Pharm Chapter 57: Ophthalmic Drugs

A client is prescribed epinephrine eye drops for treatment of chronic open-angle glaucoma. The client complains of burning with instillation of the drops. Which statement is the nurse's best response? a. "This is a typical adverse effect and may lessen over time." b. "It is a normal sensation because the eye drops reduce inflammation." c. "This will occur if the drop is not placed in the correct area of the eye." d. "That should not occur. Contact your health care provider immediately."

a. "This is a typical adverse effect and may lessen over time." Both epinephrine and dipivefrin are used to reduce elevated intraocular pressure in the treatment of chronic open-angle glaucoma, either as initial therapy or as long-term therapy. Adverse effects of the sympathomimetic mydriatics are primarily limited to ocular effects and include burning, eye pain, and lacrimation. Such effects are usually temporary and may subside as the client grows accustomed to the medication.

The nurse is educating a client with a new diagnosis of open-angle glaucoma on the adverse effects of the indirect-acting miotic eye drops prescribed. What will the nurse include in the teaching as possible adverse effects? (Select all that apply.) a. Blurred vision b. Farsightedness c. Paralysis of eyelids d. Stinging on instillation e. Decreased nighttime vision

a. Blurred vision d. Stinging on instillation e. Decreased nighttime vision Adverse effects are more likely to occur with indirect-acting miotics because they have longer lasting effects. Effects include blurred vision, drug-induced myopia (nearsightedness), and accommodative spasms. Such effects are secondary to contraction of the ciliary muscle. Miotic drugs also cause vasodilation of blood vessels supplying the conjunctiva, iris, and ciliary body, which may lead to vascular congestion and ocular inflammation. Other undesirable effects include temporary stinging upon drug instillation, reduced nighttime or low-light vision, conjunctivitis, lacrimation (tearing), twitching of the eyelids (blepharospasm), and eye or eyebrow pain.

A child born with increased intraocular pressure is likely to be diagnosed with which type of glaucoma? a. Congenital b. Pigmentary c. Open angle d. Angle closure

a. Congenital An infant may be born with congenital glaucoma.

Parasympathomimetic ophthalmic drugs such as pilocarpine (Pilocar) reduce intraocular pressure in the treatment of glaucoma by which mechanism of action? a. Miosis b. Mydriasis c. Cause the pupils to get larger d. Decrease in drainage of aqueous humor

a. Miosis Pilocarpine is a direct-acting parasympathomimetic drug that is used as a miotic in the treatment of open-angle glaucoma. Miosis causes pupillary constriction, increasing the outflow of aqueous humor.

Sympathomimetic mydriatics have the potential to react with other drugs if sufficient topical absorption occurs. When given concurrently, drugs in which class may interact with the sympathomimetic mydriatics? a. Thyroid hormones b. Oral contraceptives c. Calcium channel blockers d. Nonsteroidal antiinflammatory drugs

a. Thyroid hormones With sufficient topical absorption, sympathomimetic mydriatics have the potential to react with other drugs. Cardiac dysrhythmias are potentiated when mydriatic drugs are given with halogenated anesthetics, cardiac glycosides, thyroid hormones, or tricyclic antidepressants.

Which statement by a client indicates a need for further teaching regarding proper administration of eyedrops? a. "I will be careful not to touch my eye with the dropper." b. "I will rinse the eyedropper with tap water after each use." c. "I will press gently against the inner corner my eye after I administer the eye drops." d. "I will wash my hands thoroughly with soap and water before putting in the eye drops."

b. "I will rinse the eyedropper with tap water after each use." It is important to maintain sterility of the eyedrop container; therefore, it should not be rinsed. The cap should be put immediately back on the container.

The nurse is providing education to a client with a diagnosis of bilateral conjunctivitis (pink eye) who is prescribed sulfacetamide (Bleph-10). What information in the client history is MOST important and should be reported immediately to the health care provider? a. The client does not like eyedrops b. The client is allergic to sulfa drugs. c. The client has never had pink eye before. d. The client wears colored soft contact lenses.

b. The client is allergic to sulfa drugs. The other data are important for education and teaching; however, a client allergic to sulfa drugs should not be prescribed a sulfa drug for treatment. The health care provider would need to be alerted immediately.

