Beta blockers prevent catecholamines ( Epinephrine & Norepinephrine ) from binding to beta receptors.
Mainly , 3 types of beta receptors have been internationally identified : β1 , β2 , β3
” Beta receptors will be illustrated in other coming posts “
~ First generation of β blockers ~
Non-selective = blocks all β receptors (β1, β2 and β3)
notice the old man in the toon ↑
Mr . Propranolol needs to change his glasses ! , he can read the large β Letters but he cant get a clear vision of their numbers :blink: ” Non selective “
Hint : Propranolol was the first beta blocker ever to be introduced into therapy in 1965.
~ Second generation β blockers ~
High selectivity for β1 receptors
notice the business man in the toon ↑
Mr. Atenolol is a very hardworking man .. He focuses all the time on his One and only target 😎 ( β1 selective )
and since β1 is mainly found in the heart, drugs of 2nd generation are often referred to as :
” cardioselective beta-adrenergic blockers “
Mmmm … i think i should have drawn a heart on Mr. atenolol’s tuxedo :whistle:
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Beta blockers are used to reduce High blood pressure by lowering the cardiac output , but Propranolol is contraindicated in case of asthmatic hypertensive patients because it blindly blocks all β Receptors including β2 ( non selective ) blocking β2 receptor causes bronchospasm which can be very sever in asthmatic patients :dizzy: so , in case of hypertensive patients with asthma , the Beta blocker of choice is Atenolol ( selective to β1 only & has nothing to do with β2 )
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~ Third generation β-blockers ~
Non-selective = blocks all β receptors (β1, β2 and β3)
+
α1 blocker too
” Extra Vasodilation effect :happy: “
Back to the toon , notice the young man with a cap ↑
although Mr. carvidilol is young but he is far from the Flying Betas so he cant recognize their types ( Non selective )
You probably wonder what’s that thing in his mouth , and No it’s not a cigarette ..
Mr. Carvidilol likes to blow red cylindrical Gum .. this reminds you of something ?
.
.
.
Yes >> Blood vessels 😉
( Carvidilol blows Blood vessels > vasodilation effect )
Read more: How to remember Cardio Selective Beta Blockers
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Sources :
– RANG & DALE’s , Pharmacology
– Goodman & Gilman’s , The pharmacological Basis of Therapeutics
– Clinical pharmacology made incredibly easy
– Color Atlas of Pharmacology
Go on Darling :heart: :heart:
bgd WooooW
yaret te3mely manhag el pharma kolo keda :cheerful: :cheerful:
thank you Dina :happy:
more pharmacology posts are coming up soon isa , Just pray for me 🙂
Welcome @ anytime 😉
Thank you for your great article !
I’d like to ask , If the dose of selective B1 blocker increased ( Ex: atenolol ) , does this lead to blocking of B2 receptors ?
Mohamed: I’d like to ask , If the dose of selective B1 blocker increased ( Ex: atenolol ) , does this lead to blocking of B2 receptors ? There is no drug with absolute pure effect on one receptor , even in Normal doses selective B1 blockers aren’t 100% acting on B1 , actually they block some B2 receptors but in very few number that doesn’t cause side effects .. so it can be ignored , In Higher doses , more B2 will be blocked causing difficulty in breathing & bronchospasm but the worst would be that more B1 in… Read more »
i cant find words to thank you gor this website and the great effort you exirt …..i konw about it just now and from now i think i will not leave it ,but i ask you for some thing ….i’ll be greatfull if u provided us with thw links of the sources if they are web sitess….. thank you alot 🙂
Ok Sure , i’ll leave links for the websites i use from now on 🙂
Thank you very much 🙂