PHARM I: EXAM #1 (OPHTHO LEC)

absorption pattern of topical optic drugs?

usually fast

best bioavailability is related to what property of the solution?

viscosity - gels, ointments, and solid inserts have higher absorption

antimalarials like chloroquine causes what in the retina?

bulls eye lesion in the retina

what does dipivefin get converted to into the eye?

epinephrine

what does latanoprost get converted to into the eye?

prostaglandin F2a

Limitations to eye medications?

- limited systemic bioavailability (which is good)
- high local concentrations (also good)
- need for frequent dosing (decr in compliance)

what macrolides are available as optic suspension?

- erithromycin
- azithromycin (Azasite)

MOA for macrolides

inhibits protein synthesis

side effects of macrolide optic suspension?

...........

different forms of macrolide administration for eyes?

- erythro comes as a gel
- azithro comes as solution

Why would we prescribe erythromycin for something that is not bacterial?

erythromycin is soothing for an inflamed eye, so it is ok to prescribe for a viral conjunctivitis
* such a high concentration that we do not need to worry about resistance

MOA for trimethoprim/Polymyxin B (Polytrim) solution

trimethoprim - folic acid inhibitor (protein syntheiss inhibitor)
polymyxin B - cell membrane inhibitor

adverse effects of all optic medications?

ocular irritation

sulfacetamide (ointment/solution) MOA?

folic acid inhibitor/protein synthesis inhibitor

adverse reaction to sulfacetamide?

allergic reactions - dont give to people with Bactrim allergy

bacitracin MOA?

inhibits cell wall synthesis

Fluoroquinaline optic agents include

cipro
ofloxa
levo
moxi
gati

Side effects of FQs?

bad taste
white precipitate may form with cipro

MOA for optic FQs?

DNA inhibitor

aminoglycoside MOA

inhibit protein synthesis

adverse reactions to aminoglycoside optic solutions?

corneal ulceration
reactive keratoconjunctivitis with prolonged use

trifluridine (Viroptic) MOA

inibibits thymidylate synthetase and takes the place of DNA

adverse effects to trifluridine?

punctate keratopathy

gancyclovir MOA

inhibits binding of deoxyguanosine to DNA polymerase

gancyclovir adverse reactions

punctate keratitis

the only antifungal commercially available is called

natamycin

natamycin MOA

cell wall inhibitor

how do cell wall inhibitors work?

increase permeability to cause cell structure to break down

how to properly administer ophthalmic medications?

1. wash hands
2. don't touch the dropper
3. tilt head back and pull down the lower eyelid to form a pocket
4. dont touch the dropper to the eye
5. place drops
6. close eyes and hold finger over lacrimal duct
7. wait 2-3 minutes

Patient education for using optic ointments

will blur vision for about 20 minutes

How do H1 receptor inverse agonists work?

Inactive histamine receptors, but is still competitive with histamine.

actions of H1 receptor antagonists?

- decrease capillary dilation
- decrease itching
- decrease swelling

available optic antihistamines

azelastine
alcaftadine
bepotastine
emedastine
epinastine
ketotifen
olopatadine

adverse effects of H1 receptor antagonist optic solution

HA, increased ocular dryness

Mast cell stabilizers MOA

- inhibits mast cell degranulation - inhibits release of histamine
- decreases inflammatory chemicals from other inflammatory cells

side effects of mast cell stabilizers?

HA, unpleasant taste

available vasoconstrictor/antihistamine optic agents

tetrahydrozoline
naphazoline
pheniramine

vasoconstrictor/antihistamine caution

not for prolonged use - susceptible to rebound effect

What receptors does imidazoline derivatives target?

alpha 1 receptors locally - vasoconstriction
alpha 2 receptors systemically - vasodilation

NSAID MOA?

- block action of cyclooxygenase (COX) AND
- inhibits conversion to prostaglandin and thromboxane

Optic NSAID agents

bromfenac
diclofenac
flurbiprofen
ketorolac
nepafenac

adverse reactions to optic NSAIDs?

