Ocular Pharmacology pt 2

Question 1

when do we use bactericidal drugs in ophtho?

Answer 1

• Bactericidal antibiotics are reserved for corneal ulceration, severe infections or for moderate infections in patients with a compromised immune system (i.e. diabetes mellitus)

Question 2

use of topical antibiotics and frequency of admin?

Answer 2

• commonly used to treat conjunctival and corneal infectious diseases
• Topical antibiotics should be instilled a minimum of 4 times daily
• every 2-4 hours in severe infections

Question 3

Bactericidal antibiotics include:

Answer 3

• aminoglycosides and fluoroquinolones

Question 4

tobramycin property vs other bactericidal antibiotics

Answer 4

tobramycin is less epitheliotoxic

Question 5

issue with fluoroquinolones

Answer 5

inhibit keratocyte proliferation and produce cytotoxicity
- can potentially cause a deep corneal ulcer to progress to a descemetocele

Question 6

how to use topical cephalosporins?

Answer 6

• cephazolin can be easily compounded in practice with artificial tears
• good counterpart to aminoglycosides or fluoroquinolones in cases of serious
  corneal infections where bacterial sensitivity is not yet available

Question 7

Subconjunctival antibiotics duration of action

Answer 7

• duration of action can be short

Question 8

systemic antibiotic linked with acute blindness in cats

Answer 8

Enrofloxacin

Question 9

first line choice for bacterial blepharitis and orbital abscess/cellulitis

Answer 9

Amoxicillin-clavulanic acid combination antibiotics

Question 10

when do we generally use antivirals in ophtho?

Answer 10

• usually reserved for severe primary feline herpesvirus infections that include corneal
  ulcers and potential for symblepharon development

Question 11

antiviral of choice for treating severe, chronic, or stromal feline herpesvirus keratitis

Answer 11

Famciclovir, systemic antiviral

Question 12

L-lysine use for feline herpes

Answer 12

• adjunct therapy of feline herpesvirus infections, oral supplement
• shown to decrease the severity of clinical signs in primary infections and reduce viral shedding in latent infections

Question 13

Topical antifungal therapy for equine ulcerative keratitis and stromal abscess suspected to have a fungal infection, options

Answer 13

• Voriconazole 1% and fluconazole intravenous solutions have demonstrated good corneal penetration
• Itraconazole 1% combined with 30% DMSO can be compounded as an ointment with great corneal penetration

Question 14

use of corticosteroids for eyes

Answer 14

• By minimizing inflammation, scarring is reduced, transparency can be maintained and damage to uveal and retinal tissues can be diminished

Question 15

Topical corticosteroids are mainly prescribed for:

Answer 15

• chronic superficial keratitis
• atopic conjunctivitis
• idiopathic or immune-mediated uveitis

Question 16

Systemic corticosteroids are commonly prescribed for

Answer 16

• retinal detachment due to immune-mediated causes
• inflammatory conditions of the orbit, sclera, uvea, retina and optic nerve

Question 17

when are corticosteroids contraindicated?
other drawbacks?

Answer 17

Topical and systemic corticosteroids are contraindicated with diabetic patients
and corneal ulcerations
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- Topical corticosteroids can promote corneal deposition of calcium and lipid with chronic use.
- Topical corticosteroids can also induce iatrogenic Cushing’s syndrome and adrenal gland suppression.
- Lastly, topical corticosteroids will increase blood glucose and steroid-induced alkaline phosphatase.

Question 18

when are subconjunctival corticosteroids used?

Answer 18

The main advantage of these injections is
the reduction of topical administration of steroids in difficult patients

Question 19

when are topical NSAIDs used?

Answer 19

• pre-operatively in cataract surgery
• non-ulcerative keratitis (pigmentary or vascular)
• uveitis

Question 20

when are topical NSAIDs contraindicated?

Answer 20

corneal ulceration, glaucoma, and coagulopathies