Week 3: Glaucoma & Contraceptives Flashcards
What is the only modifiable risk factor for glaucoma?
IOP- balance between the rate of formation of aqueous humor and amount of resistance to its outflow
What is 90-95% of all primary glaucoma?
primary open angle (POAG)
Primary open angle glaucoma is ____ progressive and found in pts greater than 50 years old
slowly
What type of glaucoma is 10% of all primary cases?
primary angle closure
Why is primary angle closure treated as an emergency?
to avoid vision loss
What are the most common agents that are used in glaucoma?
beta-adrenergic blocking agents (beta blockers)
What is the MOA of beta blockers in glaucoma?
acts on beta 2 receptors in the ciliary processes which leads to reduction of aqueous humor production
How can systemic SEs be decreased when using beta blockers?
using punctual occlusion (holding lacrimal duct for 3-5 minutes)
What is the first line medication for glaucoma unless contraindicated?
beta blockers
caps are yellow or blue
What is significant about beta blocker, Betaxolol (Betopic S)?
does not lower the IOP as much as other products but has shown positive influence on visual fields
What beta blockers is the gold standard in treatment for glaucoma?
timolol solution (Timoptic)
timolol solution (Timoptic) is ______ .
non selective
timolol solution (Timoptic) gel forming solution is administered how often?
once a day
What is the MOA of adrenergic agents- sympathomimetics?
acts on both alpha and beta receptors
alpha: decrease aqueous humor production
beta: increase in outflow
What are 2 names of adrenergic agents?
epinephrine (Glaçon, Epifrin)
Dipivefrin (Propine)
What are the systemic SE of adrenergic agents?
palpitations tachycardia headache anxiety increased sweating
What medication is a prodrug of epinephrine?
Dipivefrin
What is shown to be effective in combo with Dipivefrin?
combo with non selective beta blocker for a more pronounced IOP decrease
What is the MOA of selective alpha 2 agonists?
decrease aqueous production
alpha 2 selectivity presents release of norepinephrine into the synapse which decreases aqueous humor production and increase uveoscleral outflow
What are 2 examples of selective alpha 2 agonists?
Apraclonidine (Iopidine)
Brimonidine (Alphagan
When are selective alpha 2 agonists used?
in addition to other agents, if used at all
What selective alpha 2 agonist has additional 20% decrease in IOP but tachyphylaxis develops rapidly?
Apraclonidine (Iopidine)
When are Brimonidine (Alphagan) used?
Can be used alone in patients who are intolerant to beta blockers
What is the MOA of Cholinergics?
Stimulation of the sphincter pupillae in the iris
Causes miosis(reduces amount of light entering the eye and field of vision)
pulls open the meshwork pores through ciliary muscle contraction
Increased outflow
What cholingeric reduces IOP by 20-30%?
Pilocarpine
What are 2 examples of cholinergics?
Pilocarpine
Carbachol
What cholinergic is an elliptical device placed under upper part of lower lid and replaced every week?
Ocusert-slow release delivery system
What are the cholinesterase inhibitors? MOA?
anticholinesterase agents
binds to enzyme which breaks down endogenous acetylcholine
parasympathomimetics
When are anticholinesterases used?
used only in patients unresponsive or intolerant of other therapies
What is the MOA of carbonic anhydrase inhibitors? (CAIs)
inhibit carbonic anhydrase in ciliary body to decrease aqueous formation by 40-60%
What are examples of CAIs?
Dorzolamise (Trusopt)
Acetazolamide (Diamox)
How is Dorzolamise (Trusopt) given and how much does it reduce IOP?
topical
reduce by 15-26%
How is Acetazolamide (Diamox) given? How much does it reduce IOP?
Oral
Reduce by 25-40% Higher incidence of SEs
What are the 3 medications of choice for glaucoma?
- beta blockers
- Prostaglandin F2 alpha analogues
- Carbonic Anhydrase Inhibitors (CAIs)
What is the MOA of Prostaglandlin F2 alpha analogues?
Increase uveoscleral outflow of aqueous humor
What are the SEs of Prostaglandin F2 alpha analogues?
fewer systemic effects compared to TImolol
iris pigmentation by 7-16%
eyelash thickening
How effective are Prostaglandin F2 alpha analogues at decreasing IOP?
similar to beta blockers if not more