Pharm of Allergy and Anaphylaxis Flashcards
Broad Allergy Tx Options
- avoidance of triggers; no carpet or upholstered furniture, no pets, maintain heating/cooling systems, no smoking
- medications
- allergy injections
Allergy Medication Arsenal
- antihistamines (1st and 2nd generation)
- decongestants
- cromolyn sodium (mast cell stabalizer
- intranasal glucocortioids
- single most effective agent, need to start in advance b/c takes longer to effect
- Ipratropium (intranasal cholinergic)
- Montelukast (leukotriene inhibitor)
Ideal drug for allergic rhinitis should have the following features…
- inhibit both early and late phases
- H1 blocker
- fast acting, to control early phase
- dosing 1x/daily for compliance
- no side effects
- manage all symptoms
- intranasal administration
1st generation Antihistamines
- drugs
- MOA
- onset
- effect
- side effects
- CI
- Diphenyhydramine (Benadryl)
Hydroxyzine (Atarax), cholrpheniramine (Chlor-trimetion) - blocking the actions of h1 (histamine) at receptor sites, does not block histamine release.
- 15-30mins
=reduced itching sneezing and rhinorrhea not congestion
- SE- sedation, anticholinergic effects. (no shit, no spit, no pee, no see)
- CI- lactating mothers, glaucoma, BPH, elderly, children
What is the difference between H1 and H2 blocker?
-H1 blocker is in nose and resp. tract induces smooth muscle contraction, ex. benadryl
H2- blocking in GI, ex. Zantac
2nd Generation Antihistamines
- drugs
- MOA
- onset
- Effect
- SE
- Loratadine (Claratin)
- Fexofenadine (Allegra)
- Cetirizine (Zyrtec)
- MOA: inhibit histamine H1 reeptors
- onset: rapid onset, maximum effect 1-2.5hrs
- effect- reduced sneezing, itching, rhinorrhea, NOT congestion
SE- anticholinergic effects (no shit no spit no see no pee) less SE than 1st generation, less sedating IS long acting
Decongestants in the tx of Allergy
- drugs
- MOA
- Effect
- SE
- CI
- pseudoephedrine (Sudafed) (Oral)
Pseudoephedrine (Afrin) (intranasal)
mech. - alpha adrenergic agonist.
effect: vasoconstriction, restrict blood flow to nasal mucousa that has been dilated by histamine
SE- HA, nervous, irritablitly, tachycardia, palpitations insomnia, HAS NO influence on pruritis, sneezing, or nasal secretion
CI- hypertension, cardovascular disease, hyperthyroidism. glaucoma, co- use w/ MAOIs (monoamines oxidase inhibitors)
What is Rhinitis Medicamentosa? (RM)
-prolonged use of topical decongestant, may induce rebound congestion upon withdrawl. leads to inflamm hypertrophy of nasal mucosa.
ex, afrin over use (>3days)
Combo drugs: oral non-sedating antihistamine-decongestant
- Fexofenadine/Pseudoephedrine (Allegra)
- Loratadine/Pseudoephedrine (Clartin D)
- Cetirizine/pseudoephedirne (Zyrtec D)
Cromolyn Sodium (Nasalcrom)
- what drug class?
- moa
- effects
- SE
- time to efficacy
- leukotriene receptor antagonist
- mast cell stabalizing agent»> reduces release of histamine and other mediators
- reduces nasal pruritis, sneezing, rhinorrhea, congestion
- no serious effects
- Helpful in prophylaxis only, must start 2-4weeks prior, frequent dosing (Q4hr)
Intranasal Glucocorticoids (INGCs)
- types
- mechanism
- effect
- SE
- time to efficacy
- fluticasone proprionate (Flonase)
-mometasone (nasonex)
-Beclomethasone dipropriate aqueous (Beconase)
-Budesonide (Rhinocort)
-Flunisolide (Nasarel)
-Triamcinolone acetonide
(Nasacort) - disabling cells that present ag to aby, reduce mast cell degranulation, reduce inflamm by limiting late phase response, suppress neutrophil chemotaxis, mildly vasoconstrictive, reduce intracellular edema.
effects: reduce nasal blockage, pruritis, sneezing, rhinorrhea
SE- nasal irritation, bleeding
-efficacy; therapeutic 1-3days but MAX efficacy up to 3weeks, compliance is critical
What is Ipatropium Bromide (Atrovent) good for? why?
