Lecture 12 Medical mgmt part 3 osmotics/pediatrics/FDA categories

Question 1

Which one of the following is NOT true regarding osmotic drugs?

a) They are frequently used for long term reduction in IOP
b) They lower IOP by increasing osmotic gradient between blood and ocular fluids
c) They are indicated for use in acute and extreme cases of angle closure and secondary glaucoma
d) they are used in preoperative preparation

Answer 1

a) They are frequently used for long term reduction in IOP (false–they are used infrequently for short-term reduction of IOP)

Question 2

Upon administration of of osmotic drugs, the osmolality is ______

a) decreased
b) increased
c) osmotic drugs don’t change osmolality

Answer 2

b) increased (a loss of water cause an increase in solute to solution concentration)

Question 3

(T/F) Drugs entering the eye rapidly produce less of an osmotic gradient than those that penetrate slowly or not at all.

Answer 3

true. (increasing osmotic gradient lowers IOP, a drug that penetrates will not help lower IOP as well as one that does not penetrate)

Question 4

(T/F) Osmotic gradient between retina-choroid and vitreous causes water transfer leading to reduction of vitreous volume

Answer 4

true

Question 5

Which one of the following is NOT one of the 7 factors that effect osmotic gradient?

a) ocular penetration
b) distribution of body fluids
c) molecular weight and concentration
d) rate and route of administration
e) systemic diseases
f) rate of systemic clearance
g) type of diuresis

Answer 5

e) systemic diseases (i just threw that in there, it may or may not effect osmotic gradient to some extent, but the key here is to look for solute to solution concentration type factors)

Question 6

Which one of the following is NOT true regarding osmotics?

a) ethyl alcohol enters aqueous rapidly, but slow penetration in the avascular vitreous
b) permeability is greatly increased with inflammation and congestion
c) drugs with low solubility require lower volumes of solution
d) drugs restricted to extracellular space (mannitol) have a greater effect on blood osmolality
e) at the same dose, blood osmolality is less affected by drugs distributed in total body water (urea)

Answer 6

c) drugs with low solubility require lower volumes of solution (false, they require larger volumes of solution. Ingestion of fluids after osmotic drug use decreases blood osmolality)

Question 7

Which one of the following is NOT true regarding osmotics?

a) change in blood osmolality depends on total dose administered and weight of patient
b) intravenous administration bypasses absorption from GI tract providing more rapid and greater osmotic gradient compared with oral administration
c) Osmotics can be used in cases of aqueous misdirection
d) Osmotics can be used in cases of severe dehydration

Answer 7

d) Osmotics can be used in cases of severe dehydration (false, osmotics pull water out to lower pressure, it is contraindicated in pts with severe dehydration)

Question 8

Which one of the following is NOT a contraindication of osmotic use?

a) cardiac, renal, or hepatic diseases
b) the osmotic, glycerol, should not be used in diabetic pts
c) pts with anuria or those with severe dehydration
d) pulmonary edema, congestive heart disease
e) should not be used in pts with hypervolemia (excess fluid in blood)
f) all of the above are contraindications for osmotic use

Answer 8

f) all of the above are contraindications for osmotic use

Question 9

Which one of the following is NOT considered an osmotic drug?

a) glycerol
b) isosorbide
c) mannitol
d) methocarbamol
e) ethyl alcohol
f) urea

Answer 9

d) methocarbamol (that’s a muscle relaxer)

* ethyl alcohol is not really prescribed but works as an osmotic to reduced water in the eye, thus reducing IOP.

Question 10

Match the following:

1) glycerol
2) isosorbide
3) mannitol

a) below room temperature, forms crystals
b) not good for diabetic pt’s
c) should include use of a filter
d) these 2 are given orally
e) this one is given IV
f) most likely to cause diarrhea
g) most likely to cause nausea and vomiting

Answer 10

a) below room temperature, forms crystals–3) mannitol
b) not good for diabetic pt’s–1) glycerol
c) should include use of a filter–3) mannitol
d) these 2 are given orally–1) glycerol and 2) isosorbide
e) this one is given IV–3) mannitol
f) most likely to cause diarrhea–2) isosorbide
g) most likely to cause nausea and vomiting–1) glycerol

• *IV mannitol is ideal for pt’s experiencing nausea and vomiting, which is common during angle closure
• *isosorbide

Question 11

Match the following:

1) glycerol
2) isosorbide
3) mannitol

a) has good ocular penetration
b) has poor ocular penetration
c) has very poor ocular penetration

Answer 11

a) has good ocular penetration–2) isosrbide
b) has poor ocular penetration–1) glycerol
c) has very poor ocular penetration–3) mannitol

*remember “very poor” ocular penetration is best

Question 12

(T/F) It would be best to give IV mannitol first, if not possible then glycerol, if not possible (because they were diabetic) then isosorbide

Answer 12

true

• *order from best to least best: mannitol, glycerol, isosorbide
• *order from poorest penetration to best penetration: mannitol, glycerol, isosorbide

Question 13

Why are osmotics indicated for cases of aqueous misdirection?

