Opthalamic Drugs Flashcards
The topical route is used to target which structures of the eye? (4)
Conjunctiva
Cornea
Anterior Uvea
Eye Lids
Systemic route is used to target which structures of the eye? (4)
Eye Lids
Posterior Segment
Optic nerve
Anterior Segment
Which structures of the eye serve as drug reservoirs? (3)
Cornea
Lens
Uveal pigment (melanin)
Which drugs are formulated for topical administration?
Solutions, suspensions & ointments
Which route of admin allows for depot storage & achieves [high] in the ANTERIOR chamber?
Subconjunctival Therapy
Which route of admin achieves very high [drug] by injection of the drug into the AQUEOUS/VITREOUS HUMOR?
Intracameral Therapy
Absorption after TOPICAL admin is determined by what? (TQ)
Amt. of time drug hangs around Nasolacrimal drainage Binding to tear proteins Metabolism by tear & tissue proteins Diffusion across cornea & conjunctiva
Systemic distribution of TOPICALLY admin. drugs?
Nasal mucosal absorption
Local ocular distribution
How easily is passes the cornea & accumulates in the aqueous humor
Does is bind melanin?
Enzymatic biotransformation occurs in the eye via _________.
Esterases
Which type of drugs are more effective in the eye?
pro-drugs
What 2 agents cause MYDRIASIS (dilation) of the pupil?
Sympathomimetic drugs
Parasympatholytic drugs
What agent causes MIOSIS (constr.) of the pupil?
Parasympathomimetic drugs
What agents cause pinpoint pupils?
Opioids
What should you always do before using anti-biotics on the eyes? (TQ)
ID the pathogen!!
NEVER TX NON-INFECTED EYES (resistance)
What 3 anti-biotics are frequently used to TX eyes in Vet med?
Chloramphenicol
Fluoroquinolones (Cipro)
Gentamicin-Amikacin-Tobramycin combo
What drugs are your 1st choice for TXing corneal ulcers & bacterial conjunctivits?
BNP
NPG
Which anti-microbial is the 1st choice in small animal practice? What’s the problem?
Chloramphenicol
won’t TX Pseudomonas
Which anti-microbial will penetrate an intact cornea?
Ciprofloxacin
Which drugs do you use to TX keratomycosis?
Polyene antibiotics
Imidazoles
Nucleoside analogs
What 3 drugs do you use equal amts of to TX corneal ulcers?
Natamycin
Tobramycin
Cefazolin
What can you use to cause proteinase inhibition (thereby TXing corneal ulcers)?
Plasma alpha2-macroglobulin Chelating agents (EDTA, Acetylcysteine, & Tetracyclines)
How can you decrease intraocular pressure & TX glaucoma? (4)
Decr. aqueous humor production
Incr. aqueous humor outflow
Neuroprotection from glutamate signalling
Surgery?
What are 3 topical prostaglandin analogs used to TX glaucoma?
Latanoprost
Bimatoprost
Travoprost
What are 3 beta-adrenoceptor antagonists used to TX glaucoma?
Timolol
Metipranolol
Betaxolol
What drugs reduce formation of bicarbonate & reduce fluid transport (glaucoma TX)?
carbonic anhydrase inhibitors
What drug increases aqueous outflow via increasing trabecular outflow?
Pilocarpine (topical miotic)
What Ca channel blocker can be used to prevent excitotoxicty in glaucoma?
Amlodipine
What NMDA channel blocker can be used to prevent excitotoxicity in glaucoma?
Memantine
What type of drugs can be used to TX allergic conjunctivits? (TQ)
Antihistamines
Mast-cell stabilizers
What drugs can you NOT use on a damaged cornea? (TQ)
Glucocorticoids
What are the main anatagonists used in Vet med?
Muscarinic antagonists
What disinfectant can be used when DXing eye issues?
2% povidone iodine
What is the main route of entry & absorption pathway into the eye?
Corneal route
Cornea–> Aqueous humor–> Iris–> systemic circulation
How can you change the elimination half life of eye meds? (3)
change tear production
change drainage
change blinking rate
What 2 drugs are subconjunctival therapy used for?
Antibiotics
Corticosteriods
What are the 2 host-derived proteinases that lead to corneal ulceration?
zinc metalloproteinases (MMPs) Neutrophil serine proteinase
What are the systemic proteinase inhibitors used to TX corneal ulcres?
Homologous plasma or serum- topically
Combo w/ EDTA or Acetylcysteine
How does heparin inhibit proteinases? (TQ)
Impedes extravasation of leukocytes
Which types of proteinases do Ilomastat inhibit?
Inhibits endogenous & Pseudomonas proteinases
Which drug class affects trabecular outflow?
Muscarinic agonists
Which drug class affects uveoscleral outflow?
Prostaglandin agonists
Which drug classes affect aqueous humor inflow? (3)
Beta- blockers
Alpha 2 Agonists
Carbonic Anhydrase Inhibitors
What is the MOA of Beta-blockers?
(Timolol, Metipranolo, & Betaxolol)
non-selective drugs
blocks cAMP-PKA pathways and reduces aqueous humor production
What receptor do prostaglandin analogs bind to?
Gq receptor - Phospholipase C- IP3-Ca pathway
What is the MOA of Alpha 2 Agonists? (TQ)
Inhibits adenylate cyclase
reduced Na/K/ATPase activity
What is the MOA of carbonic anhydrase inhibitors?
reduce formation of bicarbonate & fluid transport
Which anti-inflammatory is immunosuppressive & highly lipophilic? (TQ)
Cyclosporin A
What drug is sympatholytic & causes miosis?
Timolol acetate
What 3 drugs are parasympatholytic & cause mydriasis?
Atropine
Tropicamide
Scopolamine
Which 2 drugs are sympthomimetic drugs & cause mydriasis? (used to TX anterior uveitis)
Phenylephrine
Epinephrine
What local anaesthetics can be used as DX aids?
Proparacaine & Tetracaine –> topical
Lidocaine & Bupivacaine –> infiltration anaesthetics
