Glaucoma Flashcards
glaucoma therapeutics acting via parasympathetic NS stimulate what receptors?
muscarinic receptors
glaucoma therapeutics acting via sympathetic NS stimulate which receptors?
alpha 1, 2 or inhibit beta 2
why are sympathomimetics not used orally for IOP reduction?
they are rapidly metabolized by first pass effect in liver and intestine - do not readily cross the BBB
which sympathomimetics mildly decrease aqueous production?
aproclonidine
which sympathomimetic is most effective at decreasing aqueous production?
Brimonidine
what are the most common side effects to aproclonidine?
xeroma (dry mouth) and dry nose
do beta blockers (sympatholytics) or sympathomimetics affect IOP at night?
no - sympathetic tone is considered inactive during sleep
which drug is the gold standard for reduction of IOP?
Timolol (decreases 25% in IOP)
which drug stabilizes membrane excitability and is used to treat cardiac arrhythmias?
metipranolol
which is the “safest” beta-blocker for asthma and has putatuve neuro-protection potential?
Betaxolol (betaoptic) = targets beta1 only
precautions should be taken with the use of beta blockers in which types of patients?
hyperthyroidism, myasthenia gravis, ACG, anesthesia, aphakia and diabetes
what type of agonists stimulate ciliary body longitudinal smooth muscle ACh muscarinic receptors directly or indirectly?
parasympathomimetic cholinergic agonists
which CAI drug is the best ocular penetrating agent?
methazolamide because it is the least ionic
which PG analog would you use if you wanted to avoid BAK toxicity?
Zioptan (Tafluprost)
which PG analog causes orbital fat degredation?
Bimatroprost (it inhibits adipocyte differentiation and survival)
what is the mechanism of action for hyperosmotic agents?
transfer fluid from eye to circulation to quickly drop IOP in ACG attacks
which receptor type will you not want a glaucoma drug to be selective for?
nicotinic - there are none in the eye involved in IOP
do alpha2 agonists work better in the day or night?
day while awake - sympathetic system is down while you sleep
which alpha2 agonist is used in long-term treatment? which is only post-op?
brimonidine (alphagan-P) for long term and apraclonidine (short term)
which beta blocker causes the least amount of corneal anesthesia?
Timolol
which parasympathometic is the only one to be more selective towards muscarinic receptors?
pilocarpine
pilocarpine is indicated for what conditions?
OAG and angle closure glaucoma
why is pilocarpine better suited for old people?
presbyopic - drug physically stimulates ciliary body and move it, may cause a ciliary spasm in younger people
describe how carbonic anhydrase inhibitors work?
reversible non-competitive inhibitor of ciliary body CA - decreases bicarbonate ions
what are the two topical CAIs and what can they treat besides OAG?
Brinzolamide (susp) and Dorzolamide (soln) - both can treat HTN
what oral CAI is best at penetrating the eye and why?
methazolamide - least ionic and has a long duration
why might CAIs cause transient myopia?
causes swelling in ciliary body which displaces lens/iris
prostaglandin analogs mimic which prostaglandin?
PGF2a
which PG is preservative free?
zioptan (tafluprost)
what makes PG analogs the 1st line of therapy for OAG?
used once per day at bedtime
most PG analogs stimulate the FP receptor on ciliary muscle except one - which one and how?
Brimatoprost (lumigan) - at trabecular meshwork it increases uveoscleral outflow
which 3 types of glaucoma therapeutics inhibit aqueous production?
alpha-adrenergics, beta-blockers, and CAIs
which 2 types of glaucoma therapeutics increase TM outflow?
alpha-adrenergics and miotics
which 2 types of glaucoma therapeutics increase uveoscleral outflow?
alpha-adrenergics and prostaglandins
what are 2 selective sympathomimetic agents? and what are they selective for?
apraclonidine (+a2>1) and brimonidine (+a2»1)
what type of preservative does Brimonidine have?
Purite ‘disappearing’ preservative - light inactivated
what side effect is the reason selective sympathomimetics are only used for short term?
tachyphylaxis (rapidly developing resistance) = most common in alpha2 agoninsts
what are the 5 beta-blockers (sympatholytics)?
metipranolol, timolol, betaxolol, levobunolol, carteolol
which category of glaucoma therapeutics can cause corneal anesthesia?
beta blockers
what is the only parasympathomimetic agent still used and is selective for muscarinic receptors?
pilocarpine
which glaucoma therapeutic category are sulfonamides?
carbonic anhydrase inhibitors
what are the 2 topical CAIs?
Brinzalamide and Dorzolamide
what are the 5 CAI’s?
acetazolamide, brinzalamide, methazolamide, dichlorphenamide, dorzolamide
what are the 4 topical prostaglandin analogs?
latanoprost, travoprost, bimatoprost, tafluprost
what are 4 hyperosmotic agents?
mannitoal and urea (IV), glycerin (oral) and isosorbide (oral)
what type of receptor does the iris sphincter have?
muscarinic
what type of receptor does the iris dilator have?
alpha
what type of receptor does the ciliary body have?
muscarinic
