Pharmacology, part 11: Cardiovascular Medications - Anticoagulants & Antiplatelets

by Cathy Parkes

In this article, we cover cardiovascular medications - anticoagulants and antiplatelets. Anticoagulants slow down clotting, thereby reducing fibrin formation, preventing clots from forming and growing. Antiplatelet agents prevent platelets from clumping together and also prevent clots from forming and growing. The Nursing Pharmacology video series follows along with our Pharmacology Flashcards, which are intended to help RN and PN nursing students study for nursing school exams, including the ATI, HESI, and NCLEX. 

Factor Xa inhibitors - rivaroxaban, apixaban

Factor Xa inhibitors are a class of anticoagulant drugs that act directly upon factor Xa, which is an enzyme of the coagulation cascade. Medications that fall within this class include rivaroxaban (Xarelto) and apixaban (Eliquis). They can be used to prevent a deep vein thrombosis (DVT), a stroke or a pulmonary embolism (PE) in patients who have atrial fibrillation.

Mode of action

Factor Xa inhibitors like rivaroxaban and apixaban work by selectively and reversibly blocking the activity of the clotting factor Xa, which blocks the coagulation cascade. They affect both factor Xa within the blood and within preexisting clots, effectively preventing clots from increasing in size. Factor Xa is generated by both the extrinsic (activated by external trauma that causes blood to escape from the vascular system) and intrinsic (activated by trauma inside the vascular system) coagulation pathways and is responsible for activating prothrombin to thrombin.

Cool ChickenRivaroxaban helps your blood flow like a river by inhibiting factor Xa.

Side effects

The main side effect of rivaroxaban (Xarelto) and apixaban (Eliquis) is bleeding. Anytime a patient is taking an anticoagulant they’ll be at higher risk of bleeding due to the thinning of the blood. Another possible side effect patients may experience with this medication is elevated liver enzymes, which often indicate inflammation or damage to cells in the liver.

Bleeding precautions

Any patient who is on anticoagulants should also be placed on bleeding precautions and educated on what that means. Patients on bleeding precautions should use an electric razor and a soft-bristled toothbrush at home, and immediately report any signs of bleeding. These signs include oozing at the gumline, coffee-ground emesis (vomit), amber-colored urine, black/tarry stool, and large hematomas.

Patients should also be taught to seek emergency care for any head trauma, even if it is perceived to be small. In the hospital, nurses should minimize needle sticks, use small (22ga) needles, and assess the patient's output for signs of bleeding.

Black box warning

This medication carries a black box warning because if you abruptly discontinue use, it places the patient at higher risk for thrombotic events such as a stroke or a pulmonary embolism (PE).

Nursing care

When a patient is on this medication, their liver function should be monitored due to the possible side effect of elevated liver enzymes. The patient's hemoglobin and hematocrit levels should also be monitored during therapy. Hemoglobin is the oxygen-carrying protein in red blood cells and hematocrit is the proportion of red blood cells to the fluid component, or plasma, in your blood. 

Platelet aggregation inhibitors/antiplatelets - clopidogrel, abciximab

Platelet aggregation inhibitors are a class of drugs that decrease platelet aggregation and inhibit thrombus formation. Platelet aggregation is the clumping together of platelets in the blood and is part of the sequence of events leading to the formation of a thrombus or clot. Medications that fall within the class of platelet aggregation inhibitors are clopidogrel (Plavix) and abciximab. 

Mode of action

Platelet aggregation inhibitors work in different places of the clotting cascade and prevent platelets from sticking together to form unwanted blood clots that could block an artery. 

Cool Chicken Horse clops on platelets to prevent them from aggregating.

Side effects

As with any anticoagulant or antiplatelet medication, the main side effect for both of these medications is increased bleeding. With abciximab, patients can also have hypotension as well as dysrhythmias. With clopidogrel, patients can experience both GI upset and rashes.

Nursing care

A patient's EKG and vital signs should be monitored closely while on abciximab due to the side effects of hypotension and dysrhythmias. 

To learn how to interpret EKG results, check out our EKG Flashcards for Nursing Students.

Thrombin inhibitors - argatroban, dabigatran

Thrombin inhibitors are a class of anticoagulant medications that bind to and inhibit the activity of thrombin, preventing clot formation. Two medications that fall within this class include argatroban and dabigatran (Pradaxa). They can be used to treat a deep vein thrombosis (DVT), a pulmonary embolism (PE), help prevent a stroke and can be used with heparin-induced thrombocytopenia or HIT.

