Sympathetic System Ocular Drugs - 10/3

What does the "P" stand for in Alphagan-P ? Is this drug still around today?

"P" stands for purite which was the preservative used in the drug when originally came out to market in 1996 after patent expired was brought to market wout the purite preservative and has been reformulated a few times

10% phenylephrine should avoid being used in which two patient populations? Phenyl in general should be avoided in what other populations?

10% avoided in neonates / elderly h/ myocardial infarctions, uncontrolled diabetes (esp TI), ateriosclerosis, etc

______% phenylephrine can be used for pre-LASIK vasoconstriction to prevent bleeding during sx ____ % phenyelphrine can be use to evaluate for Horner's

10% phenyl for pre-LASIK vasoconstriction 1% for Horner's eval

What are the two prominent concentrations Phenylephrine dilating gtt come in?

2.5% 10%

Phenylephrine mildly suppresses one's accommodation by about _______ diopters and causes ________ via Mueller's stimulation

2D LID RETRACTION

In general some adverse effects of sympathomimetic drugs on the central nervous system are ________ , fear, headaches, or the potential for ________ strokes

ANXIETY / fear potential for hemorrhagic strokes

_______ is an alpha2 adrenergic agonist drug originally approved for glaucoma treatment as "Alphagan-P" in 1996

Brimonidine

What are the 3 major mechanisms of sympathetic vasodilation? What about vasoconstriction? (name the structural mechanism and receptors present)

DILAITON: Endothelial cell receptors - alpha1/2/3 Smooth muscle cell receptors - beta Nerve cell terminal receptors - alpha2 / beta CONSTRICTION smooth muscle cell receptors - alpha1/2

T/F: Phenylephrine can cause a range of adverse side-effects such as photophobia, rebound miosis and congestion, allergic reactions, and systemic hypertension w tachycardia

FALSE --> causes BRADYCARDIA w systemic hypertension (heart slows down in response to increased bp when phenyl gets into circulation)

_______ is an indirect-acting sympathomimetic agent that promotes NE release from nerve terminals and reduces reuptake, causing contraction of the iris radial muscles and a mydriatic response

Hydroxyamphetamine **also has negligible direct recetpro activation of alpha/beta receptors

In general, some adverse effects of sympathomimetic drugs on the cardiac system are _______ heart rate, arrhythmias, and _______ blood pressure

INCREASE heart rate ELEVATED bp

__________ are the name of a class of adrenergic agonistic drugs (gtt) which have an enhanced selectivity for alpha-1 receptors of the eye ; what is one disadvantage of using this drug type?

Imidazolines **exhibit tachyphylaxis (dec. response to a drug after repetitive administration)

Does the 1% hydroxyamphetamine formulation cause any accommodative suppression for the patients?

NO

Can anticholinergic agents be used for sectoral dilations?

NO bc relaxes sphincter 360-degrees so need sympathomimetic Phenyelphrine for this job bc contracts only portion of iris dilator! **cannot use tropic or Paremyd for this then

_______ is an example of a sympathomimetic Imidazoline eye drop that works by acting as an alpha-2 adrenergic agonist

Naphazoline EX: Clear Eyes reduces output of sympathetic nervous system by inhibiitng release of sympathomimetics on ocular structures **is not 100% selective

Give 3 examples of imidazoline OTC gtt used to treat red-eye

Naphazoline EX: Clear Eyes 0.012 or 0.02% Tetrahydrozoline EX: Visine 0.05% Oxymetazoline

Which adrenergic agonist compound was originally used as the active ingredient in visine and then was d/c and eventually re-used by Upneeq? Why? What does Upneeq gtt do?

Oxymetazoline now used in Upneeq @ 0.1% (vs 0.025% in Visine LR) as first FDA approved drug for blepharoptosis as it is an adrenergic agonist which stimulates interpalpebral size to increase due to stimulation of Muller's muscle

_________ is an example of a sympathomimetic Imidazoline eye gtt that works as an alpha-1 agonist and an alpha-2 partial adrenergic agonist

Oxymetazoline EX: Visine LR 0.025% that was d/c in 2015

What are the two main sympathomimetic amine drugs used for ocular dilation ?

