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beta blocker\glucagon

4K views 4 replies 3 participants last post by  gofish6060 
#1 ·
This maybe a stupid question but what is the mechanism for glucagon being a antidote for beta blockers? Bc if the beta 2 receptor is blocked it would decrease insulin release bc if it were activated it would increase insulin release..... just trying to figure it out, thanks
 
#2 ·
Glucagon (^cAMP) which reverses BB-mediated decrease of cAMP. which is why its an antidote.

Blocking B2 receptors with Propanolol for example, leaves A2 working and this is what decreases Insulin secretion.

Using an Agonist at B2 receptor like Ritodrine could increase insulin release.

hope that makes sense.
 
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#3 ·
Thank you, so if u were to give a alpha blocker say phentolamine with a beta 2 blocker you would not have a change in blood sugar? But if u gave glucagon in this case it would increase the blood sugar while treating the over dose from the beta blocker bc the alpha 2 is blocked? Also why do beta blockers help with panic attacks?

Thanks
 
#4 ·
Thank you, so if u were to give a alpha blocker say phentolamine with a beta 2 blocker you would not have a change in blood sugar? But if u gave glucagon in this case it would increase the blood sugar while treating the over dose from the beta blocker bc the alpha 2 is blocked? Also why do beta blockers help with panic attacks?

Thanks
let me explain it this way.
Say you give High dose EPI - this stimulates A2 receptors which decease insulin secretion.
Now what if you pre-treat with Phentolamine as you suggest, and then re-administer high does Epi. This will increase insulin secretion because phentolamine is blocking the Alpha response but leaving the Beta 2 response and this is what is increase insulin.

if you blocking both alpha and beta theoretically you're blocking the stimulation and inhibition of insulin secretion.

beta blockers would decrease catecholamine surge in anxiety which is good. generally treated with SSRI, TCA and Benzos but can be used for Performance anxiety
 
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