Flashcards in Ocular Pharmacology Deck (89):
What is uveitis?
Inflammation of the uvea, iris, and ciliary body
Is the epithelium of the cornea hydrophobic or hydrophilic?
Is the endothelium of the cornea hydrophobic or hydrophilic?
Is the stroma of the cornea hydrophobic or hydrophilic?
Would an oil-based medication more easily penetrate the corneal epithelium or stroma?
Would a water-based medication more easily penetrate the corneal endothelium or stroma?
When suspicious of a corneal ulcer, you would use a fluorescing stain toe identify the ulcer. Which layer of the cornea does this stain adhere to?
What are the 2 possible ways of drug absorption when topically administered?
1. Penetration of the cornea
2. Systemic absorption through the conjunctiva and the nasolacrimal system
Higher drug ____ or higher ____ of treatment can be used in order to increase the drug concentration in a treated tissue?
Higher drug CONCENTRATION or higher FREQUENCY of treatment can be used in order to increase the drug concentration in a treated tissue.
Wait at least ___ minutes between different eye drops.
Which MUST be shook well prior to application, an ophthalmic solution or suspension?
Which is more stable, ophthalmic drops or ointment?
Explain the penetration of subconjunctival injections.
Bypass the conjunctival and corneal barriers for direct scleral absorption
What are the indications for subconjunctival injection?
1. Bolus of medication for animals not permitting repeated topical application (Ex: wildlife, aggressive animal)
2. For water-soluble drugs that would penetrate the cornea poorly
3. For long-acting drugs
4. To confine a drug's effect to the eye
Again, what are the indications for subconjunctival injections?
1. For long-acting drugs
2. For water-soluble drugs (unable to penetrate the cornea)
3. To confine a drug's effect to the eye
4. For animals that will not permit repeated topical administration
True or False: Systemically administered drugs have no effect on the anterior or vitreous chambers of the eye.
FALSE - systemic drugs do have an effect on these chambers.
True or Falase: Most antibiotics penetrate the cornea well.
FALSE - most antibiotics have poor corneal penetration.
Name the 3 polypeptide ocular drugs.
1. Polymyxin B
Are the polypeptides bacteriostatic or bactericidal?
Describe the spectrum of the polypeptides.
True or False: The polypeptides can be administered topically, subconjunctivally, or systemically.
FALSE - the polypeptides are toxic when administered subconjunctivally or systemically. The polypeptides should only be used topically.
Name 3 aminoglycosides used in ocular pharmacology.
Describe the spectrum of the aminoglycosides.
Are the aminoglycosides bactericidal or bacteriostatic?
True or False: These aminoglycosides can be used systemically.
FALSE - aminoglycosides are toxic when used systemically.
Which of the following is the most effective aminoglycoside, tobramycin or gentamicin?
Which of the following is least epitheliotoxic, tobramycin or gentamicin?
What is the most commonly used quinolone in ocular pharmacology?
Describe the spectrum of the quinolones.
Broad spectrum (limited against anaerobes)
Which antibiotic is effective against resistant staphylococcus?
The cephalosporin cefazolin is used mainly for what type of ocular infections?
Staph and strep infections
True or False: The cephalosporin cefazolin easily penetrates the cornea.
FALSE - cefazolin has LOW corneal permeability.
Which of the following are the tetracyclines, antibacterial, anti-inflammatory, anti-protozoal, anti-protease.
Are the tetras bacteriostatic or bactericidal?
The tetras are effective against ____ and ____.
2. Chlamydophila (mainly in kittens)
What is the only ophthalmic preparation of tetracycline?
Which fungal organism is miconazole effective against?
True or False: Miconazole has poor penetration of the cornea.
Which 2 fungal species is voriconazole effective against?
True or False: Voriconazole has good penetration of the cornea.
What type of antivirals are currently the main antivirals used in veterinary ophthalmology?
Nucleoside analogs are most frequently used to treat which virus?
