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34 Cards in this Set
- Front
- Back
Mechanism of heparin
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Catalyzes activation of antithrombin III, decr thrombin and Xa
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Clinical use of heparin
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Immediate anticoag for PE, stroke, acute coronary symptom, MI, DVT
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What lab test do you use when you are following heparin?
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PTT
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Is heparin safe to use in pregnancy?
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Yes (can't cross placenta)
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Toxicity of heparin
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Bleeding
Thrombocytopenia (HIT) Osteoperosis Drug drug interactions |
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What do you use for reversal of rapid heparanization?
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Protamine sulfate (positively charged molecule) acts by binding to negatively charged heparin
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Difference b/w low molecular weight heparins and older hepatins
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Act more on Xa
Have better bioavailability and 2-4x longer half life Can be administered subq without monitoring Not easily reversible |
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Heparin induced thrombocytopenia (HIT)
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Heparin binds to platelets causing autoantibody production that destroys platelets and overactivates remaining ones, resulting in thrombocytopenic, hypercoagulable state
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Lepirudin, bivalirudin
(a) mechanism (b) clinical use |
(a) directly inhibit thrombin
(b) used as an alternative therapy fro HIT patients |
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Warfarin (coumadin) mechanism
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Interferes with normal synthesis and gamma carboxylation of vitK dependent clooting factors (II, VII, IX, X, protein C, S)
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Which test is more affected by warfarin?
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PT (follow INR as well)
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Clinical use of warfarin
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Chronic anticoagulation
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Can you use warfarin in pregnancy?
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No-crosses placenta
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Toxicity of warfarin
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Bleeding
Teratogenic Skin/tissue necrosis Drug drug interactions |
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Alteplase mechanism
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t-PA derivative
Convert fibrin bound plasminogen, thus targeting clots |
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Urokinase mechanism
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Activates plasminogen to plasmin
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Streptokinase mechanism
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Activates plasminogen to plasmin
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Clinical use for thombolytics
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Early MI, early ischemic stroke
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Thrombolytics (give major examples)
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Streptokinase, urokinase, tPA (alteplase), APSAC (anistreplase)
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Mechanism of thrombolytics (in general)
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Directly or indirectly aid conversion of plasminogen to plasmin which cleaves thrombin and fibrin clots
Incr PT and incr PTT No change in platelet count |
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Toxicity of thrombolytics
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Bleeding
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Thrombolytics contraindicated in who?
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Active bleeding
Hx of intracranial bleed Recent surgery Known bleeding disease Severe HTN |
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Treatment for thromblytic toxicity
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Aminocaproid acid (inhibits fibrinolysis)
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Aspirin mechanism of action
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Acetylates and irreversibly inhibits COX 1 and 2 preventing conversion of arachidonic acid to thromboxane A2
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Aspirin
PT PTT Bleeding time |
PT/PTT don't change
Bleeding time incr |
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Clinical use of aspirin
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Antipyretic
Analgesic Anti inflammatory Antiplatelet drug |
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Toxicity of aspirin
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Gastric ulcers
Bleeding Hyperventilation Reye's syndrome (in children) Tinnitus (CN VIII) |
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Clopidogrel mechanism
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Inhibit platelet aggregation by blocking ADP receptors; inhibit fibrinogen binding by preventing glycoprotein Iib/IIIa expression
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Clinical use of clopidogrel
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Acute coronary syndrome
Decr incidence or recurrence of thrombotic stroke in coronary stent |
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Ticlopidine mechanism
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Inhibit platelet aggregation by blocking ADP receptors; inhibit fibrinogen binding by preventing glycoprotein Iib/IIIa expression
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Ticlopidine toxicity
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Neutropenia
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Abciximab mechanism
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Monoclonal Ab that binds to glycoprotein receptor Iib/IIIa on activated platelets, preventing aggregation
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Clinical use of abciximab
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Acute coronary syndromes; percutaneous transluminal coronary angioplasty
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Toxicity of abciximab
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Bleeding, thrombocytopenia
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