Pharmacology Flashcards
Drops: Advantages and Disadvantages
Advantages:
Targeted delivery
Generally well-tolerated
Reduced systemic side effects
Decreased Antibiotic resistance
Disadvantages:
Local irritation, toxic or allergic reactions
Some medications not well-absorbed
Duration in tear film less than 5 minutesOintments: Advantages and Disadvantages
Advantages:
Increase the contact time
Soothing to ocular surface
Disadvantages:
Blurring of vision
Limited availability of medications in ointment formPurposes of ocular medications
Diagnosis
Treatment of eye diseases
prevention of eye diseases
Prescription often required
Exceptions: (available over the counter)
Artificial tears (lubricating over the counter)
Ocular decongestants (decease eye redness)
Ocular medications are used to treat
Glaucoma
Infections
Other
Possible side effects of ocular medications
Redness Stinging Blurred vision Sensitivity to light Constriction or dilation of pupil Allergic reactions
How to properly use ocular medications
Wash your hands
Confirm that the patient is not allergic to the medicine (or preservative for medics, if applicable) that will be applied (review chart, question patient)
Check the expiration date
Shake the container
Tilt the patient’s head back and instruct them to look up
Gently pull the lower lid away from the eye, forming a pouch by the inferior fornix
Place one drop (1/4 to 1/2 inch of ointment) in the pouch; (Note: Do not touch the eye or eyelid with the container or dropper to avoid contamination)
For drops, instruct the patient to close his/her eye and press his/her finger against the inner corner of their eyelid and the side of their nose, in order to prevent the draining away; inform the patient of any possible side effects, e.g., burning, redness
For ointment, instruct the patient to close their eye; inform them to expect their vision to be blurry for a few minutes
Repeat with the other eye if required
Replace the cap or dropper n the bottle or tube and tighten
Topical Anesthetics and Diagnostic Agents
Among the most commonly used topical agents in an ophthalmology office
Used for ocular examination and minor procedures
Rapid onset of anesthesia generally last for 20-30 minutes
Topical (applied directly to a part of the body) anesthetics
May be used once or twice for ocular examination and treatment
Repeated use can damage the epithelium, impair healing, and even result in corneal melting
Patients should never be given topical anesthetic for use at home
Dyes for examination of the ocular surface
Fluorescein
Lissamine green and rose bengal
Fluorescein
Applied in the form of a solution or from sterile strips
Renders tear film visible to assess. quality and stability
Aids in applanation tonometry
Stains defects n the corneal and conjunctival epithelium
Lissamine green and rose bengal
Available as solutions or dye impregnated strips
Similar to fluorescein but stain devitalized cells
Useful in evaluating dry eye conditions
Lissamine green is less irritating than rose bengal
Commonly used anesthetic
Generic Name: Cocaine (1%-4%)
Generic name: Proparacaine (arcane, oculi-caine, ophthetic, paracaine) (0.5%)
Generic name: Tetracaine (Pontocaine) (0.5%, 1.0%, 2.0%)
Mydriatics and Cycloplegics
Very commonly used
Affect the autonomic innervation of the eyes to produce mydriasis (pupillary dilation) and cycloplegia (paralysis of accommodation)
Facilitate examination and testing
Therapeutic use for relief of photophobia associated with intraocular inflammation
Can induce angle closure, especially in some hyperopes
Check chamber depth before dilating a patient for the first time
Considerable variation in onset and duration based on underlying ocular conditions, age, eye color and other factors
Provide temporary sunglasses to patients
Advise caution with driving or operating machinery.
