Pharmacology, part 6: Cardiovascular Medications - Hypertension & Angina

In this video, we are going to talk about more medications that are used to treat hypertension. Specifically, we'll be talking about calcium channel blockers, alpha-2 agonists, beta-1 blockers, and non-selective beta blockers. If you are following along with cards, I'm on card number 15 in the Edition 2.0 deck.

Alright. Now let's talk about calcium channel blockers. So medications that fall within this class include verapamil, nifedipine, and diltiazem. And the way that I remember that these medications are calcium channel blockers is I think, "Calcium channel blockers are very nice drugs." So V for verapamil, N for nifedipine, and D for diltiazem. So these medications are used to treat hypertension as well as angina. And then nifedipine is also used to treat pre-term labor. So the mode of action of calcium channel blockers are to block calcium channels in the heart and in the blood vessels. This results in vasodilation and a decrease in the heart rate. Key side effects include peripheral edema. That's a really important one to know. As well as hypotension, which you probably could have guessed, right? Anytime we have a medication that treats hypertension and it does its job too well, hypotension is likely going to be a key side effect. Other side effects include bradycardia because we're affecting the heart rate, as well as headache and constipation. So important teaching that you need to do for your patient, you need to advise them not to consume grapefruit juice. And you're definitely going to want to monitor their blood pressure, as well as their heart rate, carefully during therapy.

Alright. Now we're going to talk about a centrally-acting alpha-2 agonist. So the medication to know in this class is clonidine. It's going to be really important that you not mix up clonidine with clozapine. So clozapine with a Z is for schizophrenia which also has a Z. Clonidine does not have a Z. It's not for schizophrenia. It's for hypertension, okay? So we use this for hypertension. It works by decreasing the sympathetic outflow to the heart and blood vessels which results in decreased heart rate and decreased blood pressure. The key side effects to remember are the 3 Ds of clonidine. And this includes dizziness, drowsiness, and dry mouth. So again, 3 Ds of clonidine. And one important teaching to give your patient is that they can suck on hard candy or chew gum for a dry mouth.

Alright. Now let's talk about beta-1 blockers which include metoprolol, as well as atenolol. So next we'll be talking about non-selective beta blockers. The way that you can remember which medications are beta-1 blockers is that you only have one mother. You might actually have more than one mother. But let's say you have one mother or one ma. And that will help you remember that beta-1 blockers are metoprolol and atenolol, which start with M and A. So these medications are used for hypertension, angina, a heart failure as well as a myocardial infarction. The mode of action is that they block beta-1 receptors which are on the heart, right. You only have one heart so those are beta-1 receptors. And this helps to decrease blood pressure as well as heart rate. So side effects of this medication include bradycardia, hypotension, fatigue, and erectile dysfunction. This medication also carries a black box warning because if you discontinue taking this medication abruptly, it can cause angina as well as an MI. So it's going to be important to teach your patient to change positions slowly because of that hypotension. You're also going to want to monitor their blood pressure and pulse during therapy. And also keep in mind that beta-1 blockers can mask signs of hypoglycemia. So if you have a patient who has diabetes, this is going to be an important point to know.

Now let's talk about non-selective beta blockers. So these are beta blockers that not only affect beta-1 receptors in the heart, they also affect beta-2 receptors in the lungs. So medications that fall within this class include propranolol, labetalol, and carvedilol. So again, they all end in that -olol, but it's important to know how you can determine that these are non-selective as opposed to the beta-1 blockers that we talked about last. So if you recall with the beta-1 blockers, you have 1 ma, in all likelihood. So beta-1 blockers include metoprolol as well as atenolol. For non-selective beta blockers, the way I remember this is I think, "Please listen carefully." And that helps me remember propranolol, labetalol, and carvedilol. "Please listen carefully." These medications not only affect the beta-1 receptors, they also affect the lungs too. And that's going to be a really important point with these non-selective beta blockers. So they are used to treat hypertension, angina, as well as arrhythmias or an MI. They work by blocking the beta-1 receptors in the heart as well as the beta-2 receptors in the lungs. They decrease blood pressure and heart rate. But a key side effect, and one that's really important for you to know, is bronchospasm. Because they are affecting those beta-2 receptors in the lungs, you would never want to give this medication to someone who had asthma or issues that would be exacerbated by bronchoconstriction. Other side effects include fatigue, hypotension, bradycardia, as well as erectile dysfunction. And again, no using this medication for patients with asthma because of that bronchospasming because we are affecting the lungs too.

Alright. In my next video, we are going to talk about vasodilators that are used for angina as well as a hypertensive crisis. So hang in there with me.