Ocular Pharm: L2: Ocular Routes of Drug Administration Flashcards Preview

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Flashcards in Ocular Pharm: L2: Ocular Routes of Drug Administration Deck (31)
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1
Q

Barriers to Drug Absorption

  1. What are 2 barriers from the outside?
  2. 2 barriers from the Circulatory System?
A
  1. a. Tight junctions b/w Corneal Epi Cells
    b. Globe is pretty impermeable
  2. a. Blood-Aq. Barrier in CB
    b. Blood-Retinal Barrier in RPE/Choroid
2
Q

5 Routes of Administration we talked about? (TIPPI)

A
  1. Topical
  2. Intracameral
  3. Periocular
  4. Photodynamic
  5. Intravitreal
3
Q

What type of Route of administration encompasses most of the drugs we will use?

A
  1. Topical Solutions: in a bottle w/Eyedropper top.
4
Q

Bottle Cap Colors

  1. Tan
  2. Pink
  3. Gray
  4. Red
  5. Green
  6. Blue and Yellow
  7. Purple
  8. Orange
  9. Turquoise
A
  1. Antibiotic
  2. Steroid
  3. NSAID
  4. Mydriatic and Cycloplegic
  5. Miotic
  6. Beta Blockers (Blue = Lower dosage)
  7. Adrenergic Agonists
  8. Carbonic Anhydrase Inhibitors
  9. Prostaglandin Analogs
5
Q

Topical: Solutions (2)

  1. Advantages: 4
A
  1. Easy to use; Convenient; Pt can self-administer; Delivers drug primarily to the eye.
6
Q

Topical: Solutions (2)

  1. Disadvantages (3)
A
  1. Limited globe penetration (good for eye surface and adnexia); Some drugs can make it to the Ant Segment
  2. Not good for Post. Segment
  3. Tip can be contaminated by contact
7
Q

Topical: Solutions (3)

  1. Is most of the drop retained in the tear fluid? Why or why not?
  2. How do you properly instill so you get better effects?
  3. How much of a drop is needed if using it QID, OU, for 1 week?
    a. How much would be given in an Rx for this?
    b. Rx is Less for what medications?
    c. 1
A
  1. No. Cuz 1 drop = 50-70 ul; and Normal Tear Volume = 3-11 ul
  2. Apply to lower Fornix; Have pt Close eyes; Or have them apply pressure over Nasal Puncta
  3. 3-4 ml
    a. 5 ml to allow for missed instillations
    b. for Anti-glaucoma meds (smaller drop volume): (2.5 ml/wk QID, OU)
    * 4-3-2-1…not sure what he’s going for here.
8
Q

Topical: Solutions (4)

  1. Big thing to warn to patients?
    a. How do you instill them in children?
A
  1. They HURT (“Tingle”): Warn pts; and Children will NOT LIKE THEM.
    a. Instill in Nasal Canthus w/Eyes Closed
  • remember, it’s hard to hit the eye w/a drop…might need to train pts over 75 and with arthritis.
  • They have commercial devices to help with this.
9
Q

Topical: Solutions (5)

  1. Some drops are available in unit dose dispensers (usually ATs, Restasis…some drugs)
    a. Problem with them?
    b. good for pts w/what issue?
A
  1. a. Preservative-free so you have to dispose of them 1 day after opening.
    b. who are sensitive to preservatives. For dosing more often than QID
10
Q

Topical Solutions: Compliance

  1. Cassard et. al, 2012 study: Observed 70 glaucoma pts who had been self-administering Anti-glaucoma drops for at least 6 months.
    a. % that actually instilled them correctly?
    b. % that missed their eyes?
    c. % that touched tip to eyelid or Periocular tissue
    d. For this reason, what is important?
A
  1. a. 8.6%
    b. 31% (this was a big highlighted thing in his slide)
    c. 75%
    d. Pt education should include practicing instilling drops while in office; proficiency should be checked at F/U visits
11
Q

Topical: Suspensions

  1. Drug is in suspension in container, and what happens to it after instillation of a drop?
  2. What must be done BEFORE use?
  3. Commonly used for drugs with what solubility type?
    a. Example?
  4. What can suspension do to the Dropper tip?
  5. What should you ALWAYS use for ANTERIOR UVEITIS (what drug…not generic version)
A
  1. it Dissolves
  2. Have to Shake the Container
  3. with Low Aqueous Solubility
    a. Steroids
  4. it can clog it.
  5. PredForte
12
Q

