Pharmacology of Eye and Ear Medications

Indication:
- Used in eye exams.
- Treats uveal tract inflammatory sites.
Mechanism of Action (MOA):
- Relaxes muscles in the eye to prevent mydriasis for prolonged periods of time.
- Causes dilation of the pupils (mydriasis).
Adverse Effects:
  - Photosensitivity.
  - Anticholinergic effects:
    - Blurred vision.
    - Urinary retention.
    - Dry mouth.
    - Constipation.
Client Education:
- Effects can last for 7-10 days.
- Recommend wearing sunglasses to mitigate photosensitivity.

Classification:
- Second-line drug for Primary Open-Angle Glaucoma (POAG).
Mechanism of Action (MOA):
- Decreases intraocular pressure (IOP) indirectly by inducing ciliary muscle contraction.
Adverse Effects:
-BLURRED VISION- USE GOOD LIGHTING
  - Retinal detachment.
  - Parasympathetic effects:
    - Bradycardia.
    - Increased salivation.
    - Sweating.
    - Flushing.
    - Pupil constriction (miosis).

  - Hypotension.
  - Bronchospasm.
Contraindications:
- Pregnancy.
- Caution in patients with asthma due to risk of bronchospasm.

Examples:
  - Apraclonidine.
  - Brimonidine tartrate (first-line against POAG).
  - Dipivefrin hydrochloride.
Mechanism of Action (MOA):
- Reduces IOP by limiting the production of aqueous humor and increasing its outflow. DILATES THE PUPIL
Adverse Effects:
  - Photosensitivity.
  - Stinging/itching.
  - Dilated pupils.
  - Blurred vision.
  - Headache.
  - Dry mouth.
  - Reddened sclera.
  - Hypotension/drowsiness.
Client Education/Nursing Actions:
  - WEAR SUNGLASSES to help with photosensitivity.
  - Report any adverse effects immediately.
  - Monitor blood pressure.
  - Avoid rubbing the eyes.
  - Caution advised while driving; inform healthcare provider of dizziness.
  - If wearing soft contacts, remove them and refrain from re-inserting for at least 15 minutes after administering medication.
Contraindications:
- Pregnancy.
Interactions:
- MAOIs can lead to hypertensive crisis.
- Antihypertensives may increase the risk of hypotension.

Classification:
- Non-selective beta-blocker primarily used for treating POAG and closed-angle glaucoma in emergency situations.
Mechanism of Action (MOA):
- Decreases IOP by reducing the amount of aqueous humor produced.
Adverse Effects:
  - Temporary stinging discomfort.
  - BRONCHOCONSTRICTION.
  - HYPOGLYCEMIA
  - Bradycardia.
  - Hypotension.
Contraindications:
  - Respiratory diseases (risk of bronchospasm).
  - Sinus bradycardia and heart block.
  - Heart failure.
Interactions:
- Increased cardio and respiratory risks with oral beta blockers and calcium channel blockers.
- May interfere with insulin effects.

Classification:
- First-line medication for POAG and ocular hypertension.
Mechanism of Action (MOA):
- Reduces IOP by increasing the rapid outflow of aqueous humor through relaxation of the ciliary muscle.
- Dilates vessels in the trabecular meshwork.
Adverse Effects:
  - Bulging of ocular blood vessels.
  - Permanent brown pigmentation of the iris.
  - Stinging/burning/red eyes.
  - Blurred vision.
  - Migraines.
Client Education:
  - Check for corneal abrasions; do not administer if the eye is not intact.
  - Brown pigmentation of the iris is a permanent change.
  - Advise against rubbing the eyes.
Contraindications:
- Pregnancy.

Indication:
- Treatment of vertigo associated with inner ear issues.
Mechanism of Action (MOA):
- Exhibits both antihistamine and anticholinergic effects.
Adverse Effects:
- Sedation.
- Anticholinergic effects.
Client Education/Nursing Actions:
- Be aware of sedative effects and do not drive until the effects on them are known.

Patient Positioning:
- Client should sit upright or lie supine, tilting their head slightly and looking upward toward the ceiling.
Administration Steps:
  - Rest your dominant hand on the client's forehead.
  - Hold the dropper above the conjunctival sac approximately 1 to 2 cm away.
  - Drop the medication into the sac, avoiding direct contact with the cornea.
  - Instruct the client to close their eyes gently.
  - If they blink during instillation, repeat the procedure.
  - Apply gentle pressure on the nasolacrimal duct with a clean tissue for 30 to 60 seconds to prevent systemic absorption of the medication.
  - If instilling multiple medications in the same eye, wait at least 5 minutes between each.
  - For eye ointment, apply a thin ribbon along the edge of the lower eyelid from the inner canthus to the outer canthus.

Patient Positioning:
- Client should sit upright or lie on their side.
Administration Steps:
  - Straighten the ear canal by pulling the auricle upward and outward for adults, or downward and backward for children under 3 years.
  - Hold the dropper 1 cm above the ear canal and instill the medication.
  - Gently apply pressure with your finger to the tragus of the ear unless it is too painful.
  - Do not press cotton balls deeply into the ear canal; if needed, gently place them in the outermost part only.
  - Have clients remain in the side-lying position for at least 2 to 3 minutes after instilling ear drops.

Tip for Drop Administration:
- Drops may be warmed in hands before administration as cold drops may cause dizziness.