Common Mydriatics and cycloplegics
Phenylephrine (AK-dilate, Mydfrin, Neo-synephrine) (2.5%, 10%) (Onset: 30-60 min) (Duration: 3-5 hours)
Tropicamide (Mydriacyl, tropicacyl) (0.5%, 1.0%) (Onset: 20-40 min) (Duration: 4-6 hours)
Cyclopentolate (AK-Pentolate, cyclogyl, calate) (0.5%, 1.0%, 2.0%) (Onset: 30-60 min)(Duration: 6-24 hours)
Homatropine (Isopto Homatropine) (2%, 5%) (Onset: 30-60 min) (Duration: 3 days)
Scopolamine (Isopto Hyoscine) (0.25%) (Onset:30-60 min) (Duration: 4-7 days)
Atropine (Atropine-care, Isopto Atropine) (1.0%) (Onset: 45-120 min) (Duration: 7-14 days)
Ocular Anti-inflammatory medications
Inflammation is associated with infection, trauma, surgery, allergic/toxic reactions, and auto-immune diseases
Pain, redness and photophobia common indications of acute inflammation
Chronic Inflammation can lead to increased intraocular pressure, cataracts, and scarring
Steroids and non-steroidal anti-inflammatory medications (NSAIDs)
Combined with injectable/systmic meds for severe inflammation
Non steroidal Anti inflammatories (NSAIDs)
Non-specific; block specific inflammatory mediators
Reduce redness, photophobia, pain
Side effects; local irritation to the ocular surface/impaired healing
Rarely associated with keratitis and corneal melting
Steroids
More potent but potentially serious side effects
Increase intraocular pressure, accelerated cataract formation and potentiation of some infections
Anti-microbails often used concurrently
New “designer” steroids less likely to cause side effects
Endophthalmitis
Rare but serious interocular infection
Associated with recent surgery, injury or immunocompromised individuals
Specimens for culture often obtained in the operating room
Concurrent injection of intraocular antimicrobials
Often requires systemic therapy
Corneal ulcers require aggressive therapy
Specimens from corneal scraping for cultures/slides for staining
Topical therapy-broad spectrum/specially formulated fortified antibiotics
Compounding pharmacies
Around the clock treatment
Treatment or ocular infections due to bacteria, viruses, fungi or protozoans
More often used for prophylaxis (pre-operative, minor injuries)
Available as solutions, ointment, and as injectable forms
Various mechanisms of action and spectrums of activity
Cultures or slides for identification of the organism may guide therapy
Broad spectrum antibiotics (or combinations) typically institute prior to culture results
Treatment adjusted based on response/laboratory results
Miotics
Once the mainstay of topical glaucoma therapy, but are now used less frequently
Require frequent dosing and cause pupillary constrictions
Combination products
Simplify dosing regiment
Actions and side effects related to individual components
Anti-Allergy and Dry eye medications
Environmental allergies effect approximately 15% of the general population
Systemic medications often ineffective in treating ocular symptoms
Mild allergies
Artificial tears and cool compresses may suffice
Over the counter medications are available for ocular allergies, as well as prescription medications
Moderate to severe allergies
Prescription medications
Medications block inflammatory mediators involved in the allergic response
Steroids reserved for severe allergies unresponsive to other therapies
Newer steroids with improved safety now used for allergic eye disease.
Dry eyes
Artificial tears
Preserved or non-preserved
Puntual plugs
Anti-inflammatory medications
Immune modulating medicationsMainstay of glaucoma therapy
Various mechanisms of action
Alpha Agonists
Short term use to prevent increased pressure after laser treatment
Long-term use for the treatment of open-angle glaucoma
Side effects; fatigue and other CNS effects; often less bothersome with adaptation
Beta Blockers
Selective and non-selective formulations
Systemic side effects: slowing of the heart rate, hypotension and exacerbation of asthma
Selective beta blockers may decrease side effects
Carbonic Anhydrase Inhibitors (CAI)
Decrease aqueous production
Systemic or topical
Side effects: GI upset, tingling, and parenthesis and altered taste and smell
Metabolic disturbances and, rarely, bone marrow suppression
Topical use decrease side effects
Avoid in patients with sulfonamide allergies.
Prostagladins
Effective and convenient
Local hyperemia, itching, and stinging
Darkening of iris and increased peri-ocular pigmentation
Enhanced growth of the lashes
Avoid in patients with a history of iritis or herpetic eye infections.
