Pharmacology

Question 1

Epithelium is ….. therefore …. soluble drugs penetrate the epithelium

Answer 1

epithelium is lipophilic/hydrophobic therefore lipid soluble drugs penetrate the epithelia

Question 2

Stroma is …. therefore …. soluble drugs penetrate the stroma

Answer 2

stroma is lipophobic/hydrophilic therefore water soluble drugs penetrate stroma

Question 3

Chloramphenicol is both …. & …..

Answer 3

lipophilic and hydrophilic

Question 4

ocular surface inflammation can …. the hydrophobic nature of the epithelium and ….. penetration

Answer 4

ocular surface inflammation can reduce the hydrophobic nature of the epithelium and increase penetration

Question 5

Dry eyes … penetration?

Answer 5

Aid

Question 6

Hydrophilic drugs are limited by the …

Answer 6

epithelium

Question 7

Hydrophobic drugs are limited by the ….

Answer 7

stroma

Question 8

Adding ……. or …… to a steroid makes it more ….. and allows penetration of the ……

Answer 8

Adding alcohol or acetate to a steroid makes it more hydrophobic and allows penetration of the epithelium

Question 9

Adding ……. to a steroid makes it more ….. and allows penetration of the ……

Answer 9

Adding phosphate to a steroid makes it more hydrophyllic and allows penetration of the stroma

Question 10

Describe prednisolone acetate

Answer 10

Hydrophobic
Good penetration of cornea
Used post-op

Question 11

Describe prednisolone phosphate

Answer 11

Hydrophilic
Poor penetration of un-inflamed cornea
Used for cornea disease or for low dose steroid

Question 12

What is belzalkonium chloride?

Answer 12

Used as surfactant

Antibacterial agent

Aids penetration of hydrophilic drugs

Question 13

What does benzalkonium cause?

Answer 13

Dry eye, disruption of tear film

Question 14

What is bimatoprost?

Answer 14

IOP lowering drug containing benzalkonium

Question 15

How can systemic absorption of topical drugs be reduced?

Answer 15

-punctual occlusion

pinch tear duct for 5 minutes and then close eye; useful when using drugs like B blockers

Question 16

Describe subtenons drug administration

Answer 16

fibrous layer which starts at limbus and regresses with age

drugs enter back of orbit

Question 17

What can’t be used in intravitreal injections?

Answer 17

Toxic drugs

Question 18

When is intravitreal injection used?

Answer 18

Endophthalmitis

Question 19

What is the benefit of intracameral injection?

Answer 19

Can use high dose steroids without systemic effect

Question 20

What drugs are used to treat infection?

Answer 20

Chloramphenicol 
Aciclovir (zovirax)
Flucloxacillin (Exocin)
Dexathametasone (maxidex)
Prednisolone

Question 21

When are steroids used topically?

Answer 21

1. post-op cataracts
2. uveitis
3. to prevent corneal graft rejection
4. temporal arteritis

Question 22

When are topical NSAIDs used?

Answer 22

pain relief eg post refractive laser

given in patients with macular oedema

corneal abrasion

Question 23

What are anti-histamines used for?

Answer 23

Hay fever

Question 24

What are mast cell stabilisers used for?

Answer 24

Uncontrolled allergic eye disease

Question 25

How does pilocarpine work?

Answer 25

parasympathomimetic, open up drain | glaucoma

Question 26

How does acetazolamide work?

Answer 26

carbonic anhydrase inhibitors, reduce aqueous production | glaucoma

Question 27

How does xalatan (lantanoprost) work?

Answer 27

Open drain | glaucoma

Question 28

How does timolol work?

Answer 28

b blocker; turn off tap by blocking b receptors in ciliary body

Question 29

What are the local side effects of steroids?

Answer 29

cataract glaucoma exacerbation of viral infection

Question 30

What are fluorescein drops used for?

Answer 30

- shows corneal abrasion - shows dendritic ulcer - identified leaks - tonometry - diagnosing nasolacrimal duct obstruction - angiography

Question 31

Name some dilating drops?

Answer 31

- atropine - phenylephrine - hydrochloride - tropicamide - mydrilate

Question 32

Which dilating drops block parasympathetic?

Answer 32

tropicamide, cyclopentolate

Question 33

How do sympathomimetic drugs work?

Answer 33

causes pupil to dilate (dilator pupillae)

Question 34

How do local aesthetics work?

Answer 34

Block sodium channel and impede nerve conduction

Question 35

When are local anaesthetic drops used?

Answer 35

- FB removal - tonometry (IOP measurement) - corneal scraping - comfort - cataract surgery

Question 36

What shouldn't be given in herpetic keratitis

Answer 36

steroids

Question 37

What does vigabatrin cause?

Answer 37

Anticonvilsant which causes irreversible contraction of visual field

Question 38

What can ethambutol cause?

Answer 38

Optic neuropathy

Question 39

What does hydroxychloroquine at high doses cause?

Answer 39

Maculopathy

Question 40

What does amiodarone cause?

Answer 40

Vortex keratopathy (brown pigmentation of epithelium of cornea)