HEENT Flashcards
What is histamine?
chemical messengers that mediate allergic and inflammatory reactions, gastric acid secretion, and neurotransmission
Where is histamine located?
In mast cell granules. A lot in nose, mouth, skin, internal body surfaces, blood vessels (non-mast cell in stomach and brain)
How is histamine released?
immune-mediated, degranulate quickly when exposed to appropriate antigen chemical or mechanical release
What are the histamine receptors?
H1 and H2
What does H1 do?
Stimulates sensory nerve endings, cause bronchoconstriction and increase nasal and bronchial mucus
Increase **capillary permeability (swollen stuffy nose)–> edema–>vasodilation**–> decreasing BP
What does H2 do?
Stimulates gastric acid secretion, increases capillary permeability and vasodilation, also increase heart rate and contractility
What are the oral antihistamines’ MOA?
Block H1 receptor-mediated response to histamine
Competitive binding
How do first gen oral antihistamines work?
Penetrate the CNS, cause sedation (cross blood brain barrier), interact with other receptors…anti-cholinergic properties (urinary retention/constipation)
How do second gen oral antihistamines work?
Minimal to none distrubution into CNS, specific for H1 receptors only. Do not cross blood brain barrier
What is the indication for medication regarding allergic rhinitis and uticaria?
Second gen preferred due to less sedation (loratadine (claritin), desloratadine (Clarinex), fexofenadine (Allegra)), possible mild sedation with cetrizine (zyrtec)
Reduces sneezing, itching, rhinorrea
What are the indications for oral antihistamines pregnancy induced N/V?
Doxylamine (Unisom) + B6
What are the options of oral antihistamines for motion sickness prevention?
Diphenhydramine (Benadryl, Unisom), hydroxyzine (Visatril, Atarax), meclizine (Antivert)
What are the indications of oral antihistamines for insomnia?
Diphenhydramine (Benadryl, Unisom) and doxylamine (Unisom) (common in OTC sleep aids and night time cold and cough meds….) only for short term use
What are the indications of oral antihistamines for antiparkinsonism effects?
diphenhydramine (benadryl) is most effective –> suppresses extrapyramidal symptoms of certain antipsychotics
What oral antihistamines are most associated with sedation as a side effect?
Common with first gen –> most with diphenhydramine (benadryl), hydroxyzine (vistaril, atarax)
Slight with chlorpheniramine (chlor-trimeton) and meclizine (Antivert)
Can see opposite effect in children
What oral antihistamines are most associated with anticholinergic effects as a side effect?
more common with first generation (worse with diphenhydramine)
What are some risks of DDI with oral antihistamines?
Potentiate CNS depressants (alcohol), anticholinergic effects, worsen urinary retention in BPH, decrease effectiveness of cholinesterase inhibitors used in alzhiemers, many are CYP2D6, 3A4 substrates/inhibitors
What are ex. of intranasal antihistamines?
Azelastine nasal (astelin), olopatdine nasal (patanase)
What are indications of intranasal antihistamines?
More effective than oral agents (try those first!), particularly more effective against nasal congestion less effective than intranasal corticosteroids
What are potential side effects of intranasal antihistamines?
bitter taste, nasal irritation, epistaxis, rare sedation/anticholinergic effects
What are examples of intranasal corticosteroids?
beclomethasone nasal (Beconase AQ), Budesonide nasal (Rhinocort Aqua), Fluticasone propionate nasal (flonase), Mometasone nasal (nasonex), Triacmcinolone nasal (nasacort AQ)
What is the mechanism of action for intranasal corticosteroids?
Reduces proinflammatory mediators -> PGs, LTRs, cytokines (prostaglandins, leukotrienes, cytokines)
Vasoconstriction of nasal passages –> decreases sneezing, itching, rhinorrea, nasal congestion
What are associated symptoms of intranasal corticosteroid use?
Local irritation, burning/stinging, epistaxis
What are examples of mast cell stabilizers?
Cromolyn inhaled (Intal)
What is the MOA of mast cell stabilizers?
Stabilizes mast cell and eosinophil plasma membrane –> prevents degranlation of mast cell, stopping release of histamines, leukotrienes, etc
What are the indications for mast cell stabilizers?
