Pharmacology Flashcards Preview

Opthamology > Pharmacology > Flashcards

Flashcards in Pharmacology Deck (31)
Loading flashcards...
1
Q

Is the epithelium lipophilic/phobic?

A

lipophilic

2
Q

Is the stroma lipophilic/phobic?

A

phobic

3
Q

Give an example of a drug which has both lipophilic and phobic properties, allowing it to easily penetrate the cornea.

A

chloramphenicol

4
Q

What can reduce the hydrophobic nature of endothelium?

A

ocular surface inflammation

5
Q

What makes a steroid more hydrophobic?

A

alcohol/acetate

6
Q

What makes a steroid more hydrophilic?

A

phosphate

7
Q

Is prednisolone acetate hydrophobic or philic?

A

hydrophobic

8
Q

Does prednisolone acetate have good or bad penetration in uninflamed cornea?

A

good penetration

9
Q

When is prednisolone acetate used?

A

post op

10
Q

What is Prednisolone phosphate used for?

A

for cornea disease or when want low dose steroids

11
Q

What is Benzalkonium?

A

Benzalkonium is a preservative.
Also disrupts lipid layer of tear film
Aids penetration of some drugs

12
Q

What is Bimatoprost?

A

Drug used to lower IOP in glaucoma

13
Q

What are the 3 broad categories of antibiotics used on the eye?

A

3 broad categories - all act on bacteria and either
Inhibit protein synthesis
Inhibit cell wall synthesis
Inhibit nucleic acid synthesis

14
Q

What is the most commonly used topical antibiotic?

A

chloramphenicol

15
Q

What are the side effects of chloramphenicol?

A

Allergy
Irreversible aplastic anaemia (rare : 1 in 40,000)
Grey baby syndrome

16
Q

Describe antibiotics that inhibit nucleic acid synthesis

A

Quinolones e.g. ofloxacin, inhibit DNA gyrase, an enzyme that compresses bacterial DNA into supercoils

Inhibition of DNA gyrase leads to unwinding of supercoils and cell death

17
Q

Describe antibiotics that inhibit cell wall synthesis.

A

Penicillins & cephalosporins have common B lactam ring
B lactam ring inhibits enzyme which makes bacterial cell wall
Without cell wall, bacteria die

18
Q

How does chlorampheniocol work?

A

inhibits bacterial protein synth via ribosomes

19
Q

Describe the antiviral drug zovirax and say what it is used for.

A

Zovirax inhibits viral DNA synthesis
Base analogue (mimics guanine)
Used for dendritic ulcers of the cornea

20
Q

List 4 anti inflammatory agents.

A

Steroids
Topical NSAIDs
Anti-histamines
Mast cell stabilisers

21
Q

What are steroids used in the eye for? (3 things)

A

1) post op cataracts
2) uveitis
3) to prevent corneal graft rejection

22
Q

List the local side effects of steroids.

A

cataract
glaucoma
exacerbation of viral infection

23
Q

What is intravitreal injections used for?

A

Used as method of administration of antibiotics in endophthalmitis
and used to deliver intra-ocular steroids

24
Q

How does local anaesthetic work?

A

Blocks sodium channels and impedes nerve conduction

25
Q

What is the most commonly used dye in the eye and what might it be used for.

A

fluorescein

1) seeing a corneal abrasion
2) tonometry
3) diagnosing nasolacrimal duct obstruction
4) angiography

26
Q

How do Mydriatics work?

A

Cause pupil dilation by blocking parasympathetic supply to iris

27
Q

Give examples of mydriatics.

A

tropicamide, cyclopentolate

28
Q

What are mydriatics side effects?

A

blurring, AACG (acute angle closure glaucoma)

29
Q

Describe how Sympathomimetics work and give examples.

A

Acts on sympathetic system
Causes pupil to dilate
Do not affect the ciliary muscle (accomodation)
E.g phenylephrine, atropine

30
Q

What treatments are used for glaucoma?

A

Prostanoids
Beta blockers
Carbonic anhydrase inhibitors
(‘Trusopt’) or systemic – acetazolamide (Diamox)
Alpha2 adrenergic agonist
Parasympathomimetic - pilocarpine
Combination - (dorzolamide and timolol - Cosopt ).

31
Q

What might Vigabatrin do?

A

constrict fields