Parenteral Anticoagulation Drugs

Question 1

How do anticoagulant drugs work?

Answer 1

They prevent the formation of fibrin which is needed to clot blood

Question 2

What is another name for an anticoagulant?

Answer 2

Antiothrombotic

Question 3

Which 3 drugs interrupt the conversion of fibrinogen to fibrin?

Answer 3

-Unfractionated heparin
-Low-molecular weight heparin
-Fondaparinux heparin

Question 4

How does heparin prevent clots?

Answer 4

-Heparin binds with antithrombin III which inactivates thrombin
-This inhibits the conversion of fibrinogen to fibrin
-Clot is prevented

Question 5

What are contraindication for heparin therapy?

Answer 5

-Uncontrollable bleeding
-Hemorrhagic cerebrovascular accident
-Thrombocytopenia (low platelet count)
-Before, during, or after surgery involving the eyes, spine, or brain
-Before, during, or after lumbar puncture

Question 6

What drugs have serious interactions with heparin?

Answer 6

-Other anticoagulants
-Platelet aggregation inhibitors
-NSAIDs
-Thrombolytics
-Antibiotics

Question 7

What is a normal aPTT value?

Answer 7

25-38 seconds

Question 8

What is a therapeutic aPTT value for someone taking heparin therapy?

Answer 8

1.5-2xs normal

Question 9

What is important to remember when administering SQ heparin in the abdominal area?

Answer 9

Don’t administer it within 2 inches of the belly button

Question 10

What can be administered as an antidote to a patient that has active bleeding during heparin therapy?

Answer 10

Protamine sulfate

Question 11

What is HIT?

Answer 11

Heparin-induced thrombocytopenia; dangerously low platelet count due to heparin

Question 12

What are the symptoms of HIT?

Answer 12

-Bleeding gums
-Bruising
-Bloody urine/stool
-Anxiety

Question 13

When should aPTT be assessed after initiating heparin?

Answer 13

4-6 hours after

Question 14

Name a Vitamin K Anticoagulant

Answer 14

Warfarin

Question 15

What is the difference between Warfarin and Heparin?

Answer 15

-They work on different parts of the clotting cascade
-Warfarin doesn’t require strict monitoring

Question 16

What is the lab test that is performed before Warfarin is adminisitered?

Answer 16

INR; International Normalized Ratio

Question 17

Describe how Vitamin K Anticoagulants (like Warfarin) work

Answer 17

-Vitamin K is needed in order to make clotting factors
-Warfarin interferes with Vitamin K-dependent clotting factors; it also depletes Vitamin K reserves

Question 18

How long does it take Warfarin to clear from the body?

Answer 18

4-5 days

Question 19

What is a good INR for a patient taking Warfarin?

Answer 19

2-3

Question 20

What is the only Oral Direct Thrombin Inhibitor?

Answer 20

Dabigatran

Question 21

Name 3 Factor Xa Inhibitors

Answer 21

Rivaroxaban
Apixaban
Edoxaban

Question 22

How does Dabigatran work?

Answer 22

Directly inhibits thrombin by preventing the conversion of fibrinogen to fibrin

Question 23

How does the Factor Xa Inhibitors work?

Answer 23

Directly inhibit Xa preventing the conversion of prothrombin to thrombin

Question 24

What are contraindications of Warfarin?

Answer 24

-Thrombocytopenia
-Lumbar puncture; regional anesthesia; surgery of eye, spine, or brain
-Vitamin K deficiency, liver disease, alcoholism
-Pregnancy

Question 25

What are some drugs that interfere with Warfarin?

Answer 25

Aspirin NSAIDs Sulfonamides Cimetidine Allopurinol Foods high in Vitamin K

Question 26

What are common side effects of Warfarin?

Answer 26

Bleeding GI upset

Question 27

What are adverse drug effects of warfarin?

Answer 27

Intracranial bleeding Retroperitoneal bleeding

Question 28

What is the antidote for a Warfarin overdose?

Answer 28

Vitamin K

Question 29

At what INR value should you hold Warfarin?

Answer 29

Greater than 3

Question 30

At which age can patients take Dabigatran and Rivaroxaban?

Answer 30

18 and older

Question 31

What are contraindications for Dabigatran and Rivaroxaban?

Answer 31

Active major bleeding Mechanical prosthetic heart valve

Question 32

What are drug interactions of Dabigatran and Rivaroxaban?

Answer 32

-Rifampin can decrease drug concentrations -Antacids and PPIs and decrease drug effects -Antiplatelets, NSAIDs, and other anticoags can increase bleed risks

Question 33

At what dose should you give Rivaroxaban with foods?

Answer 33

10mg+

Question 34

If a patent is actively bleeding from Warfarin and not responding to Vitamin K, what should we give them?

Answer 34

Fresh-frozen plasma

Question 35

What is the antidote for Dabigatran?

Answer 35

Idarucizmab

Question 36

What are antiplatelet drugs?

Answer 36

Drugs that suppress platelet aggregation and used in the prevention of thrombosis. They make platelets less sticky so they don't form clots

Question 37

What are antiplatelet drugs used for?

Answer 37

- Prevention of MI - Prevention of ischemic stroke

Question 38

What are the 3 classes of Antiplatelet Drugs? Give a drug name for each

Answer 38

-COX Inhibitor; Aspirin - ADP Receptor Blockers; Clopidogrel -GP IIb/IIIa Receptor Blockers; Tirofiban

Question 39

What are contraindications for Clopidogrel?

Answer 39

Active bleeding

Question 40

What drug interactions are there with Clopidogrel?

Answer 40

-Aspirin, NSAIDs, Warfarin may increase bleed risk -Grapefruit may lessen effects

Question 41

What do thrombolytic drugs do?

Answer 41

They disintegrate existing blood clots

Question 42

Name a thrombolytic drug

Answer 42

Alteplase

Question 43

Explain how alteplase works

Answer 43

Alteplase binds with plasminogen which activates plasmin. Plasmin is an enzyme that disintegrates the fibrin network of blood clots

Question 44

What conditions is Alteplase used for?

Answer 44

Acute MI Acute ischemic stroke Large, acute PE Clear clots from central venous catheters

Question 45

What are absolute contraindications of Alteplase?

Answer 45

Cranial lesions History of ischemic stroke within 3 months Active internal bleeding Suspected aortic dissection Uncontrolled hypertension

Question 46

What can be used as an antidote to severe bleeding in a patient taking thrombolytic therapy?

Answer 46

Aminocoproic acid