Topical: Sprays

  1. Most common use is for administering what to children?
    a. What other reason?
  2. 2 Advantages
  3. 2 Disadvantages
A
  1. Mydriatics and Cycloplegics
    a. Also for some ATs
  2. a. can spray drug on closed eyelid
    b. Can be less irritating and frightening
  3. a. Limited variety of drugs in this form unless you have them specially formulated
    b. children still don’t like it.
13
Q

Topical: Ointments (1)

  1. Main use is to deliver what kind of drug?
  2. Supplied in what?
  3. Dosage is specified as what?
  4. Applied to what area of the eye?
  5. Can also be applied to where?
    a. Advantage of doing this?
A
  1. Antibiotics
  2. in a small tube
  3. length of ointment squeezed from the tube
  4. Lower Canthus
  5. Upper lid margins and canthi w/cotton application
    a. less burning and irriation
14
Q

Topical: Ointments (2)

  1. Advantages
    a. Delivers drug to the eye over what period of time?

b. What else? (4)
2. Disadvantages (4)

A
  1. a. over a longer period of time: ribbon of ointment acts as a resevoir
    b. Less frequent dosing needed and it’s less scary for children
    c. Good for pts in Prone position (macular hole repair) or who struggle w/drops
    d. Vehicle itself can be soothing
  2. a. smaller variety of drugs available
    b. ointment can become entrapped in wound, if present, and impair healing
    c. blurs vision for a time
    d. can cause contact dermatitis
15
Q

Topical: Gels

  1. How is it administered?
  2. Primary use (for what disease meds?)
  3. Advantages (2)
  4. Disadvantages?
A
  1. Drug w/in gel and gets released as gel dissolves
  2. Anti-glaucoma meds and ATs
  3. Like ointments; Cause less blurring than ointments
  4. Also similar to those for ointments
16
Q

Topical: Solid Delivery Systems (1)

  1. SCL is IMPREGNATED with what?
    a. Purpose?
    b. Duration (what order of kinetics)?
  2. Collagen Shields
    a. Continuous release for how many hours?
  3. Inserts
    a. Used to Treat what disease?

b. Device is placed where in the eye?
c. What’s the Active Ingredient?

A
  1. with the drug
    a. More uniform rate of drug delivery
    b. Short Duration (1st Order Kinetics)
  2. a. up to 72 hrs as shield dissolves (thermodynamic rather than kinetic process)
  3. a. moderate to Severe Dry Eye
    b. in the lower fornix
    c. The Dissolving insert. Problem: Can blur image more than gels.
17
Q

Topical: Solid Delivery Systems (2)

  1. Filter Paper Strips
    a. Ex
    b. Why are these good?
    c. Eliminates risk of what?
  2. Cotton Pledgets
    a. Why are they good?
    b. Usually used with what 2 drug types?
A
  1. a. Fluorescein Dye
    b. Easy delivery of Pre-measured dose
    c. of contamination
  2. a. Prolongs Ocular Contact time w/solutions that are normally instilled DIRECTLY into the eye
    b. Mydriatics or Anesthetics
18
Q

Topical: Continuous Flow Devices

  1. Conventional Irrigation
    a. Used mainly for what 2 things?
  2. Continuous Irrigation Systems
    a. Morgan Lens: Large CL with opening in what?
A
  1. a. for Chemical burns or foreign bodies

2. a. in CENTER Attached to Tubing (never seen anyone really do this…but could be used)

19
Q

Topical: Lid Scrubs

  1. Used for treating what?
  2. What is applied to the Cotton-tipped applicator
A
  1. Blepharitis
  2. Antibiotic or Cleaning Agent (like baby shampoo)
    * Prepackaged kits available
20
Q

Periocular: What five injections are there?

