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.
What are the ABC of treating anaphylaxis
- Airway
- Breathing
- Circulation
Tx of Anaphylaxis
- Simple BLS and ABC’s
- Epinepherine
- Anti-histamines (both H1 and H2 receptors)
- Corticosteroids (for late phase rxn)
- Treat Hypotension: IV fluids, Epi Drip
- Tx Bronchodilators; albuterol
Observe min. 24hrs, benadryl for 24hrs
Rebound anaphylaxis (late phase)- repeat epinepherine drip, repeat antihistamine + H2 blocker
*always have them f/u w/ primary care provider
What are the 2 phases of anaphylaxis?
- Acute phase
- Late/Delayed Phase
Shock symptoms
anxiety, agitation
bluish lips fingernails
chest pain
confusion dizziness
light headed
pale. cool clammy skin
profusely sweating
Risk Management for anaphylaxis
EDUCATE!!!
- teach avoidance
- bracelet and an emergency action plan
- stress importance of always have current EpiPen on hand, practice, emphasize need for follow up care!
Screening patients at risk of anaphylaxis
Ask if ever had severe allergic rxn that caused
- trouble breathing
- severe hives/swelling
- severe vomiting
- severe diarrhea
- dizziness