- what class of drug is this?
goood for runny nose, reduces substance p
Anti-cholinergic nasal spray
What is IMontelukast (singular) good for? why?
helpful for runny nose and congestion, not first line therapy
*mainly used for asthma but also approve for AR
Treatment for eye allergies
- Normal saline
- Azelastine (Optivar)– inhibits histamine release from mast cells
- Olopatadine (patanol)– inhibits histamine release from mast cells
- Naphazoline/pheniramine (Opcon-A)– Naphazoline decreases congestion, pheniramine is an antihistamine, has rebound effects
Allergy injections
-when to do
- used when medication and avoidance dont work
- leave this to the “pros” allergist.
Stepwise approach to Medicines for Allergic Rhinitis
Step 1: avoidance of allergic factors,
Step 2: if continued mild intermittent sx use non-sedating antihistamine and/or decongestants prn
Step 3: persistent to mild/moderate sx use intranasal steroid therapy 1-2 weeks prior to season, nonstedating antihistamine and/or decongestant prn, topical ocular antihistamine w/ or w/o vasoconstrictor or topical eye mast cells stabalizer
Step 4: Severe sx; use topical nasal corticosteroid, non-sedating antihistamine and or decongestant, short term burst of oral corticosteroids (Prednisone Burst pack- start high dose and then taper them off. If using this more than 1x/yr they need immunotherpy) if inadequate response consider immunotherapy
Allergic Rhinitis Physical Exam Findings
Eyes- red, allergic shiners, stringy mucus,
Nose- red, sowllen, polyps, clear drainage, cyanotic/boggy nasal mucosa
Throat- post nasal drip
Chronic Sinusitis Physical Exam Findings
-what is the key to this dx.
Frontal HA, pain, pressure
Nose- thick yellow nasal discharge
Cough- thick yellow-green sputum x1week
Bad breath
- may experience tooth pain- maxillary sinus runs along trigeminal nerve that innervates the mouth causing pain.
- key to sinus infection dx is TIMELINE, most clear up on own w/ anti-histamine, once 10days pass w/ no relief its definitely sinusitis.
Most common bacterial cause of acute sinusitis? Which abx do we treat this with?
strep. pneumo
H. flu
Moraxella Catarrhalis
-amoxicillin
Perennial allergic rhinitis Tx
antihistamine/decongestant + nasal steroid (+ nasal saline)
Tx of Allergies (steps)
- avoidance
- reduce exposure
- symptom relief (antihistamine/decongestants, Steroids)
- Desensitization (refer to specialist)
Anaphylaxis
- what is it?
- What is it a result of?
- what type of hypersensitivity is it?
- acute systemic ( multi-system ) allergic rxn (life-threatening rxn)
- results from re-exposure to Ag that elicits an IgE mediated response, often caused medications, foods, insect stings
- Type 1 hypersensitivity
Steps and Effects of Anaphylaxis on different body systems
*Bee sting, Ag enters tissue and binds to IgE on Mast cell.
Mast cell releases chemical mediators (histamine, leukotrienes, prostaglandins, cytokines) that work on these systems…
- lungs= bronchospasm *(this is what ppl die of acutely), vasoconstriction, edema
- Heart= decreased output, increased HR, decreased coronary flow, decreased BP d/t vasodilation
- peripheral blood vessels= vasodilation, leaky
- tissue= puritus, urticaria, edema
- GI= smooth muscle contraction and diarrhea
When to use epi-pen
-at any sign of anaphylaxis, do not hesitate to use, there are no CI.
