NBEO Ocular Pharm
***If you see a drug name by itself, name the drug class, MOA, use, and ADEs
 Study
|
 Review All
|
 Quiz!
|
|
Mucous layer of the tears is ___ soluble. |
lipid and water |
|
What corneal layers are lipid soluble? Water soluble? |
Lipid = epith, endoth |
|
The ideal ocular drug should have what kind of lipid solubility, molecular size, ionization, and pH? |
high lipid solubility, small molecular size, low ionization, and as a weak base |
|
T/F - Muscarinic receptors are found in smooth muscle parasymp postganglionic synapses. |
True Nicotinic = skeletal NMJ and in both symp and parasymp preganglionic synapses |
|
T/F - Nicotinic receptors are found in both parasymp and symp preganglionic synapses |
True |
|
T/F - Postganglionic neurons are shorter in the sympathetic pathway. |
False - longer |
|
What ocular components have alpha adrenergic receptors? What are the actions? |
Iris dilator (A1) = dilation of pupil This relates to A2 adrenergic agonists (e.g. Iopidine, Alphagan) for IOP control |
|
What ocular components have beta adrenergic receptors? What are the actions? |
TM (B2) = relax TM, incr outflow Relates to B-blockers for IOP control |
|
What blood vessel serves as the direct source of aqueous? |
MACI (Maj Arterial Circle of the Iris), which comes off LPCA |
|
The NPCE allows active secretion of what molecules in order to draw water from MACI? |
Bicarb (inhibited by CAIs) and Na cross the NPCE, then water follows (thus active formation of aqueous) |
|
MOA of cholinergic agonists with the eye? Example of a drug? |
stimulate longitudinal muscle of CB, which pulls on scleral spur and thus opens up TM pores - results in incr outflow, decr IOP Main example = pilo! |
|
Three main structures that get parasymp innervation in eye? Actions? |
sphincter muscle (miosis), ciliary muscle (incr accom), lacrimal gland (incr tears) |
|
What drug is used during an LPI? |
Pilo - to pull iris taut |
|
1% pilo is used in this diagnostic test... |
to DDx CN III palsy vs sphincter tear w/ fixed, dilated pupil or pharm block CN III palsy will constrict, tear or pharm block won't |
|
0.125% pilo is used in this diagnostic test. MOA? |
Dx adie's - normal pupil won't respond, but Adie's will result in miotic pupil Ciliary ganglion has lesion, so sphincter is starved for ACh so even a little pilo will cause miosis |
|
Pilo ADEs? |
Browaches, HAs, myopic shift (these apply only to pre-presbyopes since ciliary muscle still works) Also decr vision in cataract pts (miosis exacerbates), *RDs, secondary ACG |
|
T/F - Cataract is a CI to pilo. |
True - smaller pupil can worsen visual problems related to cataract esp if opacity in visual axis |
|
What drug is used for the Tensilon Test? What Dz is involved? MOA? |
Edrophonium - for Dx MG; stimulates muscle strength |
|
T/F - Echothiophate is an irreversible acetylcholinesterase |
True |
|
Neostigmine is used to Tx... |
MG |
|
What cholinergic agonist has a fast onset and short mydriatic duration? |
Tropicamide |
|
What is the most potent ocular cholinergic agonist? |
Atropine |
|
How does Atropine decrease AC rxn? |
constrict blood vessels (stabilizing blood-aqueous barrier) in the CB, which contributes to aqueous formation |
|
Physostigmine can be used as an antidote for ___ toxicity. |
Atropine |
|
Botox falls in what drug class? MOA? |
Cholinergic antagonist; inhibits release of ACh at neuromuscular jxn thus inhibit muscular contraction |
|
Norepinephrine acts on what receptors? |
A1, A2, B1 (NOT B2, thus minimal effect on aqueous production) |
|
