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Mydriatics and cycloplegics: Nursing Pharmacology

Notes

Notes

MYDRIATICS AND CYCLOPLEGICS
DRUG NAME
epinephrine, phenylephrine (Altafrin)
atropine (Isopto Atropine), cyclopentolate (Cyclogyl), homatropine (Homatropaire), scopolamine, 
tropicamide (Mydriacyl)
CLASS
Adrenergic agonists
Antimuscarinics
MECHANISM OF ACTION
  • Mydriatic effects: stimulation of the iris dilator muscle → pupillary dilation
  • Mydriatic effects: stimulation of the iris dilator muscle → pupillary dilation
  • Cycloplegic effects: paralysis of the ciliary muscle of the eye → loss of lens accommodation
INDICATIONS
  • Eye exams
  • Ophthalmic procedures
ROUTE(S) OF ADMINISTRATION
  • TOP: eye drops and ointments
SIDE EFFECTS
  • Dry eyes
  • Photophobia
  • Blurred vision
  • Systemic absorption: confusion, drowsiness, dry mouth, flushing, tachycardia, hypertension, constipation
CONTRAINDICATIONS AND CAUTIONS
  • Narrow-angle glaucoma
NURSING CONSIDERATIONS
  • Ensure medications are labeled with name, strength, amount, and expiration date

Client education
  • Purpose of medication:  provide comfort during the procedure; facilitate ophthalmologist examination of the eye
  • Drops may sting with application
  • Side effects: blurry  vision; increased sensitivity to light
    • Avoid light
    • Wear sunglasses
  • Avoiding scratching or rubbing the eye

Administration
  • Verify correct eye needing medication
  • Position client: leaning back and looking at the ceiling
  • Gently pull down on the skin below the eye
  • Administer the prescribed number of drops into the center of the conjunctival sac
  • Avoid getting drops directly on the cornea or touching the tip of the dropper to the eye
  • Ask the client to close their eyes and gently apply pressure over the eyelid above the lacrimal duct

Monitoring
  • Monitor for side effects and evaluate for the therapeutic response of the medication
Memory Anchors and Partner Content
Transcript

Mydriatics and cycloplegics are a group of medications that have various indications for use in ophthalmology, such as during eye exams or ophthalmic surgical procedures.

Mydriatics cause mydriasis, or pupil dilation; whereas cycloplegics cause cycloplegia, or paralysis of the muscles that are responsible for accommodation to focus on nearby objects.

Commonly used mydriatics include adrenergic agonist medications, such as epinephrine and phenylephrine, while some medications that act as both mydriatics and cycloplegics include antimuscarinic medications, such as atropine, cyclopentolate, homatropine, scopolamine, and tropicamide.

These medications are applied topically in the form of eye drops, or ophthalmic ointments. Once applied, these medications work by blocking acetylcholine from binding to cholinergic receptors.

Mydriatic effects can involve stimulation of the iris dilator muscle, which dilates the pupil; or inhibition of the iris sphincter muscle, which constricts the pupil, or both.

On the other hand, cycloplegic effects result in paralysis of the ciliary muscle of the eye, leading to a loss of accommodation of the lens to focus on nearby objects.

Unfortunately, mydriatics and cycloplegics can result in side effects, such as dry eyes, blurred vision, and photophobia. Less frequently, they might be absorbed systemically, and clients may experience confusion and drowsiness, as well as dry mouth, flushing, tachycardia, hypertension, and constipation.

Finally, the only contraindication for mydriatics and cycloplegics is that they should not be used in clients with narrow-angle glaucoma.

Okay, if a client with ophthalmic injury is prescribed a mydriatic and cycloplegic medication before an ophthalmologic procedure, start by assembling the sterile field and ensure the mydriatic and cycloplegic medication, as well as any other medications used in the procedure, are labeled with name, strength, amount, and expiration date.

Before administration, verify which eye has been prescribed the mydriatic and cycloplegic medication. Then, ask your client to lean back and look at the ceiling.

Sources
  1. "Focus on Nursing Pharmacology" LWW (2019)
  2. "Pharmacology" Elsevier Health Sciences (2014)
  3. "Mosby's 2021 Nursing Drug Reference" Mosby (2020)
  4. "Saunders Comprehensive Review for the NCLEX-RN Examination" Saunders (2016)