Mydriatics and cycloplegics: Nursing pharmacology
Introduction0:00–0:50
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.
Mechanism of action0:50–1:17
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.
Side effects1:17–1:35
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.
Contraindications and cautions1:35–1:44
Nursing considerations & client education1:44–3:15
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.
Assist your client as necessary to make sure they’re comfortable. Next, let your client know that they could feel some stinging when the eye drops are applied.
Then, lightly pull down on the skin below your client’s eye, and administer the prescribed number of drops into the center of the conjunctival sac.
Be sure to avoid getting drops directly on the cornea or touching your client’s eye with the tip of the dropper. Then, ask your client to close their eyes in order to help the medicine distribute evenly and aid with absorption.
Next, ask them to gently apply pressure over the eyelid above the lacrimal duct in order to help prevent systemic absorption.
After instillation, the medication will help provide comfort during the procedure, and will make it easier for the ophthalmologist to examine the eye.
After their procedure, stress the importance of avoiding scratching or rubbing their affected eye. Finally, let them know that the medication will make their vision blurry and more sensitive to light, and advise them to avoid driving and to wear sunglasses until the medication wears off.
Alright, as a quick recap…. Mydriatics and cycloplegics are applied topically to aid in various ophthalmologic exams and procedures.
Review3:15–3:49
Mydriatics cause dilation of the pupil by acting on the iris dilator muscle, while cycloplegics work by paralyzing the ciliary muscle of the eye, leading to a loss of accommodation.
Nursing considerations when caring for a client receiving a mydriatic and cycloplegic medication include proper administration, promotion of the client’s safety and comfort, as well as providing client education about recognizing and managing side effects such as photophobia and blurred vision.
| 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 |
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| INDICATIONS |
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| ROUTE(S) OF ADMINISTRATION |
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| SIDE EFFECTS |
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| CONTRAINDICATIONS AND CAUTIONS |
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| NURSING CONSIDERATIONS |
Client education
Administration
Monitoring
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Author: Maria Emfietzoglou, MD
Illustrator: Robyn Hughes, MScBMC
- "Focus on Nursing Pharmacology" LWW (2019)
- "Pharmacology" Elsevier Health Sciences (2014)
- "Mosby's 2021 Nursing Drug Reference" Mosby (2020)
- "Saunders Comprehensive Review for the NCLEX-RN Examination" Saunders (2016)
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