Term
| What are the 5 ways which endothelial cells maintain a nonthrombogenic lining? |
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Definition
| 1) protein C activity, 2) Proteoglycan production (similar to warfarin), 3) Transmural electric charge to repel platelets, 4) release of prostacyclin, 5) Release of plasminogen activators |
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Term
| What are the three phases of Hemostasis? |
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Definition
| Vascular, Platelet, and Coagulation |
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Term
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Definition
| A pathological process in which the platelet aggregate and/or a fibrin clot occludes a blood vessel |
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Term
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Definition
| Emboli are migrating Thrombi |
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Term
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Definition
| Embolism blocks a vessel, Emboli hasn't yet |
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Term
| Name the Anti-Platelet drugs |
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Definition
| Aspirin, Dipyridamole, Ticlopidine, Clopidogrel, Abciximab, Eptifibatide, Tirofiban |
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Term
| What is the mechanism of the antiplatelet drug Aspirin? |
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Definition
| Block of Platelet Cyclooxygenase (COX) to inhibit release of TXA2 |
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Term
| COX produces what two prostaglandins and from where? |
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Definition
| PGI2 from endothelial cells (inhibits platelets) and TXA2 from platelets (promotes platelet aggregation) |
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Term
| Why does inhibition of COX not affect endothelial cells as much as platelets? |
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Definition
| Endothelial cells can produce new proteins while platelets cannot (no nucleus) |
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Term
| What is the mechanism of antiplatelet drugs Ticlopidine and Clopidogrel? |
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Definition
| They increase intracellular cAMP through the inhibition of P2Y-12 receptor on Adenylyl cyclase |
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Term
| When is Ticlopidine and Clopidogrel used? |
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Definition
| When the patient has not tolerated aspirin or to use in conjunction with aspirin |
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Term
| What is the mechanism of the antiplatelet drug Dipyridamole? |
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Definition
| Inhibition of Phosphodiesterase activity to increase intracellular cAMP |
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Term
| What is the ideal antiplatelet drug combo for Prosthetic heart valves? |
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Definition
|
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Term
| What is the ideal antiplatelet drug combo for a Prior Stroke? |
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Definition
|
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Term
| What is the ideal antiplatelet drug combo for Angioplasty? |
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Definition
|
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Term
| What are the three Glycoprotein IIb/IIIa ("sticky integrin") inhibitors (Antiplatelet drugs)? |
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Definition
| Abciximab, Eptifibatide, and Tirofiban |
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Term
|
Definition
| Precutaneous Angioplasty for coronary thromboses |
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Term
| When is Eptifibatide used? |
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Definition
| Unstable Angina and for angioplastic coronary interventions |
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Term
| What is the main Vit. K Antagonist that is an anticoagulant? |
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Definition
|
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Term
| What are the two major side effects of Warfarin? |
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Definition
| Hemorrhage and Birth Defects (because it moves across the placenta) |
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|
Term
| What can be given for Warfarin overdose? |
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Definition
|
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Term
| What factors is Vit. K implicated in? |
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Definition
| II, VII, IX, X, Protein C, Protein S, Z protein (extrinsic and intrinsic pathways) |
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|
Term
| How does Vit. K act to induce clotting? |
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Definition
| It adds gamma carboxyglutamic residues on to proteases to activate them |
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Term
| What is the normal role of Thrombin? |
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Definition
| It removes small fibrinopeptides from fibrinogen to form the active Fibrin form as well as activation of factor XIII which, in the presence of Ca will strengthen the fibrin links |
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Term
| Thrombin activity on platelets causes what? |
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Definition
| Aggregation and generation of arachidonic acid |
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Term
| How does the anticoagulant Heparin work? |
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Definition
| Heparin accelerates the interaction of Antithrombin with proteases that inhibit Thrombin, IXa, and Xa to prevent blood clots in vitro and in vivo |
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Term
| Where is Heparin absorbed in the body and how is it administered? |
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Definition
| Absorbed in the RES; administered as Heparin Sodium Injection |
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Term
| Does Heparin cross the placenta? |
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Definition
| No, safe to use in pregnancies |
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Term
| What are the major adverse reactions to heparin? |
|
Definition
| Hemorrhage and Thrombocytopenia |
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|
Term
| What compound will inhibit the effect of Heparin in case of overdose? |
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Definition
|
|
Term
| What is Fondaparinux and what is its mechanism (how is it different from heparin)? |
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Definition
| A synthetic derivative of Heparin that only inhibits factor X through antithrombin |
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|
Term
| Why is Fondaparinux used/what are its indications? |
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Definition
| It is less likely to trigger heparin-induced thrombocytopenia |
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Term
| What are the Newer Antithrombin agents other than Warfarin and Fondaparinux? |
|
Definition
| Lepirudin, Bivalirudin, Argatroban, and Drotrecogin alfa |
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Term
| What is the major indication of giving Lepirudin? |
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Definition
| To treat patients with heparin-induced thrombocytopenia |
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|
Term
| What patients should not be given Lepirudin? |
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Definition
|
|
Term
| Lepirudin, Bivalirudin, and Argatroban inhibit what factors? |
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Definition
|
|
Term
| Drotrecogin alpha inhibits what factors? |
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Definition
|
|
Term
| What is the natural clot dissolver in the body? |
|
Definition
|
|
Term
| What drug class dissolves clots/emboli? |
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Definition
|
|
Term
| What are the Thrombolytic drugs? |
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Definition
| Streptokinase, Urokinase, t-PA: Alteplase |
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|
Term
| How does Streptokinase work? |
|
Definition
| Binds to plasminogen and induces conformational change to expose active sites |
|
|
Term
|
Definition
| It is a serine protease enzyme that Activates Plasminogen directly |
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|
Term
|
Definition
| High binding affinity for fibrin so it produces a clot-selective activation of plasminogen |
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|
Term
| What can be given for inhibition of thrombolytic drugs in case of overdose? |
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Definition
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|
Term
| When are thrombolytic drugs used? |
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Definition
| Severe pulmonary embolisms, DVTs, or arterial thromboembolisms |
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|
Term
| What drugs are used in conjunction with Thrombolytic drugs? |
|
Definition
| aspirin, beta-blockers, ACE inhibitors |
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|
Term
| What are some major contraindications for Thrombolytic therapy? |
|
Definition
| Recent surgery, hypertension, etc. |
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