But we're talking about calcium channel blockers in this video. So here’s kinda how they work.
The calcium ion entry causes vasoconstriction and increases the heart rate,
so if you let the calcium go across that channel you're gonna end up with vasoconstriction and increased heart rate.
That will help you remember if we give a calcium channel blocker, we're gonna stop that calcium movement
so we’ll have less vasoconstriction and we’ll have a slower heart rate,
both of those should give us a lower blood pressure because that’s what calcium channel blockers do -
they block that calcium from crossing the myocardial cell membranes and the vascular smooth muscle cells
so we have less vasoconstriction and a lower heart rate when a patient is taking calcium channel blockers.
Cool part is, that dilates those coronary and peripheral arteries where by dilating those coronary arteries,
remember, that’s a big help in lowering blood pressure and helping that heart get more blood to it,
a good oxygenated blood supply because those coronary arteries are dilated.
Calcium channel blockers don’t really have that much of an effect on veins,
so think about the word calcium channel blockers, try circling both a’s -- the one in calcium
and the one in channel and write the word artery in between your two circles
to remind you that that’s what they impact, the arteries, not the veins.
Now you'll see a note in your drawing and that will give you a little bit more information
about how the SA node is impacted and you'll see the calcium channel being blocked
and what happens in the vessels, so stop the video, pause it for just a minute,
take a look at what you see in your notes and in the drawings and make sure
that makes sense to you based on what we've just discussed before you move forward in the video.
Okay, now, in the calcium channel family we have several other different families,
so I just wanna show you how those are broken down,
because not all of the calcium channel blockers have the same exact actions.
This group, the dihydropyridines, act primarily on the arterials at the therapeutic levels.
So if we're giving these medications at therapeutic levels, they primarily act on the arterioles.
Remember from our blood pressure video, those are like the control valves.
So here’s a list of the names that fall under that category.
So by this group of drugs, just put a big giant capital A to remind you that there are just the arterioles at therapeutic levels.
So, in addition to our first family the D’s, you got them right there, so let’s look at the other two families that we have.
These act on the peripheral arteries and the heart. So we've got the Ps and we've got the Bs, okay.
Those are some long last names for you to say, but these two drugs -- verapamil and diltiazem, I really wanna draw your attention to.
Now I'm looking in the list like this and thinking, how am I ever gonna keep this straight?
Well, look at the last four letters of all the ones in the D family. They all end in what?
Good, P-I-N-E. So like remember the ones that ended in P-I-N-E, they are the ones that act primarily on the arteries.
But look at verapamil and diltiazem -- yeah, they are way different.
They're representative of those two other families but they act on the arteries and the heart,
meaning they will directly decrease your heart rate.
So these two drugs, verapamil and diltiazem, will bring your heart rate or your pulse down. That’s important to remember.
I'm gonna get arterioles, whoop!
Dilating with all three of these families but only these two families
and the representatives verapamil and diltiazem, will also bring the heart rate directly down.
Okay, so when you're looking at two big lists like this, look for some way that you can chunk the information
and lump it together that will help you remember more.
You can't try and memorize everyone of these drug names, it’s just not doable
but you can remember, hey, I'm familiar with these drugs, they end in P-I-N-E,
that will help me remember that they're primarily on the arteries and the other drug verapamil and diltiazem, go after both.
Okay, so calcium channel blockers as a whole increase vasodilation.
Now think with me, is that primarily in the veins or the arteries? Good!
It’s in the arteries so we just talked about. They’ll slow cardiac impulse formation.
Now which two specific drug names will slow cardiac impulse formation
and therefore lower my heart rate? Great! Diltiazem and verapamil, you got it.
So how is the afterload decreased by a calcium channel blockers?
Well, anytime I can dilate arterioles, remember those are like the control valves in my blood pressure,
so every time I make those bigger, it’s gonna be easier for my heart,
that left ventricle to push blood out to the rest of my body,
so remember, afterload is the resistance, how tight those vessels are really impacted,
how hard the heart has to work the left side of my body to push the blood out.
If those arterioles are dilated then its gonna have a lot easier job.
Okay, now, there's one unusual thing and I want you to underline that name there -
say, nimodipine -- underline that and I want you to write the words vasospasm right next to it,
just vasospasm and I hope you remember what it is, write headache.
Okay, I know I'm getting kind of bossy, but the reason I want you to remember this is
this is a really unique property of this particular calcium channel blocker.
I had my very best friend in the world ended up preeclamptic which really developed after she delivered the baby.
