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28 Cards in this Set
- Front
- Back
Three treatment strategies to inhibit coagulation
|
thrombolytics
anticoagulants anti-platelets |
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3 things that thrombolytics drugs are used for
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acute MI
PE DVT |
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Within how many hours can you use a thrombolytic?
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6 hours for MI
3 hours for stroke |
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How do tPA's work
(tissue plasminogen activator) |
-at physiological concentrations they are inhibited by Plasminogen Activator Inhibitor (PAI).
-at pharmacological concentrations they over come the PAI |
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What are the Thrombolytics?
|
Streptokinase
Urokinase Alteplase Reteplase Tenecteplase ("plase" = tPA) |
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Streptokinase
|
-causes conformational change in plasminogen so that is can convert easier to plasmin and lyse the clot
-isolated from bacteria |
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Urokinase
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-directly converts plasminogen to plasmin
-no anaphylaxis like in streptokinase |
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mechanism of tPA's
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1) selective activation of plasminogen when it is bound to fibrin
2) this localizes the fibrolysis to the area of the thrombus |
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Anticoagulant Drugs?
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Heparin - inc ATIII
Hirudin - DTI Warfarin - dec Vit K dependents Drotracogin Alfa - aProtein C |
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Drugs that activate anticlotting factors
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Heparin
Fondaparinux (pentasacchride) Dalteparin (LMW) Enoxaparin (LMW) |
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Heparin mechanism
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-binds to ATIII to complex with activated factors of the intrinsic pathway
-coats blood vessel wall to decrease platelet binding and increase its permeabililty |
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Pharmacokinetics of Heparin family?
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-adjust dose to double PTT
-doesn't cross placenta -instantaneous |
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HMW vs LMW Heparin family drugs
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HMW: Xa, more predictable, decrease dose
LMW: IIa, less inhibition, more SE, less plasma protein bound, antidote not as effective |
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Adverse effects of Heparins
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-bleeding (duh)
-anaphylaxis (duh) -HIT (antibody mediated thrombocytopenia) |
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Protamine Sulfate
|
-basic peptide that forms an ionic bond with heparin to inactivate it
-doesn't work with FONDAPARINUX |
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Direct Thrombi Inhibitors (DTI's)
(name the drugs) |
Bivalirudin
Hirudin Lepirudin Argatroban |
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DTIs
(mechanism, metabolism) |
-interact directly with thrombin, there is no HIT
"Rudins" bind irreversible, kidney "Agratroban bind reversible, liver -no reversal agents |
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When do you want to use DTI's
|
-patients with HIT
-Bivalirudin for angioplasty |
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Inhibitor of Zymogen synthesis
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Warfarin (Coumadin)
|
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Mechanism of Warfarin
|
-inhibits epoxide reductase which recycles Vit K
-affects factors II, VII, IX and X -affects Protein C and S (side effects) |
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Pharmacokinetics of Warfarin
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-narrow TI
-racemic mixture where S is the active enantiomer -S is metabolized by Cyp2C9 |
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Gene mutations involved with Warfarin
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Cyp2C9 (slows metabolism)
VKOR (decreases effectiveness) Factor V Leiden (can't stop cascade) |
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What is another name for the Warfarin drug?
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Rodenticides
|
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Three uses of Warfarin
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DVT
MI AFIB |
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*IMPORTANT*
3 general features of Warfarin |
-narrow therapeutic index
-99% plasma protein bound -elminated in the liver by Cyt P450 |
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Things that increase the interactions of Warfarin
|
1) inhibit CYT P450
2)Decrease Plasma Protein Binding 3) Decrease plaetelet/clotting factors 4)Decrease Vit K availability |
|
Phytonadione
(three purposes) |
Vitamin K1
1) prevents hemorrhagic disorders in new borns 2) corrects Vit K deficiency 3) Warfarin overdose |
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What can you give to counter act Warfarin?
|
Vit K
fresh-frozen plasma |