Ophthalmic medications Flashcards
Advantages of ointments
Long contact time
Not diluted via tear film
Softens ocular discharge and crust
Helps prevent symblepharon
Less expensive
Disadvantages of ointments
Interferes with corneal epithelial lining
Add to discharge
Contact dermatitis
Dosing not precise
Difficult to sterilize and apply
Advantages of suspension (drops)
Less disturbance of vision, incident for contact derm, and less toxic to interior of eye
Easier application
Disadvantages of suspension (drops)
Short contact time, dilutes with tears, more expensive, shaking required, greater potential for systemic absorption
Antimicrobials
Triple antibiotic
Chloramphenicol
Tetracyclines
Erythromycin
Gentamicin/ Tobramycin
Ofloxacin/ ciprofloxacin/ moxifloxacin
Cefazolin
MOA for most antimicrobials
Inhibits bacterial protein synthesis by binding to 30S ribosomal subunits
Which antimicrobials are Mycoplasma and Chlamydophils sensitive to?
Tetracyclines, Erythromycin, Ofloxacin/ ciprofloxacin/ moxifloxacin
Triple antibiotic
Neopoly and Polymyxin B = gram -
Bacitracin and Gramicidin=gram +
Chloramphenicol uses
Deep and infected/melting corneal ulcerations or intraocular infections
Penetrates intact cornea
_______________ is resistant to Chloramphenicol and tetracyclines
Pseudomona aeuginosa
Tetracyclines
Bacteriostatic
Erythromycin
Targets gram +
Penetrates cornea
Use: Conjunctivitis
Gentamicin/ tobramycin
Targets gram -
Bactericidal
Poor intraocular penetration
Use: Ciliary body ablations (CBA)
Ofloxacin/ ciprofloxacin/ moxifloxacin
MOA: Inhibits DNA gyrase and prevents viral DNA synthesis
Bactericidal
Use: complicated corneal ulcers
Cefazolin
MOA: Destroys cell wall of bacteria
Bactericidal
Mix with sterile saline artificial tears (topical) or use intra operatively (IV)
Gram _________ are resistant to cefazolin
Negative
Anti-fungal administration
Topical, systemic, intranasal, IV
Antifungal marked for ophthalmic prep
Natamycin- attacks filamentous fungi and yeast
Azoles (anti-fungal)
MOA: destroys cell wall by inhibiting cytochrome P450
drugs ending is azole- micaonazole, voriconazole, etc
Silver sulfadiazine
Broad spectrum anti-fungal + Antiviral
Antivirals
Idoxuridine
Cidofovir
Trifluridine
Adenine Arabinoside
Idoxuridine
MOA: competes with thrymidine for incorporation of viral DNA
Virostatic, admin. 4-8 x a day
Cidofovir
MOA: inhibits viral replication by inhibiting viral DNA synthesis
Administer 2x a day, expensive
Anti-inflammatories MOA
Glucocorticoids blocks both cyclooxygenase and lipopoxygenase pathways
NSAIDs block the cyclic endoperoxidases (PGs)
compounded for ophthalmic use
Uses for anti-inflammatories
Preserve corneal transparency
Extra-ocular inflamm. diseases (keratitism conjunctivitis)
Uveitis
Reduced leukocyte accumulation
Adverse effects of anti-inflammatories
↓ corneal epithelial healing time, keratocyte proliferation and collagen, neovascularization, capillary permeability, vasodilation
Activates collagenase (digests cornea)
Interferes with host defenses
Corneal opacities
Steroids
Interferes with inflamm. mediators like arachidonic acid
Neopolydex (extraocular disease), dexamethasone SP, prednisolone aceate (corneal penetration)
NSAIDs
Inhibits synthesis of enzymes (cyclco-oxygenase, endoperoxide isomerase, PGs)
Ketorolac, diclofenas, flurbiporfen
Anti-glaucoma medications
Block aqueous humor pathway
Carbonic anhydrase inhibitors, beta blockers, latanoprost/ bematoprost/ travprost, demecarium bromide, pilocarpine
Carbonic anhydrase inhibitors
Dorzolamide
Causes irritation and mild blepharitis
Combined with timolol
Beta blockers
Timolol: nonselective, caution in animals with cardiac disease of asthma, prevents glaucoma
Betaxolol: Selective
Latanoprost/ bematoprost/ travprost
MOA: PG analog and miotic
Emergency glaucoma, trans-corneal reduction procedure for lens luxations
Effects of latanoprost/ bematoprost/ travprost
Causes miosis and prevents lens from entereing the anterior chamber (don’t use if already in chamber)
Demecarium bromide
Parasympathomimetic
Inhibits AChE and pseudocholinesterase
Indirectly causes miosis due to constriction of iris sphincter muscles, aiding in outflow of humor
Pilocarpine MOA
MOA: cholinergic muscanaric receptor agonist→ contracts ciliary body, ↑ outflow of humor and stimulates tear gland directly if nerve damage
Pilocarpine use
Neurogenic keratoconjunctivitis sicca
Adverse: hypersalivation, urinating, V/D
Orally or topically
Tear stimulators
Cyclosporine
Tacrolimus
Artificial tears and lubrications (I-drop vet gel, optixcare, AnHyPro, GenTeal)
Cyclosporine and Tacrolimus MOA
Reduces inflamm. associated with tear production, suppresses T cell function
Calcineurin inhibitor
Immunosuppressive
Cyclosporine and tacrolimus uses
KCS, pannus, immune mediated keratitis and excessive vasculature pigment
Mydratics
Atropine
Tropicamide
Epinephrine and phenylephrine
Atropine
ACh muscarinic receptor blocker, relaxes iris and ciliary body sphincter muscles
Therapeutic drops for pain
Wash hands after use
Beware of using atropine in what animals?
Horses and cats
Tropicamide
Same MOA as atropine
Dilates for OFA exams, ERGs, pre-op cataract surgery
Epinephrine and phenylephrine
Sympathomimetic
Causes vasoconstriction of vasculature and reduces bleeding during procedures
Anticollangenases
Serum (a2 macoglobulin)
EDTA (binds to Ca)
Amonion drops
Doxycycline
N-acetylcysteine
Amonion drops
Promotes cell migration and epithelialization
Medical management for desmetocele
Lubrication and anti-inflamm properties
Atracarium
Neuromuscular paralytic
Aids in cataract surgery so eye doesn’t move while extracting lens fibers
NaCl ointment or suspension (Muro)
Hyperosmotic solution that draws fluid from the cornea (corneal edema)
Endothelial degeneration
Tissue Plasminogen Activator (TPA)
Dissolves fibrin in aqueous humor
Reduces synechia, glaucoma, or cataract formation
Post-op to control inflammation