Nucleoside analogs are virostatic or virocidal?
What is the administration protocol for Idoxuridine?
Every 2 hours for 2 days then 4-6 x/day for 3-4 weeks
Which of the following is not effective against feline herpesvirus: Nucleoside analogs, Cidofovir, Acyclovir.
Which dose of Famciclovir has been reported to have a positive clinical effect?
90 mg/kg every 12 hours
How does L-lysine interfere with viral replication?
Ties up arginine so it is not available for viral replication
What can you use as a life-long food additive for chronic recurring feline herpesvirus infections?
What is the administration protocol of L-lysine in PREVENTION of feline herpesvirus?
250-500 mg/cat every 24 hours
What is the administration protocol of L-lysine in TREATMENT of feline herpesvirus?
250-500 mg/cat every 12 hours
Do NOT use topical steroids on an eye with what?
Corticosteroids decrease the release of ____ from injured cell membranes.
Corticosteroids block degranulation of what 3 cell types?
2. Mast cells
3. Basal cells
Corticosteroids prevent release of histamine, ____, and ____.
Corticosteroids increase or decrease capillary permeability?
Corticosteroids increase or decrease vasodilation?
Corticosteroids increase or decrease neovascularization?
What are the 3 general indications for corticosteroid use?
3. Immune-mediated diseases
How do corticosteroids affect fibroblast responses?
Inhibit fibroblast responses
How do corticosteroids affect epithelial regeneration?
Interfere with epithelial regeneration
How do corticosteroids affect collagen?
They potentiate proteinases that break down collagen
What affect do corticosteroids have on intraocular pressure?
Increase intraocular pressure
What affect do corticosteroids have on corneal epithelium and stroma?
Cause degeneration with long term use
True or False: Just like in the human being, corticosteroids cause cataracts in animals.
FALSE - corticosteroids do NOT cause cataracts in animals.
True of False: Corticosteroid can facilitate viral infections in prolonged use.
FALSE - corticosteroids can facilitate FUNGAL infections in prolonged use.
Corticosteroids should be avoiding with metabolic diseases, especially ____ in small animals.
Which of the following topical corticosteroids has the best corneal penetration: acetate, alcohol, or phosphate?
What would you use for intraocular inflammation?
What would you use for extraocular inflammation?
Dexamethasone sodium phosphate
Which corticosteroid is systemically used in small animals?
Prednisone or prednisolone
Which corticosteroid is systemically used in horses?
Which is preferred in exotic animals, steroids or NSAIDs?
How do NSAIDs work?
Prevent the formation of prostaglandins from arachidonic acid
What are the primary mediators of ocular inflammation?
What NSAID can be used in horses to treat SCC?
What are the 2 most common treatments for KCS to date?
2. Cyclosporin (Optimmune)
What affect do Tacrolimus and Cyclosporin have on tear production?
Stimulate tear production
What are serum, N-acetylcysteine, EDTA, and tetracyclines?
How do carbonic anhydrase inhibitors work?
Block the carbonic anhydrase enzyme, decreasing aqueous humor production
For what condition would you use carbonic anhydrase inhibitors?
How do prostaglandin anaglogs decrease intraocular pressure?
By increasing uveoscleral outflow
What are Latanoprost and Travoprost?
Which of the following is most cost effective, Latanoprost or Travoprost?
How are beta-adrenergic blockers anti-glaucoma?
Decrease aqueous humor production
They do this by blocking beta receptors on the ciliary epithelium
What is the adverse effect of using a beta blocker?
True or False: Beta blockers can be used alone in the treatment of glaucoma.
FALSE - Beta blockers are not adequate in treating glaucoma when used alone. They are preferably used in combination with a carbonic anhydrase inhibitor.
Osmotic diuresis can be used to lower intraocular pressure. What is the mechanism of this?
Shrinks the vitreous of the eye
What is an example of a drug that can cause osmotic diuresis and shrinkage of the vitreous by association?