The client is prescribed olopatadine (Patanol) for treatment of allergic conjunctivitis. The nurse knows the medication works though which action? a. Inhibits release of mast cells b. Lubricates the surface of the eye c. Competes at histamine receptor sites d. Stimulates the dilator muscle to contract

c. Competes at histamine receptor sites Patanol is an ocular antihistamine and works by competing at histamine receptor sites.

The nurse is educating a client who was administered atropine sulfate solution for an eye examination. The nurse includes which information in the education? a. Instruct that a common adverse effect is dry eyes. b. Instruct to wait 72 hours to wear contact lenses. c. Encourage use of sunglasses to decrease sunlight sensitivity. d. Advise that pupils may remain small for 12 hours after administration.

c. Encourage use of sunglasses to decrease sunlight sensitivity. The medication is a mydriatic and is used to dilate the pupils for eye exams. The client may have increased sunlight sensitivity and should wear sunglasses until the pupils return to normal size.

At the time of birth, infants are often treated with erythromycin eye ointment as prophylactic treatment against what possible organism? a. Candida albicans b. Malassezia furfur c. Aspergillus fumigatus d. Neisseria gonorrhoeae

d. Neisseria gonorrhoeae Erythromycin eye ointment is indicated for the treatment of neonatal conjunctivitis caused by Chlamydia trachomatis and for the prevention of eye infections in newborns that may be caused by N. gonorrhoeae or other susceptible organisms.

Antimicrobials

• A variety of infections can occur in the eye; many are self- limiting. Topical antimicrobials used to treat ocular infections include antibacterial, antifungal, and antiviral drugs. • Topical antimicrobials used to treat infections of the eye work to destroy the invading organism; actions are similar to those described for systemically administered drugs. • Ocular antimicrobials are used for known or suspected infection with one or more specific microorganisms. Empiric treatment is based on clinical evaluation of presenting symptoms. • The most common adverse effects of ocular antibiotics are local and transient inflammation, burning, stinging, urticaria, dermatitis, angioedema, and drug hypersensitivity. • Concurrent use of antibiotics and corticosteroids may interact. Corticosteroids have immunosuppressive effects that may impede the therapeutic effects of ocular antimicrobials. • A large proportion of the inflammatory diseases of the eye are caused by viruses, and many ocular antimicrobials are available to treat bacterial, viral, and fungal infections of the eye. Common infections include conjunctivitis, hordeolum, keratitis, uveitis, and endophthalmitis.

Anti-inflammatory Drugs

• Anti-inflammatory ophthalmic drugs include corticosteroids and are used to inhibit inflammatory responses to mechanical forces, chemicals, and immunologic reactions. • Anti-inflammatory drugs used systemically may also be used ophthalmically to treat various ocular inflammatory disorders and ocular surgery-related pain and inflammation. These drugs include both nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids. • Corticosteroids and NSAIDs are applied topically for symptomatic relief of many ophthalmic inflammatory conditions and may be used to treat corneal, conjunctival, and scleral injuries from chemical, radiation, or thermal burns or from penetration of foreign bodies during acute phases of the injury to prevent fibrosis and scarring, which result in visual impairment. • The most common adverse effect of corticosteroids is transient burning or stinging. Extended use may result in cataracts, increased intraocular pressure, and optic nerve damage.

Diagnostic Drugs

• Atropine sulfate solution and ointment are used as mydriatic and cycloplegic drugs. It is used to assist in eye examination or to treat uveal tract inflammatory states. • Cyclopentolate solution (Cyclogyl) is used as a diagnostic mydriatic and cycloplegic drug. • Fluorescein is a diagnostic dye used to identify corneal defects and foreign objects.

Cholinergic Drugs (Miotics)

• Direct-acting cholinergics include acetylcholine, carbachol, and pilocarpine. • Indirect-acting drugs, which are also called cholinesterase inhibitors, include echothiophate, the only available drug. Since the primary effect is pupillary constriction, or miosis, they are also commonly called miotics. • Acetylcholine is the neurochemical mediator of nerve impulses in the parasympathetic nervous system, stimulating parasympathetic or cholinergic receptors resulting in several effects on the eye: miosis, vasodilation of blood vessels in and around the eye, contraction of ciliary muscles, drainage of aqueous humor, and reduced intraocular pressure. • Ciliary muscle contraction promotes aqueous humor drainage by widening the space where the drainage occurs. Miosis promotes aqueous humor drainage by causing the iris to stretch, which also serves to widen this space. • Direct- and indirect-acting miotics have effects similar to those of acetylcholine, but their actions are more prolonged. • The direct- and indirect-acting miotics are used for treatment of open-angle glaucoma, angle-closure glaucoma, and convergent strabismus ("cross-eye") and in ocular surgery. • Most adverse effects from the use of cholinergics and cholinergic inhibitors are local and limited. Adverse effects are more likely with indirect-acting miotics because they are longer-lasting. Effects include blurred vision, drug-induced myopia (nearsightedness), and accommodative spasms.

