Lecture 12 - Medical Management of Glaucoma 3

Question 1

What is the mechanism of action for Osmotic drugs?

Answer 1

Lower IOP by increasing osmotic gradient between blood and ocular fluids

Note: Blood osmolality increased by up to 20 to 30 Osm/L. You will also transfer leading to reduction of vitreous volume

Question 2

What two influences will cause an increase in permeability?

Answer 2

Inflammation and congestion

Question 3

What drug is restricted to extracellular fluid space, has a greater effect on blood osmolality?

Answer 3

Mannitol

Note: At same dose, blood osmolality is LESS affected by drugs distributed in total body water (UREA)

Question 4

True or False. Ingestion of fluids after osmotic drug use Increases blood osmalility.

Answer 4

False. It will decrease.

Question 5

What two changes are made to change the blood osmolality?

Answer 5

1. Total dose administered
2. Weight of Pt.

Note: IV administration is more rapid

Question 6

When should you use osmotic drugs?

Answer 6

Short term treatment of acute and marked elevation of IOP

Question 7

What will oral glycerol do to blood glucose levels in a DM pt?

Answer 7

Rise in blood glucose levels

Question 8

What is the best way to make glycerol solution palatability?

Answer 8

Pour over ice

Question 9

Why should Mannitol be stored at room and not refrigerated?

Answer 9

Crystals will form, which will become higher in concentration

Note: Mannitol is a IV administered drug

Question 10

IOP rebound may be less common with glycerol and mannitol, why is that?

Answer 10

Poor ocular penetration

Question 11

What type of drug is a main stay in treatment for ACG?

Answer 11

Osmotic drugs

Question 12

When you dehydrate the vitreous, what happens to the lens and iris?

Answer 12

Move posteriorly and deeping the anterior chamber

Question 13

Even though ACG is linked to nausea, what will isosorbide do compared to glycerol?

Answer 13

Reduce nausea but will more likely cause you watery poops!

Had to throw in a fun joke!

Question 14

What drug do you want to use for Secondary Glaucoma?

Answer 14

Isosorbide and Glycerol???

Question 15

With the usage of glycerol, what two issues may occur in DM pts?

Answer 15

Hyperglycemia and Ketosis

Question 16

What oral osmotic drug will induce hypotonic diuresis (prolong and increase osmotic gradient)?

Answer 16

Ethyl Alcohol

Dehydration will also be caused

Question 17

Mannitol is a IV drug, what is a characteristic of an IV drug in comparision to ocular drugs?

Answer 17

Poor penetration of the cornea

Note: better penetration occurs when the eye is inflamed

Question 18

True or False. During pregnancy, the mother’s hemodynamics will increase episcleral venous pressure.

Answer 18

False. It will decrease

Question 19

During pregnancy, what will metabolic acidosis do?

Answer 19

affects Aqueous production and decreases IOP

Question 20

What major glaucoma drug is known to cause an abortion when administered as Periuterine?

Answer 20

Prostaglandin analogs

Question 21

What are the FDA safety Categories?

Answer 21

Class A – established safety record
Class B – animal safety data but no human data to confirm (Brimonidine and Nonspecific adrenergic agonist)
Class C – either animal studies with adverse effects or no human or animal data
(Most glaucoma drugs)
Class D – clear risks
Class X – known to cause birth defects and should never be used during pregnancy

Question 22

What happened when Prostaglandin analogs were given to pediatric pts and what was there reponse?

Answer 22

Majority did not respond to the therapy

Question 23

Complete the following sentence.

As in adults, systemic level of _______ can be found in pediatric pts after topical dosing but much ________ levels

Answer 23

Timolol and Higher

Question 24

What may prolong half life of medications in children by a factor of 2 to 6?

Answer 24

Lower levels of metabolic enzymes

Question 25

What concentration level is better to have in younger pts, using timolol?

Answer 25

0.5% Timolol than 0.25%

Question 26

What two health concerns can CAI’s do to pediatric pts?

Answer 26

Growth retardation and metabolic acidosis

Question 27

Which drug is better than most glaucoma drugs. This drug will reduce IOP and improve corneal edema?

Answer 27

Acetazolamide - Topical (side effects are lower)

Note: Pediatric glaucoma is best intervened with surgery, by clearing the cornea

Question 28

Which alternative medication may lower IOP by an osmotic effect?

Answer 28

Vitamin C (ascorbate)