Answer 13

because they temporarily dehydrate the vitreous, allowing the iris and lens to shift posteriorly, opening up the anterior chamber

Question 14

Which one of the following is NOT a use for an osmotic drug?

a) highly elevated IOP
b) uveitic and post-traumatic glaucoma
c) preoperative use in eyes with extremely high IOP that require glaucoma surgery
d) all of the above are indications of osmotic use

Answer 14

d) all of the above are indications of osmotic use

Question 15

Which of the following is NOT true regarding glycerol?

a) onset of action is 10-30 minutes
b) maximal effect is 45-120 minutes
c) duration of action is 4-5 hours
d) 80% of metabolism occurs in liver and 10-20% occurs in kidney
e) all of the above are correct

Answer 15

e) all of the above are correct

Question 16

Which of the following is NOT true regarding isosorbide?

a) osmotic effect persists for up to 5-6 hours
b) 2 to 4 doses per day for short term use
c) 1-2 g/kg of body weight
d) 45% wt/vol solution
e) all of the above are correct

Answer 16

e) all of the above are correct

Question 17

Which of the following is NOT true regarding Mannitol?

a) onset of action 10-30 minutes
b) peak effect 30-60 minutes
c) duration of action 4-6 hours
d) large volume of IV fluid required due to limited solubility
e) all of the above are correct

Answer 17

e) all of the above are correct

**mannitol is the drug of choice, however, most OD’s cannot administer it

Question 18

Which of the following is NOT true regarding Ethyl alcohol?

a) Oral dose for lowering IOP 2-3 ml/kg of body weight of a 40-50% solution
b) rapidly absorbed
c) distrobution in total body wtaer and rapid penetration of eye limit degree and duration of osmotic gradient
d) alcohol induces hypotonic diuresis and prolongs/increases osmotic gradient
e) all of the above are correct

Answer 18

e) all of the above are correct

Question 19

(T/F) IOP rebound is less common with isosorbide since it has good ocular penetration

Answer 19

false. (IOP rebound is less common with mannitol and glycerol since they have poor ocular penetration)

Question 20

(T/F) In cases of extremely high IOP, the iris sphincter does not function due to ischemia (loss of blood supply/oxygen), and in such cases, osmotics can provide a rapid reduction of IOP.

Answer 20

true

Question 21

Which of the following are NOT side effects of osmotics?

a) ocular: IOP rebound/intraocular hemorrhage
b) GI: nausea/vomiting/diarrhea
c) CNS: headache/chills/fever/thirst/lethargy/confusion
d) cardiovascular: angina/pulmonary edema/congestive heart failure
e) GI: diuresis/electrolyte imbalance/anuria/dehydration/hypervolemia
f) all of the above are side effects of osmotics

Answer 21

f) all of the above are side effects of osmotics

Question 22

Which of the following is NOT true regarding Urea?

a) osmotic effect is less pronounced
b) distributed in total body water
c) penetrates eyes more readily-especially when inflamed
d) greater rebound of IOP
e) All of the above are true

Answer 22

e) All of the above are true

Question 23

(T/F) Pediatric glaucoma is treated primarily surgically and medications are usually supportive

Answer 23

true

Question 24

(T/F) Pregnancy tends to cause an increase in IOP

Answer 24

false (tends to be lower than before pregnancy. Episcleral venous pressure decreases due to changes in mother’s hemodynamics. average decrease of IOP is 1.5mmHg during pregnancy. Metabolic acidosis affects aqueous production and decreases IOP)

Question 25

(T/F) Prostaglandin analogs are in a class of prostaglandins that may cause abortion when administered via periuterine injection

Answer 25

true (even though you would need 400ml of latanoprost, which is like 160 bottles to be equivalent to the dosage that causes abortion, err on the side of caution, just do not use PG’s with pregnant women)

Question 26

Which 2 glaucoma meds are class B?

a) brimonidine and cholinergics
b) nonspecific adrenergic agonists and apraclonidine
c) brimonidine and nonspecific adrenergic agonists
d) apraclonidine and brimonidine

Answer 26

c) brimonidine and nonspecific adrenergic agonists (the rest are all class C)

Question 27

(T/F) The following a list of all class C glaucoma meds?

1) PG’s
2) OBB’s
3) A-2-agonist: apraclonidine
4) CAI’s
5) fixed combo timolol-dorzolamide
6) cholinergics

Answer 27

true

Question 28

Match the following:

1) class A
2) class B
3) class C
4) class D
5) class X

a) clear risks
b) known to cause birth defects and should never be used in pregnancy
c) established safety record
d) either animal studies with adverse effects or no human or animal data
e) animal safety but no human data

Answer 28

1) class A–c) established safety record
2) class B–e) animal safety but no human data
3) class C–d) either animal studies with adverse effects or no human or animal data
4) class D–a) clear risks
5) class X–b) known to cause birth defects and should never be used in pregnancy

Question 29

(T/F) Regarding glaucoma therapy during lactation: any medication with any degree of systemic absorption must be assumed to have a measurable level in breast milk

Answer 29

true (not many studies done. Timolol and Betaxolol was not of concern if infant had normal renal and hepatic function)

Question 30

(T/F) Studies were done with PG’s and OBB’s used in pediatric glaucoma pt’s and the majority did not respond to therapy.

Answer 30

true

Question 31

(T/F) Pediatric pt’s are overall more vulnerable to side effects of mediactions

Answer 31

true

Question 32

(T/F) In pediatric pt’s, CAI’s can cause growth retardation and metabolic acidosis and topical treatment is preferred to oral treatment

Answer 32

true, the side effects are lower with topical treatment

Question 33

(T/F) There is no evidence that exercise helps lower IOP, do not recommend to pt, they could hurt themselves and blame you

Answer 33

true

Question 34

Which one of the following is NOT an alternative to lowering IOP?

a) ginko biloba/ bilberry
b) taurine/ magnesium
c) marijuana/ magnesium
d) vitamin C and B12
e) all of the above may lower IOP even though there is no scientific studies that support it

Answer 34

e) all of the above may lower IOP even though there is no scientific studies that support it