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29 Cards in this Set
- Front
- Back
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Drugs that inhibit platelet activation act primarily where?
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Arteries
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Drugs that inhibit thrombin and fibrin act primarily where?
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Veins
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What is released with platele activation
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ADP, Serotoning and TXA2
Leads to conformation change in GP IIb/IIIa to bind fibrinogen (RGD) |
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Aspirin (ASA)
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Irreversible inhibits platelet TXA2 production (which triggers plately aggregation)
SE GI distress, ulcer and bleeding |
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Dipyridamole
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Increase adenosine which increases cAMP levels and inhibits PDE (which breaks down cAMP)
Potentiates aspirin |
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Acts increase adenosine and inhibit PDE
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Dipyridamole
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Clopidogrel (Plavix)
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Blocks ADP (which aggregates platelets) Takes 4-6 days to take effect. Safe, and more effective than aspirin
CI in active bleeders |
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ADP inhibitor
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Clopidogrel (Plavix)
4-7 days to take effects |
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Abciximab
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mAb that blocks GP IIb/IIIa
adjunct to heparin and aspirin for the usual + PCI |
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Eptifibatide
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Synthetic peptide GP IIb/IIIa inhibitor
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Tirofiban
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synthetic non-peptide GP IIb/IIIa inhibitor
Reduce MI death 22% when used with heparin and aspirin |
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Three GP IIb/IIIa inhibitors
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Abciximabe
Eptifibatide Tirofiban |
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MOA heparin
Measure its effects |
binds antithrombin III to block factor Xa and thrombin (IIa)
PTT |
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UFH vs LMWH
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LMWH more specific for Xa, twice daily dosing safely and less incidence of HIT
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Tx for HIT
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protamine sulfate plus switch to direct thrombin inhibitor
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lepirudin
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Direct thrombin inhibitor, originially for leeches. May develop antibodies to it which decrease renal clearance
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Bivalirudin
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VERY expensive direct thrombin inhibitor with short half life (25 mins) for coronary angioplast in pts with prior HIT
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Argatroban
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Inhibits free and fibirin bound thrombin...excreted via liver
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Three direct thrombin inhibitors
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Lepirudin
Bilvalirudin Argatroban |
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Warfarin MOA
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competitive inhibitor of vit K. Vit K needed for carboxylation of factor VII, IX, X, II and protein C. Inhibits synthesis, so it needs days for already synthesized factors to be removed
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Risk factors for hemorrhage on warfarin
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Prior history
Cigarette smoking Renal insufficieny Anemia HTn |
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Contraindication for warfarin
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Preganacy
Active bleeding |
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Streptokinase
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complexes with plasminogen to convert other plasminogen to plasmin. Not selective, increased risk of bleed
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Problems with streptokinase
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Not selective for fibrin and resistant to antiplasmin so can cause massive thrombolysis. Also, pt may have preformed Ab's from Strep infection
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t-PA - Alteplase
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normal t-PA that converts plasminogen and overwhelms plasminogen activator inhibitor causing quick thrombolysis.
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t1/2 for t-PA
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3 minutes and rapid liver clearance
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Reteplase
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Lower fibrin affinity and longer half life than t-PA. Can be given in two bolus injections
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Tenecteplase
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Mutated t-PA for longer half life, high specificity for fibrin bound plasminogen. Given in 1 daily bolus
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Fibrinolytics
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Streptokinase
t-PA Reteplase Tenecteplase |