I know it’s kind of odd but they misdiagnosed with several different things.
They thought that she was leaking from her epidural site, they thought she had four strokes,
they thought -- what she was having was cerebral vasospasms.
So even though she was diagnosed with stroke and MIs, none of that had really occurred.
The changes that they were seeing on her tests were cerebral vasospasm, we were thrilled.
And then she got a calcium channel blocker like this one to help deal with those excruciating headaches.
So, by you knowing these things about medications, you could be thinking through,
why are we giving this calcium channel blocker? What's our goal?
And not just why we are giving this calcium channel blocker, but why are we giving each medication that you give a patient,
because remember you play a pivotal role on the heathcare team.
Now let’s look at three different areas of calcium channel blockers are used.
We just talked about a really specialized one.
Can you recall the name of the drug, the special calcium channel blocker that we used for cerebral vasospasms?
Good job! Nimodipine, you got it.
Now try answering those questions without looking at your notes.
That will help your brain remember more,
but as far as talking about the treatment of hypertension, what we got the medication listed there for you.
Now if we're talking about supraventricular and rapid ventricular rate, that’s what RVR is, we call those anti-dysrhythmics.
We're going against rhythms.
Okay now, do you see any similarities between the ones that we use for anti-dysrhythmia and the ones that we use for hypertension?
Yeah, two of those are the same, but remember because verapamil and diltiazem are two medications
that actually go against your heart rate by bringing it down, that’s why they're really useful with rapid dysrhythmias.
Now long term prevention of angina, we've got diltiazem, nicardipine, nifedipine, verapamil -
you’ve got them there, so look at all three categories, is there any medication that’s in all three categories?
Yeah, there's two, so circle those two -- verapamil, diltiazem, verapamil, diltiazem, verapamil,
diltiazem -- just to kinda help your brain see the pattern.
So we can use calcium channel blockers for high blood pressures, for weird fast heart rhythms, and for long term prevention of angina.
Now based on what you know about calcium channel blockers,
why would a calcium channel blocker help us prevent angina or chest pain attacks?
Pause the video and see if you can write yourself some quick notes.
Good work! I'm glad you're hanging in there and trying to answer these questions.
I promise that will pay off for you that you're studying as you go.
So, why the calcium channel blockers help us with long term prevention of angina?
A couple of things -- dilates those coronary arteries, right?
That’s a really good move and it’ll also bring down your heart rate with a couple of those,
so those will be very helpful in decreasing how much oxygen it needs, the heart needs,
and we've got that really easy blood flow.
So what do you think the side effects are?
Well, we know if we need family, category or class, there are some things are gonna be the same.
Any blood pressure med patients may complain of a headache and they might have some dizziness and some weakness,
particularly this calcium channel blockers dilate those vessels so they might feel a little dizzy.
Now you can have some palpitations and some arrhythmias.
Remember these medications go directly after the electrical conductivity system of the heart
so that’s why we might have some of these palpitations and arrhythmias.
Now anything that drug does the well they can do over well
so we might end with a bradycardia which is slow, right?
Tachycardia is fast, bradycardia is slow.
So because some calcium channel blockers, like diltiazem and verapamil,
directly go after slowing down the heart rate, it could be too slow for your patient.
Also it could cause, if your patient has some underlying heart blocks, this is not a great medication for them
because these meds have the potential to cause bradycardia or possibly a little bit of a type of a heart block.
Orthostatic hypotension, we've talked about this in most all of our videos
But that means your patient’s blood pressure will drop too quickly if they go from lying to sitting,
or sitting to standing without pausing a few seconds in between to make sure that their body is adjusting to the change.
So in orthostatic hypotension, you need to educate your patients, hey, this is normal.
We know you're gonna feel this way, but when you go from lying to sitting, do it slowly,
make sure you feel okay before you stand up because that’s gonna be really important to keep you safe.
Otherwise, you may end up laying back down again really fast on your face and that’s not what we want.
Now, this is kind of an uncomfortable topic but which is really important.
You know that the elderly are usually focused on how well their gut is functioning
and if you don’t know that yet, you will after you care for them for a while,
but if you've never experienced true constipation, you really won't be empathetic
but you need to be because this is miserable and we don’t -- we can help -
we can make sure this doesn’t happen and patients don’t have to go through this
because one of the weird side effects of calcium channel blockers is constipation.
And the elderly populations particularly at risk, so you want them to stay as active as they can,
you want them to stay well hydrated and eat foods that are fresh and healthy and have fiber.