Lecture 12 - Medical Management of Glaucoma 3 Flashcards
What is the mechanism of action for Osmotic drugs?
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
What two influences will cause an increase in permeability?
Inflammation and congestion
What drug is restricted to extracellular fluid space, has a greater effect on blood osmolality?
Mannitol
Note: At same dose, blood osmolality is LESS affected by drugs distributed in total body water (UREA)
True or False. Ingestion of fluids after osmotic drug use Increases blood osmalility.
False. It will decrease.
What two changes are made to change the blood osmolality?
- Total dose administered
- Weight of Pt.
Note: IV administration is more rapid
When should you use osmotic drugs?
Short term treatment of acute and marked elevation of IOP
What will oral glycerol do to blood glucose levels in a DM pt?
Rise in blood glucose levels
What is the best way to make glycerol solution palatability?
Pour over ice
Why should Mannitol be stored at room and not refrigerated?
Crystals will form, which will become higher in concentration
Note: Mannitol is a IV administered drug
IOP rebound may be less common with glycerol and mannitol, why is that?
Poor ocular penetration
What type of drug is a main stay in treatment for ACG?
Osmotic drugs
When you dehydrate the vitreous, what happens to the lens and iris?
Move posteriorly and deeping the anterior chamber
Even though ACG is linked to nausea, what will isosorbide do compared to glycerol?
Reduce nausea but will more likely cause you watery poops!
Had to throw in a fun joke!
What drug do you want to use for Secondary Glaucoma?
Isosorbide and Glycerol???
With the usage of glycerol, what two issues may occur in DM pts?
Hyperglycemia and Ketosis
What oral osmotic drug will induce hypotonic diuresis (prolong and increase osmotic gradient)?
Ethyl Alcohol
Dehydration will also be caused
Mannitol is a IV drug, what is a characteristic of an IV drug in comparision to ocular drugs?
Poor penetration of the cornea
Note: better penetration occurs when the eye is inflamed
True or False. During pregnancy, the mother’s hemodynamics will increase episcleral venous pressure.
False. It will decrease
During pregnancy, what will metabolic acidosis do?
affects Aqueous production and decreases IOP
What major glaucoma drug is known to cause an abortion when administered as Periuterine?
Prostaglandin analogs
What are the FDA safety Categories?
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
What happened when Prostaglandin analogs were given to pediatric pts and what was there reponse?
Majority did not respond to the therapy
Complete the following sentence.
As in adults, systemic level of _______ can be found in pediatric pts after topical dosing but much ________ levels
Timolol and Higher
What may prolong half life of medications in children by a factor of 2 to 6?
Lower levels of metabolic enzymes
What concentration level is better to have in younger pts, using timolol?
0.5% Timolol than 0.25%
What two health concerns can CAI’s do to pediatric pts?
Growth retardation and metabolic acidosis
Which drug is better than most glaucoma drugs. This drug will reduce IOP and improve corneal edema?
Acetazolamide - Topical (side effects are lower)
Note: Pediatric glaucoma is best intervened with surgery, by clearing the cornea
Which alternative medication may lower IOP by an osmotic effect?
Vitamin C (ascorbate)