NOT FIRST LINE…
alternative daily therapy for mild asthma
Prevention of bronchoconstriction caused by unavoidable allergen, cold weather, exercise (before exercise/unavoidable allergen)
NOT rescue therapy…slow acting
What are the side effects of mast cell stabilizers?
Throat irritation, dry throat, dysgeusia (bad taste in mouth), cough
What is a leukotriene receptor antagonist?
Montelukast (singulair)
What is Montelukast (Singulair)?
Leukotriene receptor antagonist
- decreases inflammation in airway
- 2nd line for mild intermittent disease esp with comorbid mild, persistent asthma
- can be used in children as young as 6 months + older
- only for asthma & allergies
- does not work on nose, only airway
When should you consider antibiotics for bacterial sinusitis?
Greater than 10 days, facial/dental pain, fever, maxillary edema/puffiness…double hump sign
How do you treat acute bacterial sinusitis?
Augmentin
PCN allergy: clindamycin, cefdinir, doxycycline (no <8yo)
Macrolides no…high resistance
Sulfa no…high resistance
Fluoroquinolones no…avoid when possible (do not use in pediatrics)
**Levaquin, Moxifloxacin **
What are examples of oral nasal decongestants?
pseudophedrine (sudafed), pseudoephedrine/loratidine (claritin-d), phenylephrine (OTC usually a combo)
What are the MOA of oral nasal decongestants?
stimulates both alpha and beta adrenergic receptors, induce release of norepinephrine from nerve endings, similar actions to epinephrine VASOCONSTRICTION (less potent)
What’s the clinical use of oral nasal decongestants?
for allergic rhinitis, common cold, sinusitis, etc. Phenyelphrine NOT LESS EFFECTIVE nasal dec. than pseudophedrine (equal in efficacy)
What was the Combat Methamphetamine Epidemic Act of 2005?
pseudophedrine is a methamphetamine precursor –> used for illegal meth production, requires customer ID, behind the counter,
What are the adverse effects of oral nasal decongestants?
elevated BP, urinary retention
insomnia, headache, tachycardia, palpitations, anxiety, tremor, nausea
Who should you not prescribe oral nasal decongestants to?
hypertensive and BPH patients
Use Coricidin HBP in HTN
What are examples of topical decongestants?
phenylphrine (neo-synephrine)
oxymetazoline nasal (afrin)
What is the MOA of topical decongestants?
immediate response
alpha agonists – vasoconstriction in nasal mucosa and reduce airway resistance
rapid onset of action, few systemic effects with aerosol – increased systemic adverse effects if PO
What is the clinical use for topical nasal decongestants?
allergic rhinitis, common cold, etc…SHORT TERM..3-5d course
epistaxis
What are adverse effects of topical nasal decongestants?
rebound congestion, used more than recommended days
Elevated BP, urinary retention avoid in HTN and BPH
insomnia, headache, tachycardia, palpitations, anxiety, tremor, nausea
What category is dextromethorphan?
antitussive
What do antitussives do?
cough suppressant
How is dextromethorphan OTC?
formulated alone or in combo with guaifenesin (Mucinex-DM) OR phenylephrine, pseudophedrine, acetaminophen
What is dextromethorphan?
structurally related to codeine, depresses medullary cough center…relatively no analgesic action or addiction potential at recommended dose
What are other properties of dextromethorphan?
serotonin reuptake inhibitor (serotonin syndrome), NMDA receptor blocker (dissociative hallucinogen and euphoria at much higher doses than recommended)
What category is benzonatate?
antitussive
What is benzonatate?
Tessalon Perles anti tussive, local anesthetic (decreases sensitivity of airway stretch receptors and reduces drive to cough)
for cough >10yo, very minimal side effects
What category is codeine?
antitussive
What is the clinical use of codeine?
Moderate opioid agonist with antitussive effects, suppresses response of CNS cough center at doses that do not cause analgesia
What are side effects of codeine?
N/V, constipation, sedation, addictive potential
Prodrug: analgesia effect needs conversion to morphine by CYP2D6
What is an expectorant?
Med that thins airway mucus
What category is guaifenesin?
expectorant
How is guaifenesin OTC?
combo with dextromethorphan, phenylephrine, pseudoephedrine (Mucinex-D), acetaminophen
alone = mucinex
What are the side effects of guaifenesin?
no antitussive effects, may cause N/V at doses higher than recommended (elderly), rarely causes uric acid nephrolithiasis
so with kidney stone history do not prescribe!
