Pharmacology

Question 1

routes of administration for the eye

Answer 1

topical
subconjunctival
subtenosis (under conjunctiva)
ocular injections e.g. intravitreal and intracameral (anterior chamber)

Question 2

what are the two layers of the cornea?

Answer 2

1. epithelium

2. stroma

Question 3

properties of the epithelium in the cornea

Answer 3

lipophilic

hydrophobic

Question 4

properties of the stroma in the cornea

Answer 4

lipophobic

hydrophilic

Question 5

which drugs can penetrate both the epithelium and stroma of the cornea?

Answer 5

chloramphenicol

Question 6

what can be added to steroids to make them more hydrophobic?

Answer 6

alcohol

acetate

Question 7

what can be added to steroids to make it more hydrophilic?

Answer 7

phosphate

Question 8

what are steroids used in to do with the eye?

Answer 8

post-op cataracts
uveitis
prevention of corneal graft rejection
immediately in temporal arteritis

Question 9

risks of steroids to do with the eye

Answer 9

cataracts

glaucoma

Question 10

what condition of the eye should you never give steroids to?

Answer 10

hepatic keratitis

needs antiviral cover- dendritic ulcer

Question 11

what is benzalkonium chloride?

Answer 11

antibacterial agent and preservative that can disrupt the lipid layer and is added to bimatoprost

Question 12

what happens if the dose of benzalkonium chloride is too high?

Answer 12

allergic reaction

reddening

Question 13

how can topical drugs be systemically absorbed when added to the eye?

Answer 13

tears go into the lacrimal sac and absorbed into nasopharynx

limited by punctal occlusion

Question 14

five options of glaucoma medication

Answer 14

1. prostanoid
2. beta blockers
3. CA inhibitors
4. alpha-2 agonists
5. parasympathomimetic

Question 15

what and why are prostanoids used in glaucoma?

Answer 15

latanoprost

prostaglandin-like regulates flow of fluid

Question 16

why are beta blockers used in glaucoma?

Answer 16

inhibit enzyme involved in aqueous humour production e.g. timolol

Question 17

When should you not give a topical beta blocker?

Answer 17

don’t give if on systemic beta blockers

Question 18

examples of CA inhibitors used in glaucoma

Answer 18

topical dorzolamide

systemic acetazolamide

Question 19

what are alpha-2 agonists

Answer 19

vasodilators e.g. brimonidine

Question 20

adverse of brimonidine

Answer 20

overwhelming fatigue

Question 21

example of parasympathomimetic

Answer 21

pilocarpine

Question 22

when are intravitreal injections used?

Answer 22

administering antibiotics
intra-ocular steroids
anti-VEGF

Question 23

action of local anaesthetics

Answer 23

blocks Na+ channels

Question 24

when are local anaesthetic used?

Answer 24

foreign body removal
tonometry (IOP measure)
corneal scraping
cataracts

Question 25

risks of local anaesthetic

Answer 25

corneal melt

Question 26

when is the diagnostic dye fluorescein used?

Answer 26

corneal abrasion
dendritic ulcers
leaks 
tonometry
nasolacrimal duct obstruction
angiography

Question 27

examples of mydriatics (dilators)

Answer 27

tropicamide

cyclopentolate

Question 28

how do mydriatics dilate the pupil?

Answer 28

block parasympathetic supply to the iris
causes cycloplegia (stops lens from focusing)

Question 29

side effects of mydriatics

Answer 29

blurring

AACG

Question 30

action of sympathomimetics

Answer 30

cause pupil to dilate by acting on the sympathetic system

Question 31

examples of sympathomimetics

Answer 31

atropine

phenylephrine

Question 32

side effects of vigabatrin

Answer 32

constricts fields

Question 33

side effects of ethambutol

Answer 33

optic nerve stops functioning- appears pale

Question 34

side effect of digoxin

Answer 34

affects ability to judge colour

Question 35

side effect of chloroquine

Answer 35

maculopathy- screening

Question 36

side effect of amiodarone

Answer 36

brown pigmentation of cornea