Nursing Process

• Document any redness, swelling, pain, excessive tearing, eye drainage or discharge, decrease in visual acuity, or other unusual symptoms. • Focus the nursing history on past or present systemic disease processes and exposure to any chemicals that could be topical irritants to the eye, skin, or mucous membranes, including past or present occupational and environmental exposures. • Always inspect the solution, and administer only clear, unexpired products (e.g., drops, ointments, and solutions) to the eye. • Administer all ophthalmic preparations exactly as ordered. Always apply into the conjunctival sac. Safe and accurate application or instillation technique also includes avoiding contact of the eyedropper or tube to the eye to prevent contamination of the drug. • Applying pressure to the inner canthus after instillation of medication is needed to prevent or decrease systemic absorption and subsequent systemic adverse effects. • With abrasion or injury to the eye and appropriate medications, patching the affected eye is used to prevent further injury resulting from loss of blink reflex due to topical anesthetic. • Patients need to report any increase in symptoms, such as eye pain or drainage and fever. • Therapeutic responses to miotics include decreased aqueous humor of the eye with resultant decreased intraocular pressure and signs, symptoms, and long-term effects of glaucoma. • Beta-adrenergic blockers are therapeutic if intraocular pressure decreases. Adverse effects include weakness, eye irritation, rash, bradycardia, hypotension, and dysrhythmias. • Therapeutic responses to antibiotic, antifungal, and antiviral ophthalmic drugs include elimination of infection or condition and complications and resolution of symptoms. • Therapeutic responses to ophthalmic anesthetics include prevention/relief of pain. • Adverse effects may include central nervous system excitation (e.g., dizziness, tremors, restlessness, and nervousness) if the drug is systemically absorbed. Anti-inflammatory ophthalmic solutions result in a decrease in allergic reactions with a decrease in itching, tearing, redness, and eye discharge. Potential complications of these solutions include swelling of the conjunctiva (chemosis).

Antiallergic Drugs

• Olopatadine (Patanol) is an ocular antihistamine used for allergic conjunctivitis (hay fever), which can be seasonal or nonseasonal. It works by competing at receptor sites for histamine, which produces ocular symptoms such as itching and tearing. Ocular antihistamines include azelastine (Optivar), emedastine (Emadine), ketotifen (Zaditor), and epinastine (Elestat). • Cromolyn sodium (Crolom), an antiallergic drug that inhibits release of inflammation-producing mediators from sensitized inflammatory cells, is used to treat vernal keratoconjunctivitis. • Tetrahydrozoline is an ocular decongestant, promoting vasoconstriction of blood vessels in and around the eye to reduce the edema associated with allergic and inflammatory processes. It is specifically indicated to control redness, burning, and other minor irritations. • An array of products is available over-the-counter to provide lubrication or moisture for the eyes. This is helpful to patients with dry or otherwise irritated eyes.

Carbonic Anhydrase Inhibitors

• Ophthalmic carbonic anhydrase inhibitors include brinzolamide (Azopt) and dorzolamide (Trusopt). These two drugs are available only in topical ophthalmic form. Both drugs are also sulfonamides and are chemically related to the sulfonamide antibiotics. They should be used with caution in patients who are allergic to sulfa antibiotics. • Carbonic anhydrase inhibitors work by inhibiting the enzyme carbonic anhydrase, which results in decreased intraocular pressure by reduction of aqueous humor formation. • Ocular carbonic anhydrase inhibitors are used primarily for management of glaucoma, both open-angle and angle- closure types, and may be used preoperatively to control intraocular pressure. • Patients with sulfa allergies may develop cross-sensitivities to carbonic anhydrase inhibitors.

