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57 Cards in this Set
- Front
- Back
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What are common sites of intravascular thrombus formation?
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coronary artery, cerebral artery, peripheral artery, deep vein
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What can cause thrombous?
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abnormal vascular surface, stasis of blood, activation of coagulation cascade/platlet aggregation, failure of endogenous anticoagulant mechanisms, inadequate fibrinolytic response
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What degrades fibrin?
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plasmin
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What degrades fibrinogen?
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plasmin
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What holds platelets together in aggregate?
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fibrinogen
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What do kringle structures on plasminogen activators do?
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bind fibrin in clot, target activity to target site
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Where is the major source of plasminogen?
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liver
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From where does streptokinase come?
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non-enzymatic protein from group C strep
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How was t-PA created?
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human recombinant serine protease
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How was Reteplase made?
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genetically engineered derivative of t-PA, second kringle domain and protease domain
not glycosylated |
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What are the indications for thrombolytic therapy in acute MI?
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chest pain consistent with MI, ST elevation, new LBBB, <6h since onset of symptoms, larger area of potential infarct
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What are typical uses for thrombosis?
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acute MI
acute ischemic stroke acute arterial thormbo-occlusion mainstem pulmonary embolism thrombosed prosthetic valves thrombosed AV shunts |
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What is the most important thing about treating an MI?
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more important that a patient receives an IV thrombolytic than which one you give
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What does thrombin time measure?
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persistant lytic state, prolonged by heparin
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What does PTT measure?
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persistent lytic state
heparin prolongs |
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What does Reptilase time measure?
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persistent lytic state in heparinized patients
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What does fibrinogen measure?
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guide to therapy with cryoprecipitate
check to assure adequate repletion, clotting rate assay |
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What does bleeding time measure?
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persistent bleeding despite cryoprecipitate and FFP
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What does fibrinogen degradation measure?
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elevation confirms lytic state
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What do you do with life-threatening bleeding?
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stop thrombolytics/anticoagulants, check thrombin time, fibrinogen, bleeding time, administer cryoprecipitate/platelets
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What patients should you not give thrombolytics to?
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thin, elderly female
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What causes the initial hemostatic plug at sites of vascular injury?
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platelets adhere to damaged tissue
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What do stimulated platelets produce?
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thromboxane A2
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What is the final common pathway of platelet activation?
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expression of activated form of glycoprotein IIb/IIIa (fibrinogen) receptor
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What do platelets do?
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provide a surface for localization and interaction of coagulation factors which ultimately lead to formation of fibrin clot
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What does thrombosis of a blood vessel lead to?
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ischemia/necrosis of tissue supplied by affected vascular structure
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What is the major cycooxygenase product of endothelial cells?
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PGI2
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What does prostacyclin do?
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vasodilator, anti-platelet aggregating prostanoid, but can be synthesized new from endothelial cells
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What's up with enteric coated aspirin?
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absorption is sometimes incomplete, can produce fewer GI problems
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What are the doses of aspirin for antiplatelet effects?
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low doses preferentially affect platelets
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What class of drug is Ticlopidine?
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thienopyridine
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What class of drug is Prasugrel?
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thienopyridine
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What is Ticlopidine's MOA?
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inhibits platelet activity by inhibiting ADP-induced platelet activation, glycoprotein IIb/IIIa receptor, von Willebrand factor
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What is Prasugrel's MOA?
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inhibits platelet activity by inhibiting ADP-induced platelet activation, glycoprotein IIb/IIIa receptor, von Willebrand factor
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What is Ticlopidine's bioavailability?
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improved with food, decreased by antacids, increased in elderly patients
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How is Ticlopidine metabolized?
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by the liver into active drug, CYP450 dependent
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How is Prasugrel metabolized?
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by the liver into active drug, CYP450 dependent
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In which patients is Ticlopidine contraindicated?
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with severe helpatic or renal impairment
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When is the max antiplatelet activity of Ticlopidine?
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5-10 days after onset
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When is the max antiplatelet activity of Prasugrel?
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5-10 days after onset
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What are the drug interactions of Ticlopidine?
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CYP3A4 inhibitors reduce bioactivation
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What are the drug interactions of Prasugrel?
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CYP3A4 inhibitors reduce bioactivation
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What are the side effects of Ticlopidine?
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bleeding, nausea, diarrhea, neutropenia, hepatic dysfunction, epistaxis, ecchymoses, menorrhagia, thrombocytopenia, TTP, cholesterol increased
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What are the side effects of Prasugrel?
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bleeding, nausea, diarrhea, CYP450 stuff, hepatic dysfunction, epistaxis, ecchymoses, menorrhagia, thrombocytopenia, TTP, cholesterol increased
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For what would you give Ticlopidine?
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reduce stroke risk, CAD, microaneurysms, retinopathy in DM, peripheral vascular disease
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For what would you give Prasugrel?
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reduce stroke risk, CAD, microaneurysms, retinopathy in DM, peripheral vascular disease
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What is protamine?
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drug that binds heparin to inactivate it, intrinsic anticoagulant effects
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What is the danger of protamine?
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allergic toxicity, must be administered slowly becasue of risk of dyspnea, flushing, bradycardia, hypotension, anaphylaxis
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What kind of drug is Fondaparinux?
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pentasaccharide
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What does Fondaparinux do?
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Factor Xa inhibitor, binds to antithrombin and increases inhibition of Factor Xa, indirect Factor Xa inhibitor, like LMWH
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Why would you give Fondaparinux?
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prophylaxis of DVT in ortho surgery, ACS
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How is Fondaparinux cleared?
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kidney
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What kind of drug is Lepirudin?
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direct thrombin inhibitor
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What is Lepirudin's MOA?
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inhibits active site pocket and fibrinogen binding site of free/clot-bound thrombin
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What are the pharmacokinetics of Lepiruidin?
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2 compartments, administered IV
renal clearance and degradation |
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To whom should you not give Lepiruidin?
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patients with kidney problems
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To whom should you give Lepiruidin?
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patients with heparin-induced thrombocytopenia
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