Beta blockers. See, we got a football player up there, right? -alol, -olol, -olols.
These are beta-adrenergic blockers. Just another way of saying beta blocker.
Beta receptors are in the adrenergic receptor family
so that's why we call it beta-adrenergic blocker or beta blockers.
So they prevent this direct stimulation of the sympathetic nervous system through those receptors.
They block those receptors so the catecholamines like norepinephrine and epinephrine,
they can't hit those beta receptors and bind to them.
So antagonist, that's what they do.
They're drugs that will fit those receptors but nothing happens.
So when a beta blocker hits a beta receptor,
that beta receptor can't be activated because their dance card is full.
That drug is on the receptor so when norepinephrine and epinephrine are coming around,
they can't bind to the receptors and cause that sympathetic nervous system response.
Now, we've got beta 2 receptor sites: the bronchi, the blood vessels, and the uterus
which is usually not why we're using them.
But beta 1 receptor sites are on the heart. I usually remember one heart, beta 1.
Two lungs, beta 2.
Now, they're on some other places but that's a simple way to remember the location of those.
So when you take a beta blocker, they'll be hitting those receptors.
So non-selective beta blockers will block both beta 1 on my heart and beta 2.
Examples of those, labetalol, propanolol.
Selective beta blockers primarily hit the beta 1 receptors.
So like atenolol, bisoprolol, esmelol. But here's the deal.
Certain patients even on a selective one, the beta 2 receptors are also blocked.
So we can use it for angina. Hey, that makes sense.
Less workload on the heart requires less oxygen, less chest pain.
Same thing after an MI. Less workload, that's good.
High blood pressure, how does that help?
Less sympathetic nervous system stimulation.
The heart is not pumping as hard and as fast so that's really helpful.
We can use it in cardiomyopathy. It's gonna minimize the workload on the heart.
Also with supraventricular arrhythmias because it hits those receptors right on the heart.
Anxiety, whoa, I thought you said this was hypertension?
Remember, anxiety is a sympathetic nervous system response, right?
I'm just really jazzed. This will help deal with anxiety.
In fact, this is my favorite drug group to recommend for students that have true exam anxiety.
You know, the kind where you see the paper or you see the computer screen and your mind just freezes.
Yeah, this will help you with that.
That heart racing and that response, beta blockers taken just on test day can be a really good option.
It doesn't make you sleepy but stops that palpating heart that goes along with it.
So if that's an issue for you, talk to your health care provider. You can start on a low dose.
Practice with it before exam day and see how you're affected and it's usually a really good alternative.
Now, we can use it for tremors, headaches, open-angle glaucoma, and pheochromocytoma.
You're not gonna be able to remember all those.
If I had to pick which ones are most important, I would go with hypertension and angina and chest pain.
Those are the ones I would look at. Things that I'm decreasing the cardiac workload.
However, these others are interesting and anxiety
will probably make sense for you especially since I talked about exam anxiety.
Now, some of the problems with beta blockers.
Now, we talked about they can be cardio-selective or they can go on both, the beta 1s and the beta 2s,
but remember how I mentioned that they can sometimes even if they're supposed to just hit the beta 1s,
on certain patients, they can also knock out the beta 2s.
So beta 2's job is to bronchodilate.
So you wanna educate every patient why you're taking the beta blockers.
If you notice becoming short of breath and feeling like you can't catch your breath,
that could be a bronchospasm.
So you want them to know breathing problems, beta blockers, bad news.
You need to let us know and we'll help you work through it
but you need to know as a health care provider that any patient on a beta blocker
is at risk for a bronchospasm because their lungs need to bronchodilate.
That response may be blocked because the medication is on the receptors in the lungs.
So it will block that bronchodilation. Now, you see hypotension listed there.
Anything a drug does well, it can do over well.
Anything you take by mouth seems like you can upset your stomach.
That's the reason for nausea and vomiting.
Here's the real drawback why it's difficult for male patients to be compliant with this medication.
Because it can cause impotence is some patients.
You just need to trade this like any other symptoms.
Make sure they know about it, they're aware of it.
Let them know if they any problems with that to tell us know
and we'll help them find another treatment option.
So what do you think you should teach your patients about beta blockers?
Well, since we know it directly impacts heart rate,
you wanna make sure they know how to check their pulse before they take the medication
and they know not to take the medication if the pulse is less than 60
unless the health care provider has given them another number.
That means you should check somebody's pulse and their blood pressure
before you give them a beta blocker.
In fact, it's a good advise to check someone's blood pressure any time
before you give them an antihypertensive.
If they're having shortness of breath, they wanna notify the health care provider.
If they're diabetic, make sure they know that a beta blocker
may mask some of the normal signs and symptoms of low blood sugar like tachycardia.
It also might block the body's response to kicking out that stored energy
that normally happens in a sympathetic response.
So these 3 things are really important for patient care
but they're also great areas that you could see a test question.
So make sure you spend some extra time here looking through these,
making sure they make sense to you as to how and why they happen
so you'll recognize it as a patient at risk if they're receiving a beta blocker.