T/F - All of the adrenergic receptors in the anterior segment have B2 receptors |
True |
|
What percent Phenylephrine is useful for DDx Horner's? How does it work? |
1% - this is not enough to dilate normal eyes, but will give full dilation for Horner's pts |
|
Why is Phenylephrine not useful as a cycloplegic? |
It is an Alpha-1 agonist (which is in iris dilator). No effect on Beta receptors thus no cycloplegia |
|
What adrenergic agonist is useful as a Tx for reducing ptosis? |
Phenylephrine - incr sympathetic innervation to Muller's muscle, which retracts lid |
|
Your pt fails to dilate with cocaine and dilates with Paredrine (Hydroxyamphetamine). You suspect... |
No dilation on cocaine = (+)Horner's Dilation with Paredrine = preganglionic lesion so must R/O Pancoast's tumor at lung apex "Paredrine has a PreDilection to tumors" |
|
Epinephrine acts on what receptors? |
All adrenergic receptors (both Alphas and Betas) Compare vs Norepi - acts on all but B2 |
|
Naphazoline class, MOA, use, ADEs |
aka Naphcon-A (which also has antihistamine); Adrenergic agonist; used to constrict conj BVs (decr redness) ADEs = greater alpha vs beta effects so have potential to depress CNS; excessive use can also cause dilation since affects alpha (therefore iris dilator) |
|
Tetrahydrazoline class, MOA, use, ADEs |
aka Visine; Adrenergic agonist; used to constrict conj BVs (decr redness) ADEs = greater alpha vs beta effects so have potential to depress CNS; excessive use can also cause dilation since affects alpha (therefore iris dilator) |
|
Apraclonidine class, MOA, use |
aka Iopidine; A2 adrenergic agonist; decr aqueous production AND incr uveoscleral outflow; used to control IOP spikes after ocular surgery and for acute angle closure attack, not effective for chronic glaucoma *Apraclonidine for Acute |
|
What glaucoma drug class has two IOP lowering actions in one? Name these actions. |
A2 adrenergic agonists ("onidines")- decr aqueous production and incr uveoscleral outflow |
|
Brimonidine class, MOA, use, ADEs |
aka Alphagan; A2 agonist; decr aqueous production AND incr uveoscleral outflow; used for long-term glaucoma Tx (compare vs Apraclonidine/Iopidine) ADEs = follicular conjunctivitis, but Alphagan P has purite as the preservative which decr incidence of rxns |
|
Epinephrine MOA in lowering IOP? |
No longer used to lower IOP, but MOA = incr outflow (B2) decr aqueous production (A2) |
|
Contraindications for Epi? |
1) Aphakes: incr risk of CME |
|
Topical application of B-blockers can cause these ADEs... |
can be absorbed systemically, causing depression, impotence, bradycardia, bronchospasm (hence block sympathetic) |
|
T/F - There is little difference in effectiveness between 0.25% and 0.50% conc in B-blockers |
True |
|
What type of Beta receptors are predominant in the eye? Where are these receptors exactly? |
Beta-2 ("two eyes, two lungs" - this rule applies to Beta!) In TM, Ciliary muscle, NPCE |
|
Which beta blockers are cardioselective (both topical and systemic)? |
Atenolol, Betaxolol, Esmolol, Acebutol, Metoprolol "A BEAM of B1 blockers" |
|
What is the only topical cardioselective beta blocker? |
Betaxolol (Betoptic-S) |
|
Cosopt is made of... |
Timolol (B blocker) and Dorzolamide (CAI) |
|
Combigan is made of... |
Timolol (B blocker) and Brimonidine (A2 agonist) |
|
What is the difference between Alphagan and Betagan? |
Alphagan (Brimonidine) = A2 agonist |
|
This drug intentionally induces ptosis. Why would you want to do this? MOA of this drug? |
