Anti-Thrombotic's

Question 1

What are the 2 types of Anti-Platelet Drugs?

Answer 1

1. COX- Inhibitors- NSAIDS

2. ADP Blockers- very expensive

Question 2

Acetylsalicylic Acid (ASA):

Answer 2

• COX-1 Inhibitor
• The only NSAID used as an anti- thrombotic
• AE’s: Well tolerated at low doses (safety issues with GI Ulceration)

Question 3

Clopidogrel:

Answer 3

• ADP Blocker
• Irreversible P2Y12 Antagonist
• Bleeding Risk/ GI upset

Question 4

Ticagrelor:

Answer 4

• ADP Blocker
• Reversible P2Y12 Antagonist
• Bleeding Risk/ GI upset

Question 5

Anti-Coagulant Drugs:

Answer 5

1. Injectables- directly inhibit factor Xa, or factor Xa and factor IIa (thrombin)
2. Orally- directly Vitamin K, factor IIa and factor Xa

Question 6

Heparins:

Answer 6

Injectable anti- coagulants

• -Unfractionated Heparin (UFH)
• -Low Molecular Weight Heparin (LMWH)
• Safety concerns:
• Bleeding
• Heparin induced thrombocytopenia syndrome (HITS)

Question 7

Unfractionated Heparin (UFH):

Answer 7

Heparin:
Binds Factor IIa (Thrombin)
-Promotes the activity of anti-thrombin (ATIII)

Question 8

Low Molecular Weight Heparin (LMWH):

Answer 8

Enoxaparin

• Subcutaneous administration (easier to administer/ less AE’s)
• Promotes the activity of anti- thrombin (ATIII)
• ->ATIII inactivates Factor Xa

Question 9

Warfarin:

Answer 9

Vitamin K Antagonist

• Inhibits Vitamin K Epoxide Reductase (VKOR) which usually promotes clotting.
• Delayed Effect: Warfarin can’t begin working until all Vitamin K clotting factors are eliminated (takes time as Thrombin has a high half life)
• High likelihood of DDI’s with drugs and food
• Metabolized by P450 CYP enzymes
• International Normalized Ratio of (2-3)
• Must avoid foods high in Vitamin K

Question 10

International Internalized Ratio:

Answer 10

High INR: less coagulation- thin blood- bleeding risk

Low INR: more coagulation- thick blood- higher likelihood for stroke/ MI

Question 11

Dabigatran:

Answer 11

--Direct Oral Anti-Coagulants (DOAC)
Direct Thrombin (Factor IIa) inhibitor (DTI)

Question 12

Rivaroxaban:

Answer 12

–Direct Oral Anti-Coagulant (DOAC)

Factor Xa Inhibitor

Question 13

What is the downside to DOAC’s?

Answer 13

-Although they don’t USUALLY require monitoring, they don’t have a reliable method for monitoring INR like injectables.

Question 14

Tissue Plasminogen Activator (tPA):

Answer 14

-Increase plasminogen leading to the production of plasmin and the breakdown of Fibrin Mesh