12-06 L3 Blood Clotting Antiplatelets Anticoagulation

Question 1

unfractionated heprin

MOA

Answer 1

acts via enhancement of antithrombin

(irreversibly inactivates Xa and IIa)

Question 2

antithrombin III

Answer 2

is a serine protease inhibitor, clotting factor attacks antithrombin III

Question 3

What is the drug of choice in anticoagulation for pregnancy?

Answer 3

Unfractionated heparin

Question 4

What do you use to treat sever bleeding caused by heparin?

Answer 4

• Protamin sulfate (basic)

Question 5

how does heparin cause thrombocytopenia

Answer 5

heprain binds to platelet factor 4 complex

immune recognizes it as foregin

Question 6

LMWH

MOA

Answer 6

inhibition of Xa

Question 7

LMWH

drug of choice for what?

Answer 7

• Prophylaxix
• treatment of DVT/PE
• Management of acute coronary syndrome

Question 8

Wafarin is adminstered how?

Answer 8

orally

Question 9

Warfarin

MOA

Answer 9

interferes with the normal posttranslational modification of clotting factors in the liver

(a process that depends on vit. K)

Question 10

How do you monitor heprin and warfarin?

Answer 10

• heprin: aPTT
• Warfarin: PT

Question 11

What is a major countra-indication of warfarin

Answer 11

• Do not use in pregnancy
• aborption, severe birh defect,
• UFH or LMWH are alternatives

Question 12

Warfarin drug interactions

Answer 12

• responsible for more adverse drug interactions than any other drugs (goes to war with all the other drugs)
• P450 inhibitors: increase activity, e.g ASA
• P450 activators: decreases activity e.g. barbiturates

Question 13

Dabigatran

Indication

MOA

Answer 13

• Indication: 1st alternative oral anticoagulant
• MOA: direct thrombin inhibitor

Question 14

Fondaparinux (arixtra)

admin

MOA

Answer 14

• Parenteral (subcutaneous) shot
• selective FXa inhibitor

Question 15

Streptokinase

MOA

Answer 15

• binds plasminogen
• exposes active site
• promotes conversion of additional plasminogen to plasmin

Question 16

t-PA

MOA

Answer 16

serine protease, naturally occuring regulator of thrombolysis

converts plasminogen to plasmin

Question 17

Tenecteplase

(t-PA modified)

Answer 17

• increases activity (K)-H-R-R
• Increases 1/2 life: T and N mutation

Question 18

What doe you use to manage bleeding caused by t-PA?

what is the MOA of this drug

Answer 18

Aminocaproic acid

(binds to plasminogen and plasmin, blocks access of fibrin)

Question 19

Aspirin

MOA

Answer 19

irreversible inhibition of COX-1 and AA–> TXA2

Question 20

Clopidogrel

MOA

Pharmacokinetics

Answer 20

• MOA: a pro drug, irreversible inhibition of P2Y12 ADP receptor
• Pharm: rapid absorptoin, aggregation returns to normal at 5 days post-DC

Question 21

ABCIXIMAB

• MOA
• Indication
• Toxicities

Answer 21

• MOA: monoclonal antibody that reversibly inhibits the binding of fibrin and other ligands to the GP2b/3a receptor
• Indications: typically used during PCI such as stent placement
• Toxicities: Bleeding, thrombocytopenia