Guanethidine; to Tx lid retraction in Grave's; causes ptosis by limiting NE through increasing release at synapse then enhance reuptake - thus decr symp response, also blocks receptors to Muller's muscle. Both contribute to ptosis "Guanethidine Graves" |
|
Dapiprazole class, MOA, use |
aka Rev-Eyes; A1 antagonist; induces miosis post-dilation |
|
CAI MOA? |
Acts in CB epith (nonpig and pigmented), prevents carbonic anhydrase from combining CO2 + H20 into Bicarb Bicarb normally enters into posterior chamber and draws Na and water to follow, which incr IOP. In a nutshell: CAIs decr IOP by decr aqueous outflow |
|
CAI should not be used w/ pts who have a ___ allergy. |
Sulfa |
|
Name the topical and oral CAIs. |
Topicals = Brinzolamide (Azopt) and Dorzolamide (Trusopt) Orals = Acetazolamide (Diamox) and Methazolamide (Neptazane) |
|
ADEs of CAIs? How about Acetazolamide ADEs specifically? |
Metallic taste, tingling of hands, *metabolic acidosis, GI irritation In acetazolamide = bone marrow suppression, aplastic anemia, myopic shifts |
|
MOA of prostaglandins? |
Incr uveoscleral outflow |
|
ADEs of prostaglandins? |
iris heterochromia, incr pigmentation and growth of lashes, skin darkening around eyes |
|
MOA of topical ocular anesthetics |
block nerve conduction by stopping influx of Na ions into nerve cytoplasm; w/o Na entry, nerve cannot depolarize (thus won't send off signal) |
|
This drug is used along with local anesthetics to minimize systemic absorption |
epinephrine - BV constriction |
|
You're having trouble remembering which anesthetic is an ester, and which is an amide, and then you remember this mnemonic... |
Amides contain an "i" somewhere before the -aine. Esters do not (with the exception of dimethocaine). |
|
T/F - All topic anesthetics are amides. |
False - esters |
|
Which anesthetic class gets metabolized by the liver? |
Amides ("Lidocaine Longer Liver") |
|
Which anesthetic class is metabolized locally? |
Esters |
|
Cocaine causes vaso(dilation/constriction) |
constriction - thus enhances the effects of anesthesia on its own, without need for epinephrine |
|
Fluoress includes what anesthetic? |
Benoxinate |
|
Antihistamine MOA? |
Block cell receptors to histamine (H1 or H2) DO NOT prevent histamine release from mast cells and basophils |
|
Naphcon-A consists of... |
Naphazoline (vasoconstrictor) + Pheniramine Maleate (H1 antihistamine) |
|
Topical antihistamines are (H1/H2) blockers? |
H1 Recall that H2 is in the stomach |
|
Mast Cell stabilizer MOA |
acts on exposed mast cells and inhibits degranulation upon re-exposure to antigen |
|
Mast Cell stabilizers are not effective for (acute/chronic) allergic Sx |
not effective for acute since mast cells already degranulated |
|
Cromolyn Sodium class, use |
Mast cell stabilizer, used for chronic allergic conjunctivitis, vernal conjunctivitis, atopic keratoconjunctivitis |
|
Alocril and Alomide are what class drug? |
Mast cell stabilizers Also Alamast |
|
Patanol consists of... |
H1 receptor blocker and mast cell stabilizer |
|
VKC is almost always associated with... |
atopy (asthma, eczema, seasonal allergic rhinitis) |
|
VKC vs AKC? |
VKC = kids, less involved w/ outer lid & periorbital skin, *Trantas Dots (limbal papillae), *cobblestone papillae), seasonal, stringy discharge AKC = young adults, *scaly thickened swollen ITCHY lids, all year long |
|
Corticosteroid MOA |
binds to receptors on target cells - steroid/receptor complex enters nucleus and makes new mRNA Inhibits phospholipase A2, an enzyme that is in the arachidonic acid pathway; the latter pathway leads to inflammatory agents incl leukotrienes and prostaglandins |
|
