Lec.12: Medical Management of Glaucoma 3

Question 1

what happens to the osmotic gradient if drugs penetrate the eye?

Answer 1

decreases

Question 2

when will the osmotic pressure be greater?

Answer 2

when there is less drug in the eye

Question 3

how is mannitol distributed and what effect does it have on blood osmolality?

Answer 3

restricted to extracellular fluid space. this has a greater effect on blood osmolality

Question 4

what is the result of increased blood osmolality?

Answer 4

loss of water from eye (due to hyperosmotic plasma)

Question 5

what is the effect on blood osmolality if a patient ingests fluids after taking an osmotic drug.

Answer 5

decreases blood osmolality

Question 6

which method of administration allows for more rapid and greater osmotic gradient due to bypassing the GI tract?

Answer 6

Intravenous

Question 7

what are the indications for osmotic drugs?

Answer 7

short term treatment of acute and marked elevation of IOP, angle-closure glaucoma, aqueous misdirection syndrome and secondary glaucoma

Question 8

what is aqueous misdirection syndrome?

Answer 8

aqueous humor gets pushed toward the vitreous. even if the anterior chamber appears normal the pressure will be high

Question 9

in what cases are osmotic drugs contraindicated?

Answer 9

anuria, severe dehydration, pulmonary edema, cardiac deompensation, renal/hepatic disease and hypervolemia (excess fluid in blood)

Question 10

what is the treatment regimen for isosorbide?

Answer 10

45% wt/vol solution, 1-2 g/kg of body weight and take 2-4 doses per day in the short term

Question 11

what can happen if mannitol is stored below room temperature?

Answer 11

crystals can form and lead to formation of emboli

Question 12

what affects does glycerol have on blood glucose?

Answer 12

cause rise in blood glucose levels (watch out for diabetics)

Question 13

how are isosorbide and glycerol administered?

Answer 13

oral

Question 14

what is the clinic use for osmotic drugs?

Answer 14

quickly lower IOP in event of angle closure glaucoma

Question 15

(T/F) isosorbide may cause less nausea and vomiting than glycerol and not metoblize to glucose?

Answer 15

true

Question 16

how many cal/g does glycerol produce?

Answer 16

4.34 cal/g

Question 17

where is glycerol metabolized?

Answer 17

80% in the liver and 20% in kidney

Question 18

what is the caloric load of isosorbide?

Answer 18

none

Question 19

what is the calorie load of ethyl alcohol?

Answer 19

7 cal/gm

Question 20

what induces hypotonic diuresis?

Answer 20

alcohol

Question 21

what drugs are administered intravenously?

Answer 21

mannitol and urea

Question 22

which IV drug experiences a greater rebound of IOP?

Answer 22

urea

Question 23

how is pediatric glaucoma usually treated?

Answer 23

surgically

Question 24

what is teratogenicity?

Answer 24

capability of producing fetal malformation

Question 25

what is a class D drug?

Answer 25

clear risk

Question 26

what is a class X drug?

Answer 26

known to cause birth defects and should never be used during pregnancy

Question 27

what is a class B drug?

Answer 27

animal safety data but no human data to confirm

Question 28

what is a class C drug?

Answer 28

either animal studies with adverse effects or no human or animal data

Question 29

what FDA class do most glaucoma drugs fall under?

Answer 29

class C

Question 30

what class does brimonidine belong too?

Answer 30

class B

Question 31

lower levels of metabolic enzymes prolong half-life of medications in children by how much?

Answer 31

factor of 2 to 6

Question 32

what concentration of timolol should be used on the young?

Answer 32

0.25%

Question 33

what can cause growth retardation and metabolic acidosis in children?

Answer 33

oral CAI’s

Question 34

which oral CAI is well tolerated by children in does of 5-15 mg/kg per day?

Answer 34

acetozolamide