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West Los Angeles College
Therapeutic Agents for the Eyes, Ears, Nose, and Throat
Chapter 24
1
West Los Angeles College
The Eyes (Ophthalmic System)
⬤ Eyes link outside world to the mind ⬤ Images translate into impulses that create
lasting memories in the mind ⬤ Three different levels of eye specialists:
➢ Opticians make lenses ➢ Optometrists perform eye exams ➢ Ophthalmologists are medical doctors
2
• Muchofthesurgerycurrentlybeingperformedoneyesisbeingdoneusinglasers.
• Opticiansareskilledinmakinglensesthatcompensateforvisionloss,buttheycannotprescribemedications.Optometristsaretrainedtoperformeyeexaminationsandmayprescribecertainmedicationsfortheeye.Ophthalmologistsarephysicianswhotreatmajorconditionsaffectingtheeye,includingperformingeyesurgeries.
• Manyophthalmicagents,particularlyantibioticsandcorticosteroids,arealsocommonlyprescribedforuseintheear,whichisacceptablebecausetheophthalmicpreparationsaresterileandcanbeusedintheear.However,oticpreparationscannotbeusedintheeyebecausetheyarenotsterile;inaddition,thepHandotherqualitiesofoticformulationsmaypotentiallyinjuretheeye.
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Anatomy and Physiology of the Eye
⬤ Eyebrows shade eyes from light ⬤ Eyelashes (more than 200) catch debris, keep
eyes moist, and shade the eyes ⬤ Orbit is bony socket that holds the eye ⬤ Eye position is 100 degrees of peripheral
vision
3
• Theeyebrowscanalsokeepperspirationfromreachingtheeyes.• Theeyelidshavefourindividuallayers:theouterskin,themuscles,the
connectivetissue,andtheconjunctiva.• Bactericidalagentskillthebacteria,whereasbacteriostaticagentslimit
bacterialgrowth.Drugsthatarebacteriostaticareusedtoassistthebody’simmunesysteminfightingoffthebacteria.
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Anatomy and Physiology of the Eye (Cont.)
⬤ Conjunctiva is thin, transparent mucous membrane that covers anterior eyelids and sclera
⬤ Lacrimal gland, in orbit, secretes tear into eye; has ducts to nasal cavity
⬤ Lysozyme is enzyme in tears with antimicrobial properties
4
• Thescleraisthewhiteportionoftheeye.
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Eye Anatomy
5
From Potter PA, Perry AG: Fundamentals of nursing, ed 8, St Louis, 2013, Mosby.
• Figure24-1showstheanatomyoftheeye.
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Anatomy and Physiology of the Eye (Cont.)
⬤ Cornea: Transparent cover allows light into the eye ➢ Connective tissue ➢ Covered with thin epithelial layer ➢ No blood vessels: Nourished by aqueous humor
(tissue fluid) and oxygen ➢ Nerve fibers sensitive to pain
6
• Thecorneabulgestohelpprovidevisualacuity.
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Anatomy and Physiology of the Eye (Cont.)
⬤ Choroid coat: Layer inside sclera ⬤ Fovea: Innermost layer where sharpest vision
occurs ⬤ Sclera joins with iris and ciliary body in front of
eye ⬤ Iris: Colored part of eye to filter light
7
• Thechoroidcoatcontainsnumerousbloodvesselsthatsupplynutrientstotheothertissuesoftheretina,anditalsocontainspigmentedcellsthatabsorblightandpreventitfrombeingreflectedwithintheeyeball.
• Theirisisthecoloredpartofeyeseenthroughthecornea,whichconsistsofsmoothmusclesthatregulatepupilsize.
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Anatomy and Physiology of the Eye (Cont.)