Corticosteroids (incr/decr) capillary permeability? |
decr |
|
Critical corticosteroid ADEs? |
Incr risk of secondary infections (HSV!), PSCs, glaucoma (incr IOP) |
|
NSAID MOA? |
Blocks COX, thus stop conversion of arachidonic acid into prostaglandins and thromboxanes |
|
Diclofenac Sodium class, use |
aka Voltaren; ocular NSAID; for post-op inflammation/prevent CME and Tx allergic conjunctivitis |
|
Ketorolac Tromethamine class, use |
aka Acular; ocular NSAID; for post-op inflammation/prevent CME and Tx allergic conjunctivitis |
|
Trifluridine MOA |
inhibits replication of viruses by producing faulty viral DNA |
|
Antimetabolites are used in ophthalmic practice mostly for ___. Name two. |
trabeculectomy; 5-fluorouracil, Mitomycin C |
|
Rose bengal stains... |
healthy epith cells that are not covered by mucous (does not enter epith defects like NaFl or Lissamine Green) |
|
Lissamine green stains... |
epith cells unprotected by mucous AND epith defects vs Rose Bengal - does not stain epith defects |
|
IV Fluoroscein Dye takes ___ secs for it to show up in choroidal and retinal vessels. |
10-20 |
|
What drug class is the best to decr IOP? MOA? |
Hyperosmotic agents (draws gradient towards blood to decr outflow) ex = Isosorbide, Glycerine |
|
Isosorbide class, MOA, use, ADEs |
Hyperosmotic agent; huge molecular weight compounds that draw water back into blood vessels from posterior chamber thus decr IOP; for acute angle closure attack ADEs = vomiting if not sipped Mixed with soft drink over crushed ice |
|
Glycerine class, MOA, use, ADEs |
Hyperosmotic agent; huge molecular weight compounds that draw water back into blood vessels from posterior chamber thus decr IOP; for acute angle closure attack ADEs = vomiting if not sipped, NOT for DM b/c incr BG Mixed with soft drink over crushed ice |
|
Which has more ocular contact time - methylcellulose or polyvinyl alcohol? Why? |
methylcellulose b/c more viscous |
|
Benzalkonium chloride MOA, use, ADEs |
aka BAK; ruptures bacterial cell memb; used as preservative ADEs = epithelial toxicity with prolonged use |
|
Viroptic uses this preservative... |
Thimerosal hence prolonged use not recommended |
|
Chlorhexidine use... |
preservative in Boston Simplicity and other RGP cleaners |
|
What causes whorl keratopathy? Although rare, this drug also causes this other ADE? |
Amiodarone; also causes optic neuritis |
|
T/F - Antianxiety agents tend to cause dry eyes |
True |
|
T/F - Antihistamines tend to cause dry eyes |
True |
|
Ritalin causes (miosis/mydriasis)? |
mydriasis |
|
Antihistamines cause (miosis/mydriasis)? |
mydriasis |
|
Amphetamines cause (miosis/mydriasis)? |
mydriasis |
|
Heroin causes (miosis/mydriasis)? |
miosis (opiate drug causes pinpoint pupils e.g Morphine, Codeine) |
|
Digitalis ocular ADEs... |
B/Y color defect, pain on eye movement |
|
Ethambutol toxicity to eye... |
optic neuritis |
|
Isoniazid toxicity to eye... |
optic neuritis |
|
Chloramphenicol toxicity to eye... |
optic neuritis |
|
Crystalline retinopathy is caused by toxicity from this drug... |
Tamoxifen |
|
These drugs cause RPE and outer retinal degeneration, pigment deposits throughout eye, and cataracts. What is this drug class? |
Phenothiazines (Chlorpromazine, Thioridazine) |
|
Canthaxanthin ocular toxicity? |
crystalline retinopathy, color blindness |
|
Oral contraceptive ocular toxicity? |
optic neuritis, papilledema, pseudotumor cerebri, dry eyes |
|
T/F - A drug with a aigher therapeutic index is safer |
True TI = LD50 / ED50 |
|
Therapeutic Index = |
LD50 / ED 50 Lethal Dose that kills 50% of experimented animals |
