Beta 2 blocker

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In a qbank i'm doing it says that the antidote for Beta blocker overdose is glucagon. Isnt this wrong????

Beta 2 release insulin, so if you block this, you have a higher blood sugar. Then if you give glucagon, wouldnt that make the blood sugar higher???

So i dont think you should give glucagon for beta blocker overdose. Am I correct or wrong??

The answer is right.

http://www.usmleforum.com/archives/2006/1/75499.php

I am sure you can look up more PubMed articles to further delineate the mechanism.

Glucagon activates adenylyl cyclase in order to contract the heart to override the B2-blockade on cardiac contractility.

Something like that anyway..

Originally Posted by Dr McSexy

Glucagon activates adenylyl cyclase in order to contract the heart to override the B2-blockade on cardiac contractility.

Something like that anyway..

thanks!!!!!!!!! that was tricky

Also, b2 receptors stimulate gluconeogenesis. ODing on b-blockers could theoretically make you hypoglycemic, which can be fixed with glucagon. Just another MOA for you

I didn't even know there were glucagon receptors on the heart haha, glad I read this thread. I wonder why though...

Also b-blockade causes b receptor up regulation, so if you give a beta agonist, you risk overstimulation.

Originally Posted by Aclamity

Also, b2 receptors stimulate gluconeogenesis. ODing on b-blockers could theoretically make you hypoglycemic, which can be fixed with glucagon. Just another MOA for you

I didn't even know there were glucagon receptors on the heart haha, glad I read this thread. I wonder why though...

hmmm that is weird.. so beta 2 increases insulin secretion from pancreas and also stimulates glycogenolysis and you get glucose. Does't that cancel each other out?

Originally Posted by StressedMedStud

hmmm that is weird.. so beta 2 increases insulin secretion from pancreas and also stimulates glycogenolysis and you get glucose. Does't that cancel each other out?

I believe that the insulin is required to absorb the glucose that is produced during the glycogenolysis. This is why glucagon needs insulin, but not the other way around. So it's more of a synergistic thing, not necessarily canceling each other out.

Originally Posted by GTP

I believe that the insulin is required to absorb the glucose that is produced during the glycogenolysis. This is why glucagon needs insulin, but not the other way around. So it's more of a synergistic thing, not necessarily canceling each other out.

Yea, this. What's the use of stimulating gluconeogenesis if you have no insulin to utilize the glucose? b2 stimulates just enough insulin so that the muscles and other tissue can take it up. Thsi is all from Raymon