⬤ Posterior cavity: Largest space in eye; surrounded by lens, ciliary body, and retina
⬤ Ciliary body: Forms ring around front of eye; holds lens in place
⬤ Vitreous body: Holds shape and form of eye ⬤ Vitreous humor: Nourishes and cleanses eye
8
• Whencertainfibersintheeyecontract,thechoroidcoatispulledforward.• Thiscausestheciliarybodytoshorten;thisthickensthelens,allowingtheeye
tofocusoncloseobjects.
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The Retina
⬤ Retina: ➢ Thin layer; contains layers of neurons, nerves,
pigmented epithelium, and membranous tissues ➢ Receptor cells responsible for vision
⬤ Six muscles responsible for eye movements
9
• Othermusclesopenandclosetheeyeanddilateandconstrictthepupil.
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Eye Muscles and Direction of Movement
10
• Whatactionsdothefourrectusmusclesperform?(Thesuperiorrectusrotatestheeyeupwardandinward.Theinferiorrectusrotatestheeyedownwardandinward.Themedialrectusrotatestheeyeinward.Thelateralrectusrotatestheeyeoutward.)
• Whatactionsdothetwoobliquemusclesperform?(Thesuperiorobliquerotatestheeyedownwardandoutward.Theinferiorobliquerotatestheeyeupwardandoutward.)
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Pupil and Aqueous Humor
⬤ Pupil: ➢ Dilates (mydriasis) when focusing on distant figure
or darkness ➢ Constricts (miosis) in extreme light
⬤ Aqueous humor provides the nutrients and oxygen to maintain lens and cornea
11
• Theaqueoushumoralsokeepstheeyemoistsothattheeyemaintainsitsshape.
• Whenfocusingonadistantfigureortryingtoseeinthedark,thepupiloftheeyedilates(mydriasis),allowingmorelighttoenter.Whentheeyeisexposedtoexcessivelight,thepupilconstricts(miosis).
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Aqueous Humor
⬤ Aqueous humor: ➢ Accumulates; must be released to maintain
pressure ➢ Canals of Schlemm: Ducts used to release
aqueous humor ⬤ Retina contains nerve endings to transmit
electrical impulses to brain
12
• Aftertheaqueoushumormovesacrossthelens,throughthepupil,andintotheanteriorchamber,itdrainsoutoftheeyethroughsmallopeningsnearthescleraandcornea.
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Vision
⬤ Retina contains rods and cones responsible for vision
⬤ Rods: Sight in dim light; produce black and white images
⬤ Cones detect color ⬤ Rods and cones synapse with nerve endings;
signals sent through optic nerve to brain ⬤ Occipital lobe: Visual interpretation
13
• Theeyesfocusincominglightandareresponsibleforsendingnerveimpulses,triggeredbyfocusedlight,tothebrainforinterpretation.
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Conditions That Affect the Eye
⬤ New developments/treatments: ➢ Laser surgery to correct vision ➢ Lens implantation used for blindness
⬤ Conditions: Glaucoma, conjunctivitis, congestion of eye, and viral and bacterial infections
14
• Lasersurgerycorrectsvisionbychangingtheshapeoftheeye.• Oftheconditionslisted,glaucomaistheonlyonethatisnotcontagious.Name
twoothernoncontagiouseyeconditions.(Colorblindnessandblindnessaretwoothernoncontagiouseyeconditions.)
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Allergic Conjunctivitis
⬤ With allergies, eyes become itchy, red, and watery
⬤ Seasonal allergies are most common ⬤ Treatment includes: Avoiding irritants, getting
allergy shots, mast cell stabilizers, antihistamines, and decongestants
15
• Manyoftheallergyremediesareover-the-counterdrops.
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Drug Treatment for Allergies
⬤ Mast cell stabilizers: Prevent allergy cells from opening and releasing chemicals that cause inflammation
⬤ Solutions, suspensions, and systemic agents ⬤ Antihistamines and decongestants alleviate
symptoms and inflammation ⬤ Corticosteroids relieve inflammation
16
• RefertoTable24-2(p.610).
