Antihypertensives are a class of drugs that are used to treat hypertension. Antihypertensive therapy seeks to prevent the complications of high blood pressure such as heart attack and stroke.
What’s going on guys welcome to another drug chug episode and today we’re going to talk about how beta blockers work plus some pharmacology so let’s get right into it so the way we’re gonna break down this video is first we’re gonna talk about the different types of and renew ik receptors then we’re gonna go over agonists verse antagonists then we’ll dive into beta
1 selective beta blockers the non-selective beta blockers then we’ll see who uses beta blockers and then we’ll talk about the beta blockers side effects that we see and we’ll go over a quick summary and if you guys stay to the end as always we’ll have a short quiz so to first understand how beta blockers work we need to talk about the different types of engineer
Jacque receptors and these receptors are located throughout various parts of our body and the first one we’ll talk about is our alpha one receptors and these are predominantly located in our arteries so when we have epinephrine or norepinephrine which are just hormones that are produced in our adrenal glands when we have these hormones attached to the alpha 1
Receptor it causes vasoconstriction and an increase in blood pressure now when epinephrine and norepinephrine bind to our beta 1 receptors well again we get an increase in blood pressure because it causes the heart to pump harder and faster and we also have our beta 2 receptors which are actually located on our lungs and when epinephrine and norepinephrine bind to
Our beta 2 receptors it actually relaxes and dilates our lungs so that we could breathe better so one good way to remember this guys is that epinephrine and norepinephrine they’re also known as adrenaline and whenever you have adrenaline pumping in your body let’s say you’re running away from a lion well it makes sense that it makes your blood vessels tighter and it
Makes your heart pump harder and it actually opens up your lungs so you could breathe better so that you run away from the line or whatever you’re running away from now you’re gonna need to memorize where these receptors are located so a good way to memorize this is alpha 1 receptors are located on your arteries beta 1 receptors are located on your heart because
You only have one heart and beta 2 receptors are located on your lungs because you have two lungs and i do want to note that these receptors are also located in other areas too but predominantly alpha one receptors are on the arteries in italy beta 1 receptors are in the heart and predominantly again beta 2 receptors are on your lungs so let’s quickly go over how
Agonized antagonists work so earlier we talked about how epinephrine and norepinephrine are agonists for our and generic receptors so when epinephrine attaches to our beta 1 receptor on our heart it’s going to increase our heart rate and our contractility well on the flip side we have our antagonists and in this case we have the drug atenolol and what atenolol
Does it antagonizes the beta 1 receptor so when atenolol is in our body we actually lose a contractility we actually decrease our heart rate and this is what’s known as a beta blocker because we’re blocking the beta receptor alright guys so now let’s get into the beta 1 selective beta blockers so remember beta 1 selective means that we’re targeting the heart so
The first drug that we’re talking about and this was also in the example prior was atenolol or brand-name tenormin we also have the sopra law brand-name isabetta and then we have two metoprolol we have metoprolol tartrate brand-name lopressor and metoprolol succinate or tocrawl xl now a good way to memorize which is which is that metoprolol succinate lasts so long
Because it’s the longer acting beta blocker and metoprolol tartrate is just a shorter acting version so if we look at the dosing we can actually see that metoprolol tartrate is dosed twice a day or b id and then metoprolol succinate is dosed daily or qd now if there’s one thing you guys are gonna remember from this video let it be this that all beta blockers end
In o law so we have a 10 all the sopra law metoprolol so they all end in oh law now i do want to mention a special type of beta blocker a unique one and this is gonna be a beta one selective beta blocker that actually also has vasodilation effects and it’s going to be nibble all or brand name by stalag so because it ends in o law we know that it’s gonna block the
Beta 1 receptors on our heart but what it also does is that it releases nitric oxide in our arteries which actually cause vasodilation in our arteries so if we slow down the heart and we increase our veinous capacity we actually decrease our blood pressure even further and one cool thing to note is if you look at the brand name by stahl ik by means to install ik
Kind of like systolic blood pressure means blood pressure so it has two ways to lower blood pressure so we went over the selective beta blockers so now let’s go over the ones that are non selective or non cardio selective and remember this just means that it doesn’t have a preference to beta 1 or beta 2 receptors meaning the heart where the lungs so our first non
Cardio selective beta blocker is a product called ngata law or core guard and then we also have a product called propanolol instant release or inderal then a long-acting version of propranolol called propanol la or inderal la so remember the non cardio selectively drugs block both the heart beta 1 receptors and the lung beta 2 receptors and typically we do not want
To block the beta 2 receptors in the lungs if we block the beta 2 receptors in the lungs it causes difficulty breathing now there is also some beta blocking agents that are non cardio select plus their alpha blockers so what does that mean that means they’ll block the heart they’ll block the lungs and they’ll block the arteries so we will get a complete decrease
