Antithrombotic Drugs

Question 1

Elimination of UFH

Answer 1

Liver and kidney

Question 2

Elimination of LMWH

Answer 2

Kidney

Question 3

What is the preferred anticoagulant during pregnancy?

Answer 3

LMWH

Question 4

Elimination of Fondaparinux

Answer 4

Kidney

Question 5

How is warfarin monitored?

Answer 5

INR. Goal is 2-3.

Question 6

2 major side effects of warfarin

Answer 6

Microvascular skin necrosis - due to early drop in APC –> hypercoagulability. Increased risk in females. Occurs during first week.
Teratogen

Question 7

Treating warfarin overdose (4)

Answer 7

• Prothrombin complex concentrate – Preferred method. Concentrated VII, IX, X, and II.
• Vitamin K
• Fresh frozen plasma
• Recombinant VII – very expensive. High risk of thrombosis.

Question 8

Argatroban
Type
Use
Monitoring?

Answer 8

Direct thrombin inhibitor
Mainly used to treat HIT
Monitor w/ aPTT

Question 9

Dabigatran
Type
Monitoring?

Answer 9

Direct, reversible inhibitor of thrombin

No monitoring

Question 10

Rivaroxaban

Type

Answer 10

Direct, reversible X inhibitor

Question 11

Apixaban

Type

Answer 11

Reversible X inhibitor

Question 12

3 things that cause release of arachidonic acid

Answer 12

ADP, thrombin, and fibrinogen

Question 13

Clopidogrel
Brand name
Metabolism
Mechanism
Use
Side Effects

Answer 13

Plavix
Prodrug, activated in liver
Mechanism - irreversibly blocks ADP receptor on platelets. Lasts 5-10 days.
Use - prevents stroke (better than aspirin), MI, and coronary stent occlusion
Side effects -
• Immunologically mediated thrombocytopenia / neutropenia
• GI / intracranial bleed
• Inhibits P450 → drug interactions

Question 14

Abciximab
Mnemonic
Mechanism
Use

Answer 14

“Abc, (1), 2, 3” like Jackson 5 song.
Mechanism - Fab portion of mAb inhibits GpIIB/IIIa, thus blocking binding of fibrinogen and blocking platelet AGGREGATION.
Use - Used to prevent coronary occlusion during percutaneous coronary intervention and in refractive unstable angina

Question 15

2 brand names for LMWH

Answer 15

Enoxaparin and Dalteparin

Question 16

2 brand names for recombinant tPA

Answer 16

Alteplase and Reteplase

Question 17

What should be given along w/ fibrinolytics?

Why?

Answer 17

Clot lysis may expose clot-bound thrombin → enhanced platelet activation / aggregation, so often given w/ antiplatelet / antithrombotic drugs, such as aspirin / heparin.

Question 18

Desmopressin
Type of drug
Mechanism
Use

Answer 18

Hemostatic drug (increases clotting)
Mechanism - promotes release of vWF and VIII from endothelial cells
Use - vWD, mild hemophilia A (low VIII), and thrombocytopenia

Question 19

Aminocaproic Acid / Tranexamic Acid
Type of drug
Mechanism
Use

Answer 19

Hemostatic drug (increases clotting)
Mechanism - inhibits plasmin activation
Use - Excessive post-op bleeding, reduces blood loss during coronary bypass, stops bleeding from thrombolytics, and prevents bleeding from severe / chronic thrombocytopenia.

Question 20

Activated VII
Mechanism
Use
Side effects

Answer 20

Mechanism - Promotes hemostasis by augmenting TF-dependent thrombin generation
Uses - Hemophilia pxs w/ Abs against replacement factors, Pxs w/ acquired VIII inhibitor, Uncontrollable / intracranial bleeding
Side effect - thrombosis

Question 21

Use of Vit K

Answer 21

Used for elevated INR (such as warfarin overdose) and pxs w/ serious bleeding