What types of glaucoma are there?
Closed-angle: treated in hospital, medical emergency
Open-angle: chronic disease state, treated with eye drops
What are drugs to avoid in glaucoma?
antihistamines, anticholinergics, beta-agonists, corticosteroid eye drops
What are glaucoma treatments?
Prostaglandins
Non-selective beta blockers
Carbonic anhydrase inhibitors
Cholinergic agonists
What are prostaglandins and their MOA?
1st line treatment of glaucomas
MOA: increases aqueous outflow
What are the prostaglandins clinical pearls?
take at night, cannot be administered with contact lenses
What are the side effects of prostaglandins?
changes in iris pigmentation (skin around eyes may darken too)
eyelash growth
eye redness, tearing, eye pain, lid crusting
What are examples of prostaglandins?
travoprost (Travatan Z), bimatoprost (Lumigan), Latanoprost (Xaltan)
What is the non-selective beta blockers’ MOA?
reduce aqueous humor production
What are the beta blockers clinical pearls?
exacerbation of resp conditions no asthmatics prescribed this, one form is a gel, requires shaking
What are some side effects of non-selective beta blockers?
burning, stinging, itching of eyes/eyelids
changes in vision
photosensitivity
What is the carbonic anhydrase inhibitors MOA?
reduces aqueous humor production
What are examples of carbonic anhydrase inhibitors?
Brinzolamide (azopt), dorzolamide (trusopt)
What are cholinergic agonists?
glaucoma treatment, also called “miotics”
What is the MOA of cholinergic agonists?
lowers intraocular pressure by increasing aqueous outflow
What are some clinical pearls for cholinergic agonists?
Glaucoma should be used 4x daily
also used in acute angle closure to prevent post-op elevation of IOP and counteract mydriasis from sympathomimetics,
use with caution of history of retinal detachment or corneal abrasion
What are allergic conjunctivitis antihistamine/decongestant treatments?
Naphazoline/pheniramine
What are allergic conjunctivitis antihistamine treatments?
ketotifen (OTC, zaditor), levocetrizine, emedastine
What to use instead of artificial tears?
BLINK
What NSAID can be used for allergic conjunctivitis?
ketorolac
What are allergic conjunctivits mast cell stabilizer treatments?
Nedocromil, cromolyn
What are allergic conjunctivitis antihistamine/mast cell stabilizer treatments?
azelastine (optivar), epinastine, olopatadine (pataday, patanase)
What are allergic conjunctivitis steroid treatments?
dexamethasone, prednisolone (too dangerous if viral, leave steroids for eye specialist)
What is the order of treatments for allergic conjuncivitis?
antihistamines –> mast cells –> combo of both –> steroids
What is the order of treatments for allergic rhinitis?
oral antihistamines –> intranasal antihistamines –> intranasal corticosteroids –> mast cell stabilizer –> leukotriene receptor agonist
What’s the order of treatments for bacterial conjunctivitis?
Polytrim (trimethoprim/Polymyxin B)–> Fluoroquinolones–> aminoglycosides (gentamicin, tobramycin)–> Macrolides (azithromycin, erythromycin)
What else are macrolides used for?
Shortly after birth for prevention of opthalmic neonatorum due to gonococcal infection
If topical otitis externa treatment doesn’t work, what’s next?
augmentin
What do you use for removal of cerumen?
Carbamide peroxide (OTC), helps soften cerumen..but potential for 2nd infection, local irritation, redness
Can you put eye drops in the ear?
Yes
Can you put ear drops in the eye?
NO
What is BPH?
benign prostate hyperplasia…there are a lof of things we have learned about where you should not give people some meds in this list!!
What is the MOA of dextromethorphan?
depresses medullary cough center, SSRI, NMDA receptor blocker
What is the MOA of benzoatate?
decreases sensitivity of airway stretch receptors
What is the MOA of codeine?
suppresses response of CNS cough center
What are examples of beta blockers?
x: timolol*, betaxolol, levobunolol, carteolol
Why aren’t carbonic anhydrase inhibitors used very often in practice?
must be used 3x daily..hard to remember..not often seen in practice
What are side effects of carbonic anhydrase inhibitors?
bitter and unusual taste
What are examples of cholinergic agonists?
pilocarpine, carbachol
