Lecture 4 - Mydriatics and Cyclopegics Flashcards
What is an MAO and COMT?
An enzyme of catecholamine metabolism
What is a catecholamine?
Hormones: Dopamine, EPI, NOR-EPI; produced from tyrosine in postganglionic fibers of the ANS and the Adrenal Medulla
What is an anaphylaxis?
Acute, systemic hypersensitive reaction to an allergen
What main Immunoglobulins is key in anaphylaxis?
IgE
Note: Goes into a bloodstream reacts with an antigen leading to histamine release from Mast cells
What are three issues in regards to an emergent systemic anaphylaxis?
Swelling, Bronchoconstriction and vasodilation
If you must administer an EPI pen, what pts. do you not want to administer this to?
Pts. who suffer from Heart Disease or High Blood Pressure, Parkinson’s disease (dopamine deprivation), diabetes or a thyroid disorder
What are 2 sympathetic neurotransmitters used?
EPI (generated in the adernal and sent to the blood cells) and NOR-EPI (made by nerves and thrown into the synaptic cleft)
What is the one neurotransmitter used for the parasympathetic system?
AcH
What receptor is associated with the terminal organ of postganglionic nerves in the cholinergic system?
Muscarinic
In sympathetic system, what analogs are stimulated for Presynaptic, Vascular, Respiratory, Cardiac, Hepatic, Pancreatic, Iris and Ciliary Body
Presynaptic: +α2 inhibition of signal propagation
Vascular: +α1 vasoconstriction; +β2 vasodilation*(Occurs in the skeletal system)
Respiratory: +β2 bronchodilation
Cardiac: +β1 ↑ contractility & conduction
Hepatic: +β2 glucogenolysis
Pancreatic: +β2 ↑ insulin release; +α2 ↓ insulin release
Iris: +α1 mydriasis
Ciliary body:
+β2 relaxation & ↑ aqueous production
-β2 or +α2 ↓ aqueous production
What is greater in a1?
NE > E
What is greater in a2 (inhibitory)?
E > or = NE
What is greater in B1?
E = NE
What is greater in B2?
E only.
What do catecholamines rely on for creating its back bone?
Tyrosine
Once tyrosine is reacted and creates Dopa, which then gets reacted with Ca+, what will this create?
Dopamine
Note: Dopamine can be stored and create NOR EPI
What are 2 that are important for Catecholamine metabolism?
COMT and MAO’s
What type of alpha molecules is reuptake in the pre-synaptic terminal?
a2
Note: MAo also reenters the presynaptic terminal
What muscle in the eye modulates vascular tone?
Lateral Rectus
What mechanism can cause adernegic effects that can suppress accommodation receptors?
Trabeculum and Schlemm’s canal
Starting from the best to the least system, what method do you use use for angle estimation?
Gonioscopy > Van Herick > Shadow Test
What anticholinergic agent blocks miotic response?
Tropicamide
What two anticholinergic agents have similiar backbones to one another?
Atropine and Homatropine (semisynthetic)
What Anticholinergic, can cause CNS effects, such as hyperactivity, halucinations and psychosis?
Cyclopentolate
Note: Lipophillic, thus it can readily cross the blood brain barrier much easier
What is Anti-cholinergic is a perfect longterm usage for amblyopia?
Atropine
By dilating the eye, the iris will give you pain but if someone has a corneal abrasion, what anticholinergic?
Homatropine
Which type of ametropia, are okay with dilation?
Myopes
What are the many adverse effects of anticholinergics?
ABCDs: Anorexia, Blur, Constipation & Confusion, Dryness, Sedation & Stasis of urine
Thirst, tachycardia, hypertension, ↓ glandular secretions: sweat/bronchial/saliva > heart, smooth muscle > GIT
