Anticoagulant Drugs

Question 1

Unfractionated heparin

Mechanism of action:

Answer 1

Enhance ability of antithrombin to inhibit thrombin, factor 10a and factor 9a
Binds both AT and thrombin
Binds only At NOT factor 10a

Question 2

Anticoagulant effect of heparin reversed by

Answer 2

protamine

Question 3

Can be used safely during pregnancy

Answer 3

Heparin, LMWH

Question 4

Can be used with renal failure

Answer 4

UFHeparin b/c metabolized quickly

Question 5

Monitored by specialized assay, NOT APTT

Answer 5

LMWH

Question 6

Monitored by APTT

Answer 6

UFH

Question 7

LMWH cleared by:

Answer 7

kidney

Question 8

LMWH mechanism of action:

Answer 8

Enhance ability of antithrombin to inhibit factor Xa

NO template system

Question 9

Adverse effects of heparins

Answer 9

Bleeding
Osteoporosis
Heparin induced thrombocytopenia

Question 10

Heparin induced thrombocytopenia =

Answer 10

prothrombotic condition mediated by IgG ab that bind to platelet factor 4 when complexes w/ heparin –> paradoxically causes low platelets and thrombosis

Question 11

Fondaparinus

Answer 11

Synthetic LMWH like drug that does not cross react with HIT ab

Question 12

Warfarin mechanism of action:

Answer 12

Inhibit glutamate carboxylatation of vit K-dependent clotting factors (2, 7, 9, 10)–> impaired synthesis of active procoagulants.

Also inhibit synthesis of vit K-dependent ANTIcoagulants (protein C, protein S)

Question 13

Warfarin metabolized by:

Monitored by:

Answer 13

liver and kidney

INR of PT

Question 14

Limitations of warfarin

Answer 14

Narrow therapeutic index
Many drug interactions
Frequent monitoring
Not safe in pregnancy 
Slow onset , long half life: difficult to manage

Question 15

Parenteral direct thrombin inhibitors

Answer 15

Argatroban
Lepirudin
Bivalirudin

Question 16

Oral direct thrombin inhibitor

Answer 16

Dabigatran

Question 17

Direct thrombin inhibitor(s) metabolized by liver

Answer 17

Argatroban

Question 18

Direct thrombin inhibitor(s) metabolized by kidney

Answer 18

Lepirudin

Bivalirudin

Question 19

Parenteral direct thrombin inhibitors 
Treats:
Administration:
Monitoring:
Halflife

Answer 19

Heparin-induced thombocytopenia
Continuous IV
APT
Short

Question 20

Direct factor 10a inhibitors (2)

Answer 20

Rivaroxaban

Apixaban

Question 21

Dabigatran should be avoided in patients with

Answer 21

kidney disease

Question 22

Asprin =

Mechanism of action:

Answer 22

Anti-platelet anticoag

Irreversibly inhibit cyclooxygenases –> decrease thrombaxane A2 (potent platelet agonist)

Question 23

Clopidorgel, ticlopidine, prasugrel =

Mechanism of action:

Affinity:

Instructions:

Answer 23

P2Y12 receptor antagonist

Block activation of platelets by reducing ADP activation of P2Y12 receptor

High affinity binding: irreversible

Must hold for 7-10 days before sx

Question 24

Ticagrelor=

Mechanism of action:

Affinity:

Instructions:

Answer 24

P2Y12 receptor antagonist

Block activation of platelets by reducing ADP activation of P2Y12 receptor

Reversible: noncompetitive inhibitor

No need to hold for more than 1 day before sx

Question 25

Abciximab, tirofiban, eptifibitide = Mechanism:

Answer 25

Anti-platelet glycoprotein IIb/IIIa antagonists Inhibit binding of fibrinogen to glycoprotein IIb/IIIa

Question 26

Dipyridamole:

Answer 26

Anti-platelet Vasodilatory effect on blood vessel Headache Combo w/ aspirin

Question 27

Fibrinolytic Agents mechanism:

Answer 27

promote activation of plasminogen to generate plasmin --> degrades fibrin

Question 28

Streptokinase = Mechanism: Specificity: Adverse reaction:

Answer 28

Fibrinolytic agent Complex with plasminogen --> allosterically active to generate plasmin Not fibrin specific Allergic reaction Hypotension

Question 29

Urokinase (u-PA) = Mechanism: Adverse reaction:

Answer 29

Fibrinolytic agent Directly cleaves plasminogen to form plasmin Not fibrin specific

Question 30

Tissue plasminogen activator (t-PA): Mechanism: Adverse reaction:

Answer 30

Most common fibrinolytic agent Directly cleaves plasminogen to form plasmin Relative fibrin-specific --> less risk of bleeding