Ocular Pharmacology Flashcards
Where is dilator smooth muscle and how is it orientated?
anterior to the pigmented epithelium and is oriented radially
Where in the pupil constrictor (sphincter) smooth muscle and how is it orientated?
pupillary margin and is organized in a circular band
What nervous system causes pupil dilation? Via what receptor?
Sympathetic
Alpha-1
What other effects does the sympathetic nervous system have on the eye? Via what receptors?
Aqueous humor production (alpha-2/beta-2) Lacrimal secretions (alpha-1)
What nervous system causes pupil constriction? Via what receptor?
Parasympathetic
M3
What other effects does the parasympathetic nervous system have on the eye? Via what receptors?
lacrimal secretions (M2/M3)
Where are the three places where ocular (topical) drugs can have systemic effects?
- Cheeks
- GI tract (post lacrimal drainage)
- General circulation (via ocular blood vessels)
True or false: the eye contains metabolic enzymes.
TRUE (ex. esterases, peptiases, MOA, etc.)
What is the role of the metabolic enzymes contained within the eye during drug therapy?
can convert more penetrative pro-drugs to their active form once they have entered the eye (improved therapy and diminished toxicity)
List the muscarinic antagonists used on the eye.
CHATS Cyclopentolate Homotropine Atropine Tropicamide Scopolamine
List the muscarinic agonists used in the eye.
Carbachol
Pilocarpine
Aceylcholine HCl
List the AchE inhibitor used in the eye.
Echothiopate
List the sympathomimetics used in the eye
Dipivefrin Phenylephrine Apraclonidine Brimonidine Naphazoline Tetrahydrozoline
List the PG analogs used in the eye.
Latanoprost
Travoprost
Bimatoprost
List the beta-adrenergic antagonists used in the eye.
Timolol Maleate
Levobunolol
Metipranolol
Carteolol
List the carbonic anhydrase inhibitors used in the eye.
Dorzolamide
Brinzolamide
What drug class is used for:
Dilation of eye (mydriasis) for exam
Treatment of isis/uveal tract inflammation?
Muscarinic antagonists
What drug class is used for: Constriction (miosis); Glaucoma?
Muscarinic agonists
What are AchE inhibitors used for?
glaucoma
Sympatheticomimetic used in glaucoma only?
dipivefrin
Sympatheticomimetic used for Mydriasis, decongestant, vasoconstriction?
phenylephrine
Sympatheticomimetic used in glaucoma AND ocular HTN?
Brimonidine
Sympatheticomimetic used in ocular HTN only?
apraclonidine
Sympatheticomimetics used as decongestants only?
naphazoline
tetrahydrozoline
What drug class is first line treatment for glaucoma?
PG analogs
What drug classes are used as alternative or adjunctive to PG analog for glaucoma?
Beta-adrenergic antagonists
Carbonic Anhydrase Inhibitors
MOA: Block M receptors in cornea, lacrimal glands, and iris sphincter and ciliary muscles
Muscarinic antagonists
Muscarinic antagonists found in Angel’s Trumpets?
atropine
scopolamine
MOA: Constrict the pupil to encourage flow of aqueous humor and improve glaucoma.
Muscarinic agonists
AchE inhibitor
MOA: epinephrine pro drug.
dipivefrin
MOA: alpha-2 stimulation which leads to decreased IOP by increasing outflow of aqueous humor
apraclonidine
brimonidine
MOA: alpha stimulation which leads to decreased IOP by increasing outflow of aqueous humor
Phenylephrine
Naphazoline
Tetrahydrozoline
MOA: Possibly facilitate aqueous outflow via accessory uveoscleral outflow pathway
PG analogs:
Latanoprost
Travoprost
Bimatoprost
What is interesting about the pharmacokinetics of PG analogs?
