PBL Drugs 2

Question 1

What is the MOA of warfarin?

Answer 1

Interferes with normal synthesis and gamma-carboxylation of Vitamin K-dependent clotting factors II, VII, IX and X and proteins C and S.
-Has effect on Extrinsic pathway thus increasing your PT

Question 2

What do you have to remember with Warfarin?

Answer 2

Must bridge with Heparin because it will inhibit Protein C first, making you more susceptible to clotting.

Question 3

What is the MOA of Heparin?

Answer 3

Cofactor for the activation of antithrombin, decreases activity of thrombin and factor Xa. Will increase your PTT.

Question 4

How do you reverse the effects of Heparin?

Answer 4

Administer Protamine!

Question 5

What are two LMW heparins?

Answer 5

-APARIN in the name
Enoxaparin
Dalteparin

Question 6

What is the MOA of low molecular weight heparin?

Answer 6

Similar to Heparin but acts more on factor Xa. Have longer half-life and not as easily reversible.

Question 7

What are two Xa inhibitors?

Answer 7

-XA in the name
Apixaban
Rivaroxaban

Question 8

What is the MOA of Xa inhibitors?

Answer 8

Binds directly to factor Xa in the coagulation cascade and inhibits its action (activating factor II).
-Will increase BOTH your PT and aPTT

Question 9

What is the MOA of Argatroban and Bivalirudin?

Answer 9

Inhibits thrombin directly

Question 10

What is the MOA of tPA?

Answer 10

Stimulates the conversion of plasminogen to plasmin –> clot buster!
-Cleavage of fibrin mesh and destruction of coagulation factors.

Question 11

What is the MOA of Fondaparinux?

Answer 11

Anticoagulation results from inhibition of factor Xa by antithrombin III bound to fondaparinux –> Neutralization of coagulation factor Xa inhibits the conversion of prothrombin to thrombin –> and subsequent thrombus formation. [cannot lyse established thrombi or inactivate thrombin]
–> Platelet function and global clotting tests unaffected (PT, bleeding time, aPTT)