Clinical Administration Of Ocular Therapeutic Medications Flashcards
Agonist
Acts directly on receptor
Antagonist
Binds to receptor and inhibits agonist
Normal tear film volume, including fluid trapped in conjunctival folds
8-10 uL
Tear film volume that can be held after given a drop if lids are not squeezed and cul-de-sac is utilized
30 uL
Typical ophthalmic drop volume
50 uL
Three different fates of excess drop fluid
Drain through nasolacrimal duct
Absorbed through nasal mucosa or swallowed
Rolls to cheek
20 drops =
= 1mL
Techniques to Maximize Effect of Each Drop
Fraunfelder pouch
Looking down
Punctal occlusion
Hurdles in drop administration (dilution)
Tears
Aqueous humor -> trabecular meshwork
Corneal epithelium penetration
Lipophilic drugs
Resists hydrophilic drugs
Fluorescein is a __________ drug.
Hydrophilic
Corneal stroma penetration
Hydrophilic drugs
Resists lipophilic drugs
To penetrate the cornea, there needs to be:
A balance of hydrophilic and lipophilic properties
Pro-drug
Inactive compound is activated in thebody to active compound
(biotransformation)
Getting the maximum effect from each drop equals the maximum therapeutic effect.
FALSE
Ways to get max therapeutic effect
-increased drug concentration
~higher concentration; fortified Abx
- more frequent dose
- loading dose
-residence time
~thicker drop; punctual occlusion
The increased dose frequency is typically
QID
Corneal ulcer treatment
Ciloxan ophth soln q15min
What is punctual plug material?
Collagen
For children, where is the drop instilled in closed eyes?
Nasal canthus
Green
Miotic
Red
Mydriatic/ cycloplegic
Brown
Antibiotic
Grey
NSAID
Yellow
0.5% beta blocker
Blue
0.25% beta blocker
Purple
Alpha agonist
Teal/clear
Prostaglandin analogue
Orange
CAI
Characteristics of a solution
- solid in a liquid
- always transparent
- small particles
- fully dissolve
- homogenous
- permanent, does not settle out
- NO SHAKING
- Tobramycin
Characteristics of a suspension
- solid in a liquid
- cloudy mixture of two or more substances that settle in standing
- large particles
- do not dissolve
- temporary
- SHAKE
- Prednisolone acetate
Characteristics of a colloid
- liquid in a liquid
- hybrid between a solution and a suspension
- will not separate out
- NO SHAKING
- Durezol
Where are ophthalmic ointments applied?
Inferior lid; lid margin
The therapeutic level reached by an ointment is the same as that reached by a drop.
False. It’s less.
Ointment disadvantages
Blurred vision for 5 minutes
Same therapeutic levels as drops not reached
Limited number of concentrations available
Use in tx with ophth soln
Contact dermatitis
Don’t use ointments when:
- full thickness corneal laceration
- with some topical meds
- some corneal ulcers
Ophthalmic gels
Ointment/ drop hybrid
Which type of ophthalmic agent has a timed-release effect?
Gels
When are ophth gels usually applied?
QHS
Types of lid scrubs
Detergents
Prepared pads and solutions
Antibiotic ointment
Treatment of MGD
Heat and hot soaks
Anti inflammatory tx
- doxy
- omega 3
What is Ocusert?
A Pilocarpine-soaked chunk between 2 polymer membranes
-replaced every 7 days
How does Lacrisert work?
It’s a slow-release artificial tear that is applied to the inferior sac and melts throughout the day
What is a Morgan lens?
A continuous irrigation system from a saline bag that flushes out eye quickly
Mechanism of action
How a drug interacts with a receptor in the bodyto moderate the rate at which an action takes place.
What is the most common injection?
Subconjunctival
Conditions that may require subconj injections
Severe keratitis
Corneal ulcer
Bacterial endophthalmitis
Conditions that require an anterior sub-Tenon’s injection
Pars planitis
Intermediate uveitis
Conditions that require a retrobulbar injection
Application of: anesthetics, corticosteroids, alcohol
Possible contraindication of adrenergic drugs
Cardiovascular drugs
Things to consider when prescribing meds to diabetic patients
Slow detox -> linger drug activity
Corticosteroid-induced hyperglycemia
Difficulty in dilation
Stevens-Johnson disease associated with
Sulfacetamides
Pediatric cycloplegic spray contents
- 3.75 ml of 2.0% Cyclopentolate
- 3.75 ml of 10% Phenylephrine
- 7.5 ml of 1.0% Tropicamide
Pediatric cycloplegic spray yields
15 mL of:
- 0.5% Cyclopentolate
- 2.5% Phenylephrine
- 0.5% Tropicamide
One spray of pediatric cycloplegic spray =
= 105uL or 2 drops