Osmotic Diuretics

• Osmotic drugs may be administered either intravenously, orally, or topically to reduce intraocular pressure; glycerin and mannitol are most commonly used. • Osmotic diuretics reduce ocular hypertension by causing the blood to become hypertonic, creating an osmotic gradient that pulls water from the aqueous and vitreous humors into the bloodstream, causing reduced volume of intraocular fluid and decreased intraocular pressure. • Osmotic diuretics are used for acute glaucoma episodes and reduction of intraocular pressure before or after ocular surgery. Glycerin is used first; if unsuccessful, mannitol is tried. • Osmotic diuretics are contraindicated with allergy, anuria, acute pulmonary edema, cardiac decompensation, and severe dehydration because they can worsen all of these conditions. • The most frequent reactions to osmotic diuretics are nausea, vomiting, and headache. The most significant adverse effects are fluid and electrolyte imbalances.

Sympathomimetics (Mydriatics)

• Sympathomimetic drugs are used for the treatment of glaucoma and ocular hypertension. These drugs include alpha receptor agonists brimonidine (Alphagan P) and apraclonidine (Iopidine), and alpha and beta receptor agonists epinephryl (Epinal) and dipivefrin (Propine). • Sympathomimetic drugs mimic the neurotransmitters norepinephrine and epinephrine, stimulating dilator muscle contraction by alpha and/or beta receptor interaction resulting in mydriasis. • Both epinephrine and dipivefrin are used to reduce elevated intraocular pressure in the treatment of chronic open-angle glaucoma, either as initial therapy or as long-term therapy. Increases in intraocular pressure during surgery are usually mediated via increased catecholamine stimulation. • Adverse effects of the sympathomimetic mydriatics are primarily limited to temporary ocular effects and include burning, eye pain, and lacrimation.

Beta-Adrenergic Blockers

• The antiglaucoma beta-adrenergic blockers that reduce intraocular pressure include the beta1-selective drugs betaxolol and levobetaxolol. • The ophthalmic beta blockers reduce both elevated and normal intraocular pressure. They reduce intraocular pressure by reducing aqueous humor formation. • Ophthalmic beta blockers are used to reduce elevated intraocular pressure in chronic open-angle glaucoma and ocular hypertension. They may also be used alone or in combination with a topical miotic, which may have an additive intraocular pressure-lowering effect. • Adverse effects of beta blockers include transient burning and discomfort, blurred vision, pain, photophobia, lacrimation, blepharitis, keratitis, and decreased corneal sensitivity.

Prostaglandin Agonists

• The newest class of drugs used to treat glaucoma is the prostaglandin agonists, including latanoprost (Xalatan), travo- prost (Travatan Z), and bimatoprost (Lumigan). • Prostaglandins reduce intraocular pressure in glaucoma by increasing the outflow of aqueous humor between the uvea and sclera, as well as through the trabecular meshwork. • Prostaglandin agonists are well tolerated. Adverse effects include foreign body sensation, punctate epithelial keratopathy (dotted appearance of the cornea), stinging, conjunctival hyperemia, blurred vision, itching, and burning. Systemic effects occur infrequently. • In some people with hazel, green, or bluish-brown eye color, eye color will turn permanently brown, even after the medication is discontinued. • Concurrent administration of prostaglandin agonists with any other eyedrops containing the preservative thimerosal may result in precipitation.

Topical Anesthetics

• Topical anesthetics are used to prevent pain to the eye and are beneficial during surgery, ophthalmic examinations, and removal of foreign bodies. The two currently available topical anesthetics used for ophthalmic purposes are proparacaine and tetracaine. • Application of topical anesthetic drugs results in local anesthesia in less than 30 seconds; they are used to produce ocular anesthesia for short corneal and conjunctival procedures. • Adverse effects are rare with ophthalmic anesthetic drugs and are limited to local effects such as stinging, burning, redness, lacrimation, and blurred vision.

Antiglaucoma Drugs

•Treatment of glaucoma involves reducing intraocular pressure by either increasing the drainage of aqueous humor or decreasing its production. Some drugs may do both. -Drug classes used to reduce intraocular pressure include direct-acting cholinergics (also called miotics and parasympathomimetic drugs), indirect-acting cholinergics (also called miotics, cholinesterase inhibitors, and parasympathomimetic drugs), adrenergics (also called mydriatics and sympathomimetic drugs), antiadrenergics (beta blockers; also called sympatholytic drugs), carbonic anhydrase inhibitors, osmotic diuretics, and prostaglandin agonists. • The newest class of drugs used to treat glaucoma is the prostaglandin agonists. The four most commonly used drugs in this class include latanoprost (Xalatan), travoprost (Travatan-Z), bimatoprost (Lumigan), and tafluprost (Zioptan).