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Ophthalmic Inflammation Caused by Infection or Injury
⬤ Corticosteroids are effective treatment ⬤ Forms include solutions, suspensions, and
ointments ⬤ Side effects: Temporary burning sensation,
blurred vision, eye pain, and headaches ⬤ Nonsteroidal antiinflammatory drugs (NSAIDs)
inhibit cyclooxygenase (COX)
17
• Theseagentsshouldnotbeusedanylongerthannecessarybecausetheymaycompromisetheeffectivenessoftheimmunesystem,resultinginaslowerrateofhealing.
• Prostaglandinsaredirectlyrelatedtothemechanismsresponsibleforinflammationandthepainassociatedwithit.\
• OphthalmicNSAIDssuchasflurbiprofen(Ocufen)andketoprofen(Acular)areavailableinsolutionformulationsonly.
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Bacterial Ophthalmic Infections
⬤ Conjunctivitis, known as “pink eye” ➢ Is common in daycare centers; contagious ➢ Is acute inflammation of the conjunctiva
⬤ Causes: Viral, bacterial, fungal, and allergies ⬤ Symptoms: Inflammation, itching, burning, and
white mucus ⬤ Wash hands and avoid touching the eyes
18
• Conjunctivitisisthemostcommoneyeinfectionthataffectschildren.
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Drug Treatments for Conjunctivitis
⬤ No treatment for viral infection; antibiotics for bacterial infection
⬤ Antiinfectives: Vidarabine, natamycin, gentamicin, and ciprofloxacin
⬤ Ophthalmic sulfonamides ⬤ Aminoglycosides ⬤ Tobramycin is the generic name for Tobrex, which is an aminoglycoside
ophthalmic preparation.
⬤ Macrolides
19
• Patientsarecounseledbythepharmacistinthepropertechniqueforadministeringeyedrops,inparttoavoidcontaminatingthemedication.Inaddition,mostmedicationsshouldnotbeinstilledintotheeyeswhileoneiswearingcontactlenses.Solutionsandointmentsdonotrequireshaking.
• Severalagentscanbeusedtotreatallergicconjunctivitis,suchasmastcellstabilizers,antihistamines,anddecongestants.
• Theprimaryophthalmicagentforsuperficialfungaleyeinfectionsisnatamycin,afungicidalagent.Azithromycinandciprofloxacinareantibacterialagents,whereastrifluridineisanantiviraldrug.
West Los Angeles College
Viral and Fungal Ophthalmic Infections
⬤ Viral: Herpes simplex, keratitis, and viral conjunctivitis ➢ Conditions are more common in those who are
immunocompromised ➢ Side effects: Light sensitivity, stinging, and mild
burning sensation ⬤ Fungal: Primary ophthalmic agent for
superficial fungal eye infections is natamycin
20
• Theaimofantiviraltherapyistointerruptoralterthesynthesisofnewvirusesataspecificstepduringreplication.
• Thespecificmethodofactionofnatamycininvolvesdrugbindingtothecellmembraneofthefungus.
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Glaucoma
⬤ Pressure within the eyes is higher than normal (intraocular pressure [IOP])
⬤ Two causes: Overproduction of aqueous humor; blocked ducts that drain excess aqueous humor
⬤ Left untreated, causes blindness ⬤ Types of glaucoma include primary, acute
congestive, and chronic simple
21
• Whatarethepossiblecausesofglaucoma?(Geneticdefects,certaineyeconditions[suchasuveitis],cataractextraction,andcorticosteroiduseareallpossiblecausesofglaucoma.)
• Xalatanophthalmicshouldbestoredintherefrigeratoruntilopened.• XalatanandLumigancancauseapermanentchangeineyecolor,thickening
anddarkeningofeyelashes,anddarkeningofeyelids.• Fiveclassificationsofdrugscanbeusedtotreatglaucoma:beta-adrenergic
blockers,carbonic-anhydraseinhibitors,cholinergicagonists(miotics),sympathomimetics,andprostaglandinanalogs.