Phenylephrine **direct Hydroxyamphetamine (in Pyramed) **indirect-acting

_________ drugs are those that are antagonistic to the sympathetic nervous system

Sympatholytic drugs

T/F: Both phenylephrine and hydroxyamphetamine gtt can be used in the diagnostic process when detecting Horner's Syndrome

TRUE!

________ is an example of a sympathomimetic Imidazoline eye gtt that works by acting as an alpha-1 adrenergic agonist

Tetrahydrozoline EX: visine 0.05%

Does IOP reduction occur when using phenyelphrine gtt? Why or why not?

Yes but MINIMALLY bc phenyl is mostly an alpha1 selective agent but in case that binds alpha2 receptors is can decrease IOP / aq production

Why is Lumify's formulation as an adrenergic agonist so unique compared to the other "redness relieving" drugs out on the market such as Visin

bc Lumify uses low concentration of brimonidine which is an alpha2 agonist ==> causes constriction of ocular VENULES so reduces redness while still allowing O2 to reach ocular surface ; meanwhile drugs like Visine work as alpha1 agonists which constrict ARTERIOLES and thus also deprive the eye of O2 / nutrients necessary for proper maintenance

Why is phenylephrine never used along as a dilating drop?

bc its mydriatic response takes about 45-60 minutes and thus it is always combine w an anticholinergic for faster / greater dilation

Why should you check the AC for cells and flare BEFORE putting any dilating drops (such as phenyl) in one's eyes?

bc phenyl can cause anterior chamber pigment liberation and this may be confused w "cells & flare" if not previously documented before putting drops in!!

_______ receptor stimulation occurs when much higher doses of Phenylephrine are used which then causes the eyes to get red

beta receptor stimulation occurs @ much higher doses of PE (normal doses use alpha-1 receptor selectivity) ==> vasodilation and redness of eyes

Phenylephrine induces conjunctival ________ and can thus be used to distinguish episcleritis from scleritis cases

conjunctival BLANCHING (vasoconstriction) - alpha1 mechanism **if episcleritis, will see constriction when using this gtt... if scleritis, will not see constriction w this gtt

What is Pyramed?

dilating drop containing 1% hydroxyamphetamine (indirect acting sympathomimetic amine) and 0.25% tropicamide (parasympatholytic)

What is one adverse effect of sympathomimetic drugs on the hepatic system? What about the immune system? Respiratory system?

hepatic- elevated blood sugar immune - immunosuppression respiratory - pulmonary edema

What is the most recent reformulation of the original "alphagan-P" drops and how is this reformulation used today?

most recent ==> brimonidine sln is reformulated in 2018 as LUMIFY w brimonidine being at 0.025% instead of 0.1/0.15% Lumify is used to reduce ocular surface redness today

In general, some of the adverse ocular sympathomimetic drug responses include photophobia, _______ of accommodation, and _______ depth of focus

suppression of accommodation / near blur decreased depth of focus

Phenylephrine has synergistic effects with what 3 other drug classifications? What antagonistic effects does it have w 2 other drug classifications?

synergistic: - monoamine oxidase inhibitors (MAOIs) - tricyclic antidepressants (TCADs) - atropine antagonistic: - methyldopa (anti-hypertensive) - beta blockers

Briefly describe why phenyephrine is a useful adjunct dilating agent in older patients; is this drop needed for younger patients too?

with age the sympathetic tone of our muscles decrease causing age-related miosis thus, a simple parasympathetic paralytic drop (anticholinergic agent) alone does not provide enough dilation for a proper fundus exam so sympathomimetic drug phenyelphrine (2.5%) is used to heighten dilation by stimulating greater sympathetic response of dilator muscle this is NOT always needed w younger patients who have greater sympathetic tone and can just dilate w anticholinergic agent