In blood pressure because they do three things so here we have a product called carvedilol which is brand-name coreg this come in a longer-acting formulation called carvedilol cr or coreg cr and we have labetalol which is trendy and again these agents block the receptors on the heart block the receptors on the lungs and blocks the alpha receptors in our arteries so
It slows down the heart it constricts our lungs and it dilates our arteries which again decreases our blood pressure so which patients should use beta blockers well first off we know that beta blockers decreased blood pressure so it would make sense that if a patient has high blood pressure they would use a beta blocker another patient who may have angina pectoris
Which is this pain in your chest area would benefit from a beta blocker because it would relax the heart and stop the pain from occurring a patient that might have atrial fibrillation will also benefit from a beta blocker because atrial fibrillation means that the hearts atria is overactive and relaxing it would also net a benefit and patients that have had heart
Attacks can actually be on beta blockers to help with the post heart attack care and to decrease mortality in these patients now i do want to mention patients that have heart failure which means that their heart isn’t pumping out enough blood can also benefit from beta blockers but there’s only three beta blockers that can be used in heart failure patients and these
Beta blockers are going to be curved it’ll all be so prolong and metoprolol succinate the long-acting version of metoprolol only these three and one interesting indication is actually for migraine headaches and propranolol can be used as like a prophylaxis to help with any headaches so let’s go over some of the beta-blocker side-effects that our patients may run
Into so by far the first one might be hypotension which makes sense because these agents lower our blood pressure and our heart rate so they might experience lightheadedness they might be dizzy they might have orthostatic hypotension which means once they stand up quickly they might start feeling dizzy so it’d be a good idea to let them know that they should start
Standing up slowly and another side effect that is seen is being fatigued or tired but the good part is that these beta blockers eventually grow out of being fatigued and tired all the time so our next side effect would be actually bronchospasm so remember the non-selective beta blockers might actually block our beta 2 receptors which are on our lungs and we do not
Want that typically and when we block the beta 2 by accident it causes shortness of breath wheezing very difficult breathing patterns so we don’t want to give this to patients who have asthma or copd or any other breathing issues another side effect to watch out for is for our diabetic patients and beta blockers can actually block the hypoglycemic effects so it
Can actually mask if their blood sugar is too low so will stop them from trembling or sure or showing effects that they need more sugar in their blood which could be very dangerous for them now i do want to mention that there are black box warnings for beta blockers and the biggest thing to remember is you do not want to stop a beta blocker abruptly and this is on
The black box warning and the reason is is that our body gets so used to the beta blocker that once you suddenly stop taking it you’ll have that risk of a rebound tachycardia which means fast heartbeat and hypertension because your body is so used to it and all of a sudden you don’t have the beta blocker anymore that you get all these rebound effects so let’s have
A quick recap of all the drugs that we talked about so we know we have our beta one selective agents this is gonna be our tena law which is brand name tenormin the sopra law which is brand name zubaydah our metoprolol tartrate which are lopressor and our metoprolol succinate which is our top row excel remember the succinate will salt last so long that’s why it is
The long-acting metoprolol then we talked about a special agent that was beta one selective and has these a dilatory effects and this was nabilla law or brand name by stalag because it blocked our beta one receptor on our heart and it released nitric oxide in our arteries and then we talked about our non cardio selective agents so these didn’t care if it went to
Beta 1 or beta 2 and these were our natta law which is a brand name core guard or propanolol instant release which is in the role and our propranolol long-acting which is inderal la and then we talked about our non cardio selective plus alpha blocking activity and here we had three agents we had our carvedilol which is our core egg our carvedilol cr or long-acting
Corvette all which is correct cr or controlled release and then our labetalol or our tran date alright you guys made it to the end so just like i promised we’re gonna have our short quiz to see what we retained so number one which of the following beta blockers can be used in patients with heart failure is it our metoprolol heart rate or nebe val all or carvedilol or
Our tena law so question number two metoprolol is an engine erdrich receptor antagonist at which receptor is it our alpha 1 or beta 1 or beta 2 or our alpha 1 and beta 1 receptor so a question number 3 the generic name for top row xl is is it atenolol metoprolol tartrate nabilla lul metoprolol succinate question number 4 which of the following is true beta blockers
Can be started and stopped quickly there is no risk of reflex tachycardia all beta blockers can be used in heart failure patients non-selective beta blockers should not be used in patients with asthma alright thank you guys for watching guys made it to the end of the video if you can please check out some merch and support the channel we get some awesome t-shirt
Designs all the time if you haven’t already done so please subscribe and hit that like button so that we could reach out to other students that may need this help and also think about becoming a patreon supporter so that way we could pump out more quality videos faster and also the answers to the quiz are in the description below if you guys have any questions go
Ahead and comment we’ll get right to you until next time
Transcribed from video
How do Beta Blockers Work? (+ Pharmacology) By Drug Chug