Prodrug→ in situ hydrolysis
MOA: Block ciliary body and blood vessel β2 receptors to decrease aqueous humor production (cAMP-PKA stimulation) OR decrease ocular blood flow and ultrafiltration that produces the humor.
beta-adrenergic antagonists: TImolol Maleate Levobunolol Metipranolol Carteolol
MOA: Blockage of catalyzes conversion of CO2 to HCO3- (by Zn containing metalloprotein= CA2) whih reduces fluid transport and decreases IOP
carbonic anhydrase inhibitors:
Dorzolamide
Brinzolamide
Muscarinic antagonists are contraindicated in what conditions?
glaucoma
sulfite allergy
List some local toxicities of muscarinic antagonists.
Myadriasis, cytoplegia and photophobia; Increases ICP, stings/burns
List some systemic toxicities of muscarinic antagonists.
dry mouth, tachy-cardia, palpitations, somnolence, patients iwth increased risk of retinal detachment
Muscarinic agonists should be used with caution in what conditions?
CV failure, asthma, peptic ulcer
Muscarinic agnoists are contraindicated in what conditions?
iritis, uveitis, inflammation of anterior chamber
Why do young patients tend to stop taking muscarinic agonists as prescribed?
visual blurring (myopia)
Echothiopate can cause cataracts in what patients?
’phakic patients”
Which is more toxic, a muscarinic agonist or an AchE inhibitor?
AchE inhibitor
Echothiopate is contraindicated in what condition?
Closed-Angle Glaucoma due to ICP
Echotiopate should NOT be taken with what drugs?
carbamate/ phosphate insecticides
What drug class causes photosensitivity, conjunctival hyperemia, hypersensitivity but has RARE systemic effects?
Sympathomimetics
Sympathomimetics should be used with caution in what conditions?
HTN, hyperthyroidism, diabetes, arteriosclerosis, and asthma
What are the acute toxicities of PG analogs?
blurred vision, burning, stinging, itching of eyes
What is the strange systemic toxicity of PG analogs?
Lengthens and thickens eyelashes (hypotrichosis), permanent brown pigmentation of iris/eyelids
What drug class is co-formulated with preservatives (benzalkonium chloride) that can damage soft contact lenses?
Beta-adrenergic antagonists
What drug class is known for historical bacterial contamination?
carbonic anhydrase inhibitors
What is a systemic adverse effect of carbonic anhydrase inhibitors?
dysgeusia (bitter taste from inhibiting CA2 in mouth)
In what condition are carbonic anhydrase inhibitors contraindicated?
sulfa allergy
What is the average IOP?
10-21 mm Hg
What is the condition in which drainage of the aqueous humor is impaired, the pressure within the eye increases, compression of the retina occurs and damage the optic nerve results?
glaucoma
What are the goals for treatment of open angle glaucoma?
decrease aqueous humor production and/or increase aqueous outflow
What is the treatment for closed angle glaucoma?
surgical iridectomy; short-term medical management to decrease IOP and clear cornea before surgery
Name the IV VEGF decoy receptor.
Aflibercept
Name the IV VEGF antagonist.
Pegaptanib
Name the IV VEGF mAb’s.
Ranibizumab
Bevacizumab
Name the IV non-thermal laster activator that generates free radicals.
verteporfin
How does verteporfin work?
Free radicals lead to vessel damage and subsequent platelet activation, thromosis, and occlusion of the choroidal neovascularization
What are the risks of VEGF mAbs, antagonists, and decoy receptors?
Arterial thromboembolic events like TE, nonfatal stroke, nonfatal MI, or vascular death
What do you advise patients of who get verteporfin for their macular degeneration treatment?
they will get temporary photosensitization (avoid direct sun for 5 days)
How do opioids cause pinpoint pupils?
depressant effect on an inhibitory neuron (which then allows unregulated and spontaneous cholinergic stimulation from pupilloconstrictor neurons in the E-W nucleus) and is affected very minimally by the peripheral sympathetic dilator muscle.
