Lecture 04

Therapeutic Agents for the Eyes, Ears, Nose and Throat

Therapeutic Agents for the Eyes, Ears, Nose, and Throat

OBJECTIVES

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1. Describe the anatomy and physiology of the eyes, ears, nose, and throat.

2. List the primary signs and symptoms of common conditions associated with the eyes, ears, nose, and throat that are discussed in this chapter.

3. Recognize prescription and over-the-counter drugs used to treat common conditions discussed in this chapter.

4. Write the generic and trade names for the drugs discussed in this chapter.

5. List appropriate auxiliary labels when filling prescriptions for drugs discussed in this chapter.

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-cannot prescribe meds– Optometrists perform eye exams– Ophthalmologists are medical doctors

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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 and is not considered to be one of the four layers of the eyelid

• Orbit is bony socket that holds the eye• Eye position is 100 degrees of peripheral vision

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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

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Eye Anatomy

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From Potter PA, Perry AG: Fundamentals of nursing, ed 8, St Louis, 2013, Mosby.

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

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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

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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

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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

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Eye Muscles and Direction of Movement

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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

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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

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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• Mydriasis: dilation of the pupil

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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

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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

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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

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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)• Ketoprofen and flurbiprofen are ophtalmic NSAIDs

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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

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Drug Treatments for Conjunctivitis • No treatment for viral infection; antibiotics for

bacterial infection• Ophtalmic antibiotics should maintain sterility

and not be used with contact lenses in the eyes• Antiinfectives: Vidarabine, natamycin, gentamicin,

and ciprofloxacin• Ophthalmic sulfonamides• Aminoglycosides• Macrolides

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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

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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

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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 • Latanoprost (Xalatan)- Lumigan can permanently

change eye color, thicken and darken the lashes and eyelids. (Xalatan) must be refrigerated

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Miscellaneous Ophthalmic Agents • Artificial tears bought over the counter (OTC)• Used to relieve dry eyes, irritation

– Cyclosporine(Restasis)

• Ingredients include sodium chloride, buffers to adjust pH, and additives to prolong effects

• Dosage form is solution• Comes in various strengths and combinations

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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

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Anatomy of the Ear

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From Potter PA, Perry AG: Fundamentals of nursing, ed 8, St Louis, 2013, Mosby.

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

can affect quality of hearing

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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– Auralgan otic solution containing antipyrine and benzocaine

treats pain and congestion and swelling

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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

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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

• Debrox and Ceruminex medications for earwax removal

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Otitis Media • Otitis media is infection of the middle ear

associated with inflammation of eustachiantube

• 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

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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

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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

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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

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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

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Allergic Rhinitis

• Itchy eyes• Runny nose• Sneezing• Congestion• Postnasal drip

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Bacterial Sinusitis • Infection of sinuses and inflammation of the

nose/nasal passages• Acute bacterial sinusitis develops as a secondary

infection after an upper respiratory viral infection • 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

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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 until gone.

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Gastroesophageal Reflux Disease • Occurs when upper sphincter of the stomach

relaxes(GERD)• 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)– Zantac, Prilosec and Prevacid are available OTC

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Questions?

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