Mode of action

Thrombin inhibitors like argatroban and dabigatran (Pradaxa) work by blocking thrombin receptors, which prevents the activation of clotting factors and decreases thrombus (clot) formation. 

Side effects

As with the other anticoagulant and antiplatelet medications in this article, the main side effect of both these medications is increased bleeding. Argatroban has an additional side effect of hypotension, while dabigatran can result in GI upset and angioedema, which is the swelling of the lower layer of skin and tissue just under skin or mucous membranes.

Cool Chicken There is no time to argue….. You can’t just dab at the blood. You need to hold pressure to stop the bleeding from argatroban and dabigatran!

Nursing care

As with other anticoagulant and antiplatelet medications, the key thing to monitor when a patient is on these types of medications is increased bleeding.


Full transcript

Hi. In this video, we are going to continue covering some hematologic medications. Specifically, I'll be talking about a few more anticoagulant and antiplatelet medications.

So let's start off by talking about factor Xa inhibitors. Medications that fall within this class include rivaroxaban as well as apixaban, which is Eliquis.

So these medications are used to prevent a DVT, a stroke, or a PE in patients who have atrial fibrillation.

They work by selectively inhibiting factor Xa, which helps to block the coagulation cascade.

So the way I remember at least one of these medications, rivaroxaban, it looks like river. So if you take rivaroxaban, it will help your blood flow like a river because it's going to thin it out.

So side effects, bleeding is the big one to remember here. Anytime we have an anticoagulant, bleeding is always going to be a risk if we thin the blood too much, right, we do too much anticoagulation.

Another side effect is possible elevated liver enzymes with this medication.

In addition, this class of medication carries a black box warning because if you abruptly discontinue to use this medication, it places the patient at higher risk for thrombotic events.

So when your patient is on this medication, you want to monitor their liver function because of the risk of elevated liver enzymes. You're also going to want to monitor their hemoglobin and hematocrit during therapy.

Alright. Now let's talk about platelet aggregation inhibitors or antiplatelets. So the two medications that I'd be familiar with, that fall under this class, include clopidogrel and abciximab.

So abciximab is the medication that's spelled kind of funky. It's A-B-C and then so on which makes you wonder how they come up with these names. But that's what it is.

So these medications are used to prevent an MI or a stroke in patients who have acute coronary syndrome.

They work by inhibiting platelet aggregation.

So when I think about the medication clopidogrel, it looks like clop. The first of part of it, so I think about a horse clopping on platelets and preventing them from aggregating. So that's my little, silly way of remembering what clopidogrel does, what it's mode of action is.

So side effects with both of these medications: bleeding, right? Any time we have a anticoagulant or an antiplatelet, bleeding is going to be a key side effect.

With abciximab, you can also have hypotension tension as well as dysrhythmias and with clopidogrel, GI upset and rash are other side effects as well.

So if your patient is on one of these medications, you are definitely going to want to assess for bleeding.

And then, for abciximab, you're also going to want to pay attention to your patient's EKG and their vital signs because of the side effects of hypotension and dysrhythmias.

Alright, now let's talk about thrombin inhibitors. Two medications that fall within this class include argatroban and dabigatran.

These medications can be used to treat a DVT, a PE, they can help prevent a stroke, and they are also used with HIT or heparin-induced thrombocytopenia.

Their mode of action is to block thrombin receptors which helps to prevent the activation of clotting factors and the formation of a clot.

The key side effect with both of these medications is bleeding.

In addition, with argatroban, hypotension is a possible side effect, and with dabigatran, GI upset and angioedema are also possible side effects.

So the way I remember these medications and the key side effect of bleeding is I say, "There is no time to argue. You can't just dab at the blood. You need to hold pressure to stop the bleeding from argatroban or dabigatran. So again, key side effect is bleeding and anytime your patient is bleeding, you need to hold steady pressure on that area in order to stop the bleeding.

So the key thing you're going to be doing when a patient is on this therapy is assess for bleeding just like we've done with these other anticoagulants that we've talked about.

Okay. In my next video, we will be wrapping up our hematologic medications. We'll be talking about a hemostatic agent as well as a thrombolytic medication, and then we'll also be covering erythropoiesis, growth factors, and leukopoietic growth factors as well. So hang in there with me!


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