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Drug Treatments for Glaucoma
⬤ Beta-adrenergic blockers lower IOP ⬤ Carbonic anhydrase inhibitors ⬤ Miotics reduce IOP ⬤ Sympathomimetics decrease aqueous humor ⬤ Prostaglandin agonists increase outflow of
aqueous humor
22
• Itisimportantthatthecorrectglaucomadiagnosisismadebecausethemedicationsareveryspecificintheiractions.
• Thereforeanincorrectdiagnosismeansthatthedrugsprescribedcouldbeineffectiveand/ordangerous.
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Miscellaneous Ophthalmic Agents
⬤ Artificial tears bought over the counter (OTC) ⬤ Used to relieve dry eyes, irritation ⬤ Ingredients include sodium chloride, buffers to
adjust pH, and additives to prolong effects ⬤ Dosage form is solution ⬤ Comes in various strengths and combinations
23
• Restasishelpsalleviatechronicdryeyescausedbyinflammation.• Allophthalmicpreparationshavethepossibilityofcausingeyeirritation
sincetheyareinstilledintotheeye.• Anagentthatcanbeusedforseveredryeyeiscyclosporine(Restasis)eye
drops.Restasishelpsalleviatechronicdryeyescausedbyinflammation.AgentssuchasartificialtearsarecommonlypurchasedOTCforthetreatmentofdryeye.
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The Ears (Auditory System)
⬤ Human ear responsible for hearing, balance, equilibrium, and communication skills
⬤ Ear is composed of three sections: External, middle, and inner
⬤ External ear contains auricle: Composed of cartilage and skin; entrance for sound waves
24
• Ifequilibriumisnotmaintainedbetweentheairpressureinsideandoutsidetheear,paincanresult.
• Whenmighttherebeanairpressuredifferencethatwouldrequiretheeustachiantubeintheeartoequilibratethetwopressurelevels?(Changingaltitudeswhentravelinginplanesandcarscancauseapressuredifferencethatwouldrequiretheeustachiantubetoacttoequilibratethem.)
• Thehumanearisnotonlyresponsibleforhearing,butitisalsoresponsibleforbalanceandmaintainingequilibrium.
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Anatomy of the Ear
25From Potter PA, Perry AG: Fundamentals of nursing, ed 8, St Louis, 2013, Mosby.
West Los Angeles College
External Ear
⬤ Auditory canal: About 1 inch long; leads to tympanic membrane (eardrum)
⬤ There are two major functions of tympanic membrane: Protection of middle ear from foreign objects; transmission of sounds to middle ear
⬤ Sounds transmitted by vibrations ⬤ Cerumen is wax substance produced by gland
26
• Thetympanicmembraneismadeoftissuesimilartoskin.• Thetympanicmembraneisathinmembranethatseparatestheexternalear
fromthemiddleearandisalsoknownastheeardrum.
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Middle Ear
⬤ Vibration carried to middle ear ⬤ Cavity (space) contains bony structures
(ossicles): Malleus (hammer), incus (anvil), and stapes (stirrup)
⬤ Ossicles are connected to each other ⬤ Eustachian tube:
➢ Leads to nasopharynx ➢ Equalizes pressure between outside and inside
atmosphere
27
• Themalleus,incus,andstapes(pronouncedSTAY-peas)alsoareknownasthehammer,anvil,andstirrup.Thesethreebonesareconnectedtoeachotherandarecollectivelyknownasossicles.
• Whatisthefunctionofthesebones?(Theossiclestransmitsoundwavesfromthemiddleeartotheinnerear.)
