Pharmacology - Part 2 and 3

Question 1

What does an indirect drug mean?

Answer 1

Indirect drug means it does not bind to the receptor. It works by causing a release of a hormone or a chemical message.

Question 2

What does indirect excitatory mean?

Answer 2

Enhances/increases synaptic levels of neurotransmitters.

Question 3

What does indirect inhibitory mean?

Answer 3

Reduces synaptic levels of neurotransmitters.

Question 4

Where does the cholingeric drugs work on?

Answer 4

Work on the parasympathetic nervous system. PNS performs the rest and digest actions.

Question 5

Where does the adrenergic drugs work on?

Answer 5

Work on the sympathetic nervous system. SNS performs fight and flight responses. Uses epinephrine or norepinephrine as its neurotransmitter.

Question 6

What are the possible effect s of serotoninergic and dopaminergic drugs on the eyes and the vision?

Answer 6

Can produce predictable disturbances in the intraocular muscle activities i.e. change in accommodation.
Possible ADRs include angle closure glaucoma.
Can produce unusual visual experiences i.e. aura.
Some sertoninergic blocking drugs can make px drowsy and produce deficits in EOM control mechanism leading to blurred vision.
Some cholinergic blocking drugs causes disturbances to blinking activity.

Question 7

Where is histamine stored?

Answer 7

Mast cells

Question 8

Is there a histamine re uptake system?

Answer 8

No

Question 9

What are the possible effects of histamine on the eyes and vision?

Answer 9

Changes in the ability to concentrate on tasks that require a high degree of motor coordination i.e. driving.

Question 10

Where is GABA neurotransmitters found?

Answer 10

Nerve and Glial cells

Question 11

What happens to GABA after it has binded?

Answer 11

It unbinds from its receptors and is re absorbed into the Glial cells. There is NO re uptake system.

Question 12

List the 8 ways a drug can be administered?

Answer 12

1. Oral
2. Parental
3. Conjunctival
4. Nasal
5. Buccal
6. Epidermal
7. Rectal
8. Vaginal

Question 13

Why do we have different ways to take drugs?

Answer 13

To optimise the drug delivery to the target organ/site. To take maximum benefit from the boys natural circulation .

Question 14

What is first pass metabolism?

Answer 14

Drug taken oral route, absorbed into the body via the lining of the stomach and intestine. Goes into the blood vessels surrounding intestine and straight to the liver. From as small as 10% - 99% of the drug is metabolised by the liver within minutes of being absorbed.

Question 15

What is the quickest way to get a drug to a target site?

Answer 15

Parental - by injection straight into a tissue or blood stream.

Question 16

List the 4 ways drugs can be excreted from the body?

Answer 16

1. Kidney
2. Breast milk
3. Hair and Skin
4. Sweat, tears and saliva

Question 17

After an eyedrops is used, what is the normal absorption routine that occurs?

Answer 17

95% is normally drained down the naso lacrimal gland.
The other 5% is absorbed into the conjunctival epithelium and the corneal epithelium. The drug that is absorbed by the corneal surface is able to cross the epithelial barriers and diffuse into the stroma.

Question 18

What can fluorescein be used for?

Answer 18

Assessment of foreign bodies 
Assessment of tear film stability 
Assessment of corneal surface 
Assessment of intraocular pressure with contact tonometry
Assessment of tear flow

Question 19

What wavelength does fluorescein absorb?

a) 550nm
b) 490nm
c) 640nm

Answer 19

ANSWER B

a) is rose bengal
b) is fluorescein
c) is lissamine green

Question 20

What grading scheme can be used for the assessment of dry eyes?

Answer 20

Van Bijesterveld with >3.5 being considered dry eyes.

Question 21

Give an example of another dye that is not fluorescein, rose bengal or lissamine green?

Answer 21

Phenol red
Methylene Blue
Brilliant blue FCF

Question 22

What does an anaesthetic do?

Answer 22

Blocks the neural transmission of ‘pain’.

Question 23

What are the two most important groupings for anaesthetics?

Answer 23

P-aminobenzoic esters

Benzoin acid amides

Question 24

What can anaesthetics be used for?

Answer 24

To examine an irritated/painful/injured eye
To allow contact procedures such as goldmann
To help in the initial fitting of a rigid contact lens
To facilitate procedures such as punctual plugging

Question 25

What do we use Mydriatics for?

Answer 25

To facilitate the examination of the inside of the eye.

Question 26

Using a mydriatics, what size of pupil should be achieved?

a) 4mm
b) 8mm
c) 6mm

Answer 26

ANSWER C

Question 27

How long after mydriatic use should you be able to drive?

Answer 27

1 - 2 hours

Question 28

What does a cycloplegic drug do to the eye?

Answer 28

Its relaxes the ciliary muscles which means accommodation fully relaxed.

Question 29

What do we use cycloplegia drug for?

Answer 29

To find the ‘true’ refractive error of the eye.

Question 30

Who do we use a cycloplegia drug for?

Answer 30

Latent hypermetropia
Anisometropia
Non - cooperative Patient
Young children