Special Senses Pharmacology

Question 1

What part of eye health is the lacrimal functional unit responsible for?

Answer 1

Surface ocular health

Question 2

What does CALT stand for?

Answer 2

Conjunctival Associated Lymphoid Tissue

Question 3

Give three functions of CALT

Answer 3

Recruit immune cells with chemical mediators.
Activate complement cascade.
Identify and remove foreign substances.

Question 4

Which part of the eye would you usually use topical medication in?

Answer 4

The surface and anterior segment.

Question 5

Which part of the eye would you have to use topical medication to treat?

Answer 5

Surface and anterior segment

Question 6

What should the pH of topical medications be for the eye?

Answer 6

4.5-9 but a normal tear pH of 7.4 is best.

Question 7

What are the two main routes that topical medication penetrates the eye with? What do they rely on to work?

Answer 7

Transcellular (relies on lipophilic-hydrophilic balance) and paracellular (relies on small molecular weight).

Question 8

What part of the eye is prednisolone sulphate used to treat and where is it contraindicated?

Answer 8

Used to treat surface disease but contraindicated in corneal ulceration.

Question 9

List two ways of improving topical penetration.

Answer 9

Combining drugs with organic salts.
Addition of preservatives.

Question 10

How could you improve the tear retention of a drug?

Answer 10

Suspended particles

Question 11

How does the size of a particle relate to retention time in the eye?

Answer 11

The smaller the particle, the shorter the retention time.

Question 12

What is the maximum volume that the palpebral fissue can hold?

Answer 12

25-30uL - one drop is plenty!

Question 13

How long does it take for a drop of drug to be cleared from the eye?

Answer 13

Tear turnover rate is 1uL/min so 1 drop is cleared in 10 mins

Question 14

How long will a solution of a subconjunctival injection last?

Answer 14

8-12 hours

Question 15

How would a sustained release implant be administered and name a drug that may be used in this way?

Answer 15

Drug with a silicone vehicle injected subconjunctivally/episcleral. An example of this would be cyclosporine.

Question 16

Name two conditions that could be treated with a sustained release implant.

Answer 16

Equine recurrent uveitis.
Keratoconjuctivitis Sicca.

Question 17

List three bacteriostatic antibiotics that are commonly used for eye treatments.

Answer 17

Chloramphenicol
Fusidic Acid
Tetracyclines

Question 18

List three bactericidal antibiotics that are commonly used for eye treatements

Answer 18

Aminoglycosides
Fluoroquinolones
Penicillins

Question 19

What is the mode of action of most antifungals and antivirals used in cells? (static or cidal)

Answer 19

Static

Question 20

List two drug classes that would be contraindicated with conreal ulceration.

Answer 20

Corticosteriods and NSAIDs

Question 21

List three types of antiglaucoma drugs.

Answer 21

Prostaglandin analogues
Carbonic anhydrase inhibitors
Beta blockers

Question 22

Give two examples of prostaglandin analogues used for the treatment of glaucoma.

Answer 22

Iatanoprost, travoprost

Question 23

Give two examples of carbonic anhydrase used for the treatment of glaucoma.

Answer 23

Dorzolamide, brinzolamide

Question 24

Give two examples of beta blockers used for the treatment of glaucoma.

Answer 24

Timolol, betaxolol

Question 25

Give two drugs used as mydriatics and what is their duration?

Answer 25

Atropine - 3-14 days
Tropicamide - 6-8 hours

Question 26

What does cycloplegia mean?

Answer 26

Paralysis of the ciliary muscle, meaning there is no accomodation.

Question 27

Which mydriatic is more cycloplegic (drugs that paralyse the ciliary muscles and cause relaxation of accommodation)?

Answer 27

Atropine

Question 28

List four local anaesthetics used in the eyes.

Answer 28

Proxymetacaine, tetracaine, lignocaine and bupivicaine.

Question 29

Which local anaesthetic used in the eyes is the most potent and has the longest duration of action?

Answer 29

Bupivicaine (lasts 5-10 hours)

Question 30

What are the four types of tear replacements that are used?

Answer 30

Aqueous substitutes, mucinomimetics, viscoelastics, lipid based substitutes.

Question 31

How does cyclosporine work in the eyes and what is the name and concentration of the formulation?

Answer 31

Blocks activation of T cells.
0.2% ointment.

Question 32

List four anti-collagenases for the eye.

Answer 32

Serum + plasma.
EDTA
Acetylcysteine
Tetracyclines.