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Inner Ear
⬤ Stapes continues the transfer of sound to the inner ear
⬤ Fluid-filled cavity called the labyrinth; composed of many components that process and transmit audible sounds via nerve impulses to brain
⬤ There are two areas: Perilymph and membrane division
⬤ Cochlea ⬤ Vestibule ⬤ Semicircular canal
28
• Thecochleaiscoiledandhasthreefluid-filledcanalsinwhichsmallhairlikestructuresconnecttothenervethattransfersinformationtothebrain.
• Assoundwavesenterthecochlea,thehairsbendandcreateimpulsesthataretransmittedtothenerve.
• Thevestibuleisresponsibleforequilibriumandbalance,monitoredbyhairlikecellsthatareaffectedbygravitywhenmoved.
• Thisinformationgiveshumansasenseofdirectionandorientation.
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Common Conditions Affecting the Ear
⬤ Various conditions affect quality of hearing: Infections, earwax accumulation, damage to eardrum, and genetic defects
⬤ Most infections are viral but may lead to bacterial infection as well
29
• Thelackoftreatmentcanleadtohearingloss.• Variousconditionscanaffectthequalityofhearing,includinginfections,
swimmersear,earwaxaccumulation,anddamagetotheeardrum,aswellascongenitaldefectsoftheanatomyoftheear.
• DebroxandCeruminexareusedtoremoveearwax,andPinnacaineisusedforpain.
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Otitis Media
⬤ Otitis media is infection of the middle ear associated with inflammation of eustachian tube
⬤ Sore throat can lead to middle ear infection; often seen in children
⬤ For recurrent infections, insertion of small tubes by physicians to drain middle ear
30
• Asorethroatcanleadtoamiddleearinfectionbecausetheliningofthemiddleearandthenasopharynxformasinglecontinuousmembranousstructure.
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Drug Treatments for Otitis Media
⬤ Antiinfectives: Treat infection ⬤ Antibiotics if infection is severe – Amoxicillin or
trimethoprim-sulfamethoxazole ⬤ Antihistamines, decongestants, and
analgesics treat symptoms
31
• Childrenwhohaveexcessiveinfectionsmayneedtohavetubesplacedinthetympanicmembranetoallowdrainage.
• AntipyrineandbenzocainearethegenericnamesforAuralgan.
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Cerumen Buildup
⬤ Excessive wax builds up or dries, which impedes hearing quality
⬤ Doctor removes wax buildup ⬤ Irrigation kit includes saline solution and ear
syringe ⬤ Other treatments: Mineral oil, glycerin, or
hydrogen peroxide in the ear to soften the wax
32
• Waxisanaturalprotectivebarriertooutsideinfections.• Theexcessiveproductionmayleadtoimpairedhearing.
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Drug-Induced Ototoxicity
⬤ Ototoxicity caused by some drugs ⬤ Tinnitus (buzzing or ringing in ears) if
untreated leads to permanent ear damage ⬤ Balance may also be affected ⬤ Prognosis: Some cases reverse themselves;
others cause permanent hearing loss ➢ No treatment once hearing loss has occurred
33
• Ototoxicityoccurswhenthereiseardamagefrommedicationswithinthecochlearhaircells.
• Tinnitusisaringingorbuzzingintheears.
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Nose and Sinuses
⬤ The upper respiratory system is composed of nose and nasal cavities ➢ Pharynx and larynx
⬤ Cilia: Hairlike structures act as protection for nose
34
• Thenosealsofunctionsasthesensoryorganforthesenseofsmellandactsasadrainagesystemfortearsfromtheeye.
• Theeyesandearsareimportantsensoryorgans.Thenosealsofunctionsasthesensoryorganforthesenseofsmellandactsasadrainagesystemfortearsfromtheeye.
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Allergic Rhinitis
⬤ Itchy eyes ⬤ Runny nose ⬤ Sneezing ⬤ Congestion ⬤ Postnasal drip
35
• MostproductsareOTCforthiscondition.