A
  1. Lesion
  2. Subconjunctival
  3. Sub-Tenon’s
  4. Retrobulbar
  5. Peribulbar
21
Q

Periocular: Lesional

  1. Injected into or thru what?
  2. Similar to what other injection?
  3. Injection on what SIDE of the LESION allows for LARGER INJECTION VOLUME?
A
  1. Lesion (like a chalazion)
  2. Subcutaneous Injection
  3. the DISTAL SIDE
22
Q

Periocular: Subconjunctival (1)

  1. Injection of Drug into space b/w Anterior Conjunctiva and what?
  2. Needle can pass thru what?
  3. Usually used to TREAT severe what? (3)
  4. Also used after what procedure(s)
A
  1. and Tenon’s Capsule
  2. Conjunctiva or Lower Lid
  3. a. Severe Corneal Disease
    b. Anterior Uveitis
    c. Scleritis
  4. Trabeculectomy (for 5FU administration) or to administer Anesthetic for Eye Surgery
23
Q

Periocular: Subconjunctival (2)

  1. Advantages
    a. What is achieved at the site of need w/limited Systemic Exposure?

b. Better availability of drugs that Poorly do what?
c. Can inject drugs at time of what?
d. Useful in patients who are not reliable to use what?

  1. Disadvantages
    a. Has to be what?
    b. Injection site is Outside of Tenon’s Capsule, which reduces what?
A
  1. a. High Concentration
    b. poorly penetrate the Corneal epithelium
    c. of Surgery; Decreases need for eye drops
    d. to use Topical Drugs
  2. a. injected
    b. reduces absorption into the globe
24
Q

Periocular: Sub-Tenon’s

  1. Used for what?
  2. Drug doesn’t have to penetrate what to reach the INTERIOR of the GLOBE?
A
  1. Severe Corneal Disease (graft rejection), severe Ant Uveitis, Mid-zone post Uveitis, macular inflammation and Edema
  2. Tenon’s Capsule
25
Q

Periocular: Sub-Tenon’s (2)

  1. Advantages
  2. Disadvantages
A
  1. a. High concentration at site w/limited systemic Exposure
    b. Better drug penetration
    c. better drug availability than subconjunctival injection
    d. Inject drugs at time of surgery (decreases need for eye drops)
  2. has to be injected. High risk of puncturing glove or injuring visual structures
26
Q

Periocular: Retrobular

  1. Mainly used to administer what?
  2. Also used for what injection types?
  3. Can administer what 2 things for Intractable pain in a blind eye?
  4. Significant risk of injuring what?
A
  1. Anesthetics for Intraocular surgery
  2. Corticosteroid Injections (controversial)
  3. Alcohol or Phenol
  4. globe or other ocular structures
27
Q

Periocular: Peribulbar

  1. Main use?
  2. Injection given into space outside of what structures?
  3. Drug passes thru Fascia of what, to what?
  4. Less chance of damaging globe or other ocular structures than what other procedure?
A
  1. Anesthetic administration
  2. of EOMs
  3. of EOMs, to the globe
  4. than Retrobulbar injections
28
Q

Intracameral

  1. Definition:
  2. Injection of drug into what of the eye?
  3. Often used with what surgery?
    a. To administer what?
  4. Does it increase the risk over the surgery itself?
A
  1. w/in a Chamber
  2. Anterior Chamber of the Eye
  3. Cataract Surgery
    a. Viscoelastic substances or drugs (anesthetics or corticosteroids)
  4. No
29
Q

Intravitreal (1): We can’t do this one yet

  1. Drug injected into what?
  2. Main uses?
  3. Advantage?
  4. Disadvantage?
A
  1. Vitreous
  2. Antibiotic Tx; Corticosteroids to treat CSME in diabetes; VEGF Inhibitors for Wet AMD and Diabetes
  3. high dose that may not cross BBB
  4. Can get infection from penetrating globe (endophthalmitis)
30
Q

Periocular: Intravitreal (2)

  1. Inserts also used to deliver drugs intravitreally
    a. Retisert: what is it?
    b. Vitrasert: What is it?
    c. Advantage?
    d. Disadvantage?
A
  1. a. Steroid
    b. Antiviral
    c. Sustained drug delivery, fewer injection
    d. hard to stop drug deliver if there are adverse effects
31
Q

Photodynamic Therapy (seldom used, unless person doesn’t respond to anti-VEGF)

  1. Main use?
  2. What is the photoactive agent?
    a. How does it get into the body?
  3. Light at what nm (non-thermal) is directed at what?
  4. Activation of Verteporfin generates what?
    a. This preferentially occludes what?
A
  1. Treat “wet” AMD
  2. Verteporfin
    a. IV
  3. 689 nm; At the lesion in the eye
  4. free radicals
    a. Abnormal vessels