pharmacology Flashcards
is the epithelium + stroma lipid or water soluble? what does this mean for drugs administrated via cornea?
epithelium = lipophilic + hydrophobic - lipid soluble drugs penetrate
stroma = lipophobic + hydrophilic - water soluble drugs penetrate stroma
must have lipophilic + hydrophilic properties eg chloramphenicol
how to enhance corneal penetration of topical drugs?
more hydrophobic = alcohol or acetate
(prednisolone acetate used post-operatively)
more hydrophilic = phosphate
prednisolone phosphate for cornea disease/low dose steroids)
benzalkonium - disrupts lipid layer of tear film
most common topical antibiotic
chloramphenicol
what antibiotic is given in patient with corneal ulcer?
ofloxacin
action + use of topical steroids
suppress inflammation
used topically in -
post op cataracts
uveitis
to prevent corneal graft rejection
local eye side effects of steroids
cataract
glaucoma
exacerbation of viral infection
strength ladder of topical steroids
FML
prednisolone phosphate
betamethasone
dexamethasone/prednisolone acetate
MoA of local anaesthetic
blocks sodium channels + impedes nerve conduction
mydriatics
causes pupil dilation by blocking parasympathetic supply to iris
cause cycloplegia = stop lens from focusing
examples = tropicamide, cyclopentlate
give example of drug that constricts + dilates pupil
constricts = pilocarpine
dilates = atropine
drug group that can cause maculopathy
chloroquine
drug that can cause optic neuropathy
ethambutol - TB treatment
when might you use intravitreal as a method of drug admin?
antibiotics in endophthalmitis
MoA of chloramphenicol
inhibits peptidyl transferase enzyme - stops bacterial protein eing made
bactericidal for strep + haempphilus
bacteriostatic (stops growth) for strep