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Bacterial Sinusitis
⬤ Infection of sinuses and inflammation of the nose/nasal passages
⬤ Symptoms: Nasal congestion, nasal discharge, cough, sinus pressure, headache, and fever
⬤ Treatment: Rest and fluids; saline irrigation ⬤ Drug treatment: Antibiotic therapy (amoxicillin,
doxycycline, clarithromycin, azithromycin, and trimethoprim-sulfamethoxazole), analgesics, decongestants, and antihistamines
36
• Distinguishingbetweenviralandbacterialsinusitiscanbedifficult.• Becauseviralsinusitisimprovesafter7to10days,adiagnosisofacute
bacterialsinusitisgenerallyismadeifthesesymptomshavecontinuedforlongerthan10daysorifsymptomscontinuetoworsenafter5to7days.
• Acutebacterialsinusitismostcommonlydevelopsasasecondaryinfectionafteraviralinfectionoftheupperrespiratorytract.Symptomsofbacterialsinusitisincludenasalcongestion,nasaldischarge,cough,sinuspressure,headache,andfever.Distinguishingbetweenviralandbacterialsinusitiscanbedifficult.Becauseviralsinusitiswillimproveafter7to10days,diagnosisofacutebacterialsinusitisisgenerallymadeifthesesymptomshavecontinuedforlongerthan10daysorifsymptomshavecontinuedtoworsenafter5to7days.
• Amoxicillinisconsideredfirst-linetherapyforbacterialsinusitisbecauseofitslowcostandnarrowantimicrobialspectrum.
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Strep Throat and Tonsillitis
⬤ Abrupt onset of throat pain, fever, and exudate from tonsils
⬤ Antibiotics: Reduce duration/severity of symptoms, incidence of complications, and bacterial transmission
⬤ Treatment: Adequate rest and hydration; saltwater gargles
⬤ Drug treatment: Penicillin, ampicillin, amoxicillin, cephalosporins, macrolides, and clindamycin; analgesics, lozenges, numbing sprays, and pain strips
37
• Asnotedpreviously,thereisariskofveryrarecomplicationsassociatedwithsuchinfections,includingrheumaticfeverandglomerulonephritis(aformofkidneydamage).
• Thegoalsofantibiotictreatmentforstrepthroataretoreducethedurationandseverityofsymptoms,reducetheincidenceofcomplications(e.g.,rheumaticfever),andreducethetransmissionofthebacteriatoclosecontacts.
• Antibioticprescriptionsforacuteinfectionsmustbetakenuntilgonetoavoidthedevelopmentofresistantstrains.
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Gastroesophageal Reflux Disease
⬤ Occurs when upper sphincter of the stomach relaxes
⬤ Risk factors: Obesity, smoking, and pregnancy ⬤ Full recovery is possible ⬤ Treatment: Avoid trigger foods, raise head of the
bed, and surgery (if medication and diet don't work) ⬤ Drug treatment: Antacids, histamine-2 antagonists,
and proton pump inhibitors (PPIs)
38
• Thisallowsacidiccontentsfromthestomachtobackupintotheesophagus,whichcanresultinaburningsensationinthechestorthroat.
• Ifleftuntreated,gastroesophagealrefluxdisease(GERD)canresultinsignificantdamagetothethroat.
• AvoidingfoodsthatbringaboutsymptomsofGERDisanimportantaspectoftreatment.Inadditiontoantacids,H
2-antagonistsandPPIsareusedtotreat
GERD.AllthreeclassesofthesemedicationsareavailableOTC,butsomeH2-
antagonistsandPPIsrequireaprescription.• Protonpumpinhibitors(PPIs)areatypeofagentusedforthetreatmentof
GERD.• AllthreemedicationsareavailableOTCandbyprescription.Theusualdose
ofPrevacidis15to30mgeveryday(qd),Prilosecis20mgqd,andZantacis150mgtwicedaily(bid).AlthoughPrilosecandPrevacidneedtobetakenbeforemeals,Zantaccanbetakenwithoutregardtomeals.
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