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Old 04-30-2014
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Listening Epinephrine in Open Angle Glaucoma

It seems so contradictory and i hate learning by memory.

does anyone have a logic explanation for this?
epinephrine STIMULATES B1 and B2 receptors,
and as FA says B2 PROMOTES aquous humour synthesis...
so why then is epi used for open a. glaucoma?
i know is a MUST NOT in acute angle.

if not i guess i should just commit it to memory
thanks in advanceeee hopefully someone has a better picture for this
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Old 04-30-2014
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Quote:
Originally Posted by drpisho View Post
It seems so contradictory and i hate learning by memory.

does anyone have a logic explanation for this?
epinephrine STIMULATES B1 and B2 receptors,
and as FA says B2 PROMOTES aquous humour synthesis...
so why then is epi used for open a. glaucoma?
i know is a MUST NOT in acute angle.

if not i guess i should just commit it to memory
thanks in advanceeee hopefully someone has a better picture for this
In eye there is beta receptor in ciliary muscle which acts for far vision( dilates) & alpha1 receptor in radial muscle & iris which dilates pupil(mydriasis) by sympathetics. Epinephrine acts here as a less selective alpha agonist and decreases aquous humor production through vasoconstriction of ciliary body blood vessels.

This is what i know.

Thanks.
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Old 05-06-2014
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Glaucoma is increased Intraocular pressure (IOP). It can be Open-angle or Closed-angle glaucoma.

In open-angle, there is decreased reabsorption of the aqueous humor.
Closed-angle galucoma is a genetic condition with increased IOP as a result of blockade of the canal of Schlemn.

There are B1 receptors in the ciliary body where the epithelial cells produce aqueous humor.
There are M receptors at the canal of Schlemn where the aqueous humor is drained.

Treatment plan is to use B blockers to decrease aqueous humor formation by the ciliary body and also increase drainage via the canal of Schlemn by using muscarinic agonist. I would advice that you first know that Pilocarpine and Echothiophate are cholinomimetics used. Also Timolol is used as a B blocker.

Epinephrine on the other hand works via Alpha 1, Alpha 2, Beta 1 and Beta 2 and is usually dose-dependent to produce different effects. Acting via Alpha 1 on the radial muscle, epinephrine will cause mydriasis without cyclopegia but I would select epinephrine as a drug of choice for glaucoma
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