedation and anticholinergic affects
2nd gen – Cetirizine (Zyrtec)
histamine (H1)-Receptor antagonists contraindications and drug interactions?
contraindicated w/ Hypersensivity to formulation
Interactions - anticholinergics and CNS depressants (Benzos)
histamine (H1)-Receptor antagonists adverse reactions?
- anticholinergic effects - xerostomia, constipation, urinary retention
- CNS depression
- Paradoxical excitement
What are some medications under the histamine (H1)-Receptor antagonists drug class?
Intranasal and ophthalmic = Azelastine and Olopatadine
Topical = Diphenhydramine
MOA for decongestants
stimulates alpha-adrenergic receptors –> vasoconstriction
pseudoephedrine stimulates beta-adrenergic receptors –> increase HR, contractility, and bronchial relaxation
Although topical decongestants are more effective for treating allergic rhinitis, overuse can cause…
Rebound congestion
What are some examples of decongestants?
intranasal (sprays) & ophthalmic (drops):
- Phenylephrine, Tetrahydrozoline, Naphazoline, Oxymetazoline
Oral: Pseudoephedrine, phenylephrine
Contraindications and drug interactions for decongestants?
Contraindicated w/ hypersensitivity, and MAOI use w/in 14 days
Interactions: SNRI’s (tachycardia) and
sympathomimetics (enhance ADE’s)
ADE’s and monitoring in Decongestants?
Rebound congestion w/nasal formula after 3-5 days of use, tachycardia, & HTN
HR and BP
MOA for inhaled corticosteroids
Reduce mediator release, formation, activity –> reduce inflammation
reverses dilation –> mild vasoconstriction
inhibit mast cell mediated late phase reaction
Inhaled Corticosteroid use will show slight improvement of sxs in ____ & peak responses in ____.
few days
2-3 weeks
What can inhaled corticosteroids also be useful in treating aside from allergic rhinitis?
nasal polyps
Give examples of inhaled corticosteroids (nasal & inhaled). What are the adverse drug reactions?
Beclomethasone, budesonide, flunisolide, fluticasone, mometasone
HA, pharyngitis, cough, epistaxis (nasal formulation)
MOA for Leukotriene receptor antagonist
inhibition of cysteinyl leukotriene receptor (mast cells release leukotrienes)
LOX inhibitor - Zileuton
What drug class do Leukotriene Receptor antagonists need to be combined w/ in order to be effective?
Antihistamines
Leukotriene receptor antagonists contraindications and drug interactions?
contraindicated w/ hypersensitivity
Interactions w/ CYP3A4 and CYP2C9
Leukotriene receptor antagonists adverse reactions and what should you monitor?
Adverse rxns: HA, mental status changes, dyspepsia, dizziness, fatigue
Monitor mental status and allergy control
Cromyln nasal spray MOA, side effects, and how long until symptomatic relief?
MOA: mast cell stabilizer
can cause local irritation
2-4 weeks for sxs relief
Ipatropium nasal spray MOA, drug interactions, and how long is it safe to use?
MOA: anticholinergic and inhibits secretions
may enhance anticholinergic effects of other agents
safety and efficacy beyond 4 days not est.
H-2 Receptor antagonist MOA, examples, and what drug can it be combined w/ in allergic reaction, urticaria?
MOA: competitively inhibits H2 receptor, prominent in parietal cells, prevents gastric acid secretion
Cimetidine > Ranitidine, Famotidine, Nizatidine
(Raniti/famotidine - fewer side effects)
Combine w/ H-1 blocker
What approach should you take in treating a patient w/ allergic rhinitis?
if environmental controls don’t work try single-drug tx based on sxs:
Antihistamines - sneezing, itching, rhinorrhea, ocular sxs
Decongestants (systemic) - nasal congestion
Intranasal steroids - sneezing, itching, rhinorrhea, and nasal congestion
Describe the pathophysiology of a cough.
- Voluntary vs. involuntary
- acute vs. subacute vs. chronic
involuntary - “cough center,” medulla oblongata
voluntary - cerebral cortex
acute (<3 wks) – commonly viral URI
Subacute (3-8wks) – bacterial or asthma
chronic (>8 weeks) – postnasal drip syndrome, GERD, asthma
Hydrocodone/Codeine MOA and examples
MOA: cough suppression, direct central action in the medulla
Codeine/Guiafenesin (Robitussin AC)
Codeine/Promethazine (Phenergan w/Codeine)
Hydrocodone/Chlorpheniramine (Tussionex)
Hydrocodone/Codeine contraindications and adverse reactions
contraindicated w/hypersensitivity
interactions: CNS depressants, drug abuse/dependency, nausea
Hydrocodone/Codeine drug interactions and what should you monitor?
CNS depressants
monitor frequency of use
MOA of Benzonatate
- suppresses cough by topical anesthetic action on respirator stretch receptors
- relative to tetracaine
Benzonatate adverse reactions and contraindications?
ADE’s mental confusion, visual hallucinations, sedation
contraindicated in children under 10yrs d/t increased risk of death
MOA of Dextromethorphan (DXM)
Decreases sensitivity of cough receptors
Suppresses medullary cough center
What are examples of Dextromethorphan (DMX) and what is it structurally related to?
DXM Poylstirex (Delsym) DXM Hydrobromide
codeine
Contraindications, ADE’s and drug interactions of Dextromethorphan (DXM)?
Contraindicated w/ MAOI administration w/in 2 weeks
ADE’s: confusion, potential serotonin syndrome
Interacts w/ SSRIs - enhances the serotonergic effect
MOA of Guaifenesin
irritating gastric mucosa and stimulating respiratory tract secretions –> increase respiratory fluid volume and decrease mucous viscosity
Guaifenesin: What are the adverse reactions, contraindications, and what should you monitor
ADE’s: dizziness, drowsiness, HA, N/V
Contraindicated w/ hypersensitivity
Monitor hydration status