- tearing
- keratitis
- IOP increase

gluccocorticoids MOA

- reduce arachidonic acid derived pro-inflammmatory mediators
- inihibts fibrin and collagen deposition - decrease scar formation

adverse effects of gluccocorticoid optic solutions

- cataract
- elevated IOP
- increased risk for infection
- delayed wound healing
- corneal ulcers

how long can you be on ocular gluccocorticoids?

no more than 2 weeks

diseases that may cause dry eyes

- Sjrogen's syndrome
- rheumatoid arthritis
- Vitamin A deficiency
- SJS

what kind of ingredients are in artifical tears?

electrolytes
surfactants
liquid thickeners

Medical therapy for dry eyes

- hypotonic/isotonic solutions with electrolytes, surfactants, thickeners
- balanced salt solution (BSS)
- carboxymethyl cellulose (Refresh)
- hydroxypropyl cellulose (Lacrisert)
- polyvinyl alcohol (artificial tears)

what type of drug is cyclosporine (restasis)?

immunomodulator for keratoconjunctivitis sicca

MOA for restasis?

less T cell activation to decrease inflammation and increase tears

Restasis side effects

ocular burning, foreign body sensation, blurred vision

normal IOP

10-21 mmHg

Agents that increase acquous outflow?

1. prostaglandins - 1st line
2. alpha adrenergic agonist
3. cholinergic agents

agents that decrease aqueous production

- alpha adrenergic agonists
- BB
- carbonic anhydrase inhibitors

Available prostaglandins (have -prost)

latanoprost
travoprost
bimatoprost
tafluprost

adverse reactions to optic prostaglandins?

- conjunctival hyperemia
- changes in eyelash length
- iris changes to brown

BB MOA for glaucoma

less catecholamine activation --> decreased cAMP --> less acqueous humor produced

Beta 1 selective blockers

betaxolol

Non-selective beta blockers for eyes

carteolol
timolol
levobunolol

beta blocker side effects

- worsening heart failure
- bradycardia, heart block
- increased airway resistance (asthma)

difference between using a selective and non-selective beta blocker

selective only activates B1 so less risk for an asthma attach (bronchoconstriction)

pros and cons of using nonselective BB?

more effective, but more side effects
**don't use a beta blocker on asthmatics

alpha 2 agonist MOA in eye

- decreased catecholamine release --> less aqueous production
- alpha 2 activation --> further decrease in aqueous production

avialable alpha adrenergic agents for eyes?

apraclonidine
brimonidine - more lipophilic (bad absorption)

-nidine

side effects of alpha 2 agonists

hyperemia (rebound effect)
pruritus
allergic conjunctivitis (less common with brimonidine)

Carbonic Anhydrase Inhibitor MOA

inhibits carbonic anhydrase in ciliary body epithelium to decrease production of bicarbonate ions to decrease fluid transport and IOP

available carbonic anhydrase agents for eyes

dorzolamide
brinzolamide

cholinergic agonist MOA

contracts ciliary muscles to increase outflow

available cholinergic agonists for eyes

- Ach
- carbachol
- pilocarpine

adverse reaction of cholinergic agonist for eyes

- chronic miosis
- vision changes

combo eye drugs for glaucoma

brimonidine + timolol = Combigan
brinzolamide + brimonidine = Simbrinza
dorzolamide + timolol = Cosopt

ocular anesthetics MOA

inhibit sodium influx into neuron preventing depolarization

available agents for ocular anesthetics

tetracaine
preparacaine

adverse reactions for ocular anesthetics

hypersensitivity
burning sensation
no blink response

MOA for cycloplegic agents

block muscarinic ACh receptors

OR

adrenergic receptor agonist

adverse reactions to antimuscarinic agents

photosensitive and blurred vision due to inability to focus on objects

think about when you go to the doctor, get your eyes dialted, and they give you glasses.

what do sympathemimetics do in the eye?

mydriasis

side effects of sympathomimetic agents in the eye

photosensitivity and conjunctival hyperemia

What is Trypan Blue used to visualize?

visualizes the lens

what is fluoroscein used to see visualize

cornea and conjunctiva