Anticoagulation Flashcards
warfarin (Coumadin)
Inhibits activation of clotting factors in liver that depend on Vitamin K for synthesis (factors II, VII, IX, and X and coagulation inhibitor proteins C and S)
Does not affect function of existing clotting factors, and has no effect on existing clots
Indications:
Prevention and treatment of venous thrombosis, Systemic embolism, PE
Atrial Fibrillation
Half life: 36 to 42 hours
dabigatran (Pradaxa)
Binds to active site of thrombin, Prevents generation of additional thrombin, Decreases platelet activation
Prevents conversion of fibrinogen to fibrin
Directly inhibits free and clot-bound thrombin
Indication: Reduction of risk of stroke and systemic embolism in non-valvular atrial fibrillation
Peak: 1 hour
Half life: 12-17 hrs
Unfractionated Heparin
Inhibits reactions that lead to clotting without altering concentration of normal clotting factors
Inactivates thrombin, prevents conversion of fibrinogen to fibrin
Preventive of post-op thromboembolism
Onset: 20-60 min
Peak: 1h
Half Life: 1-3h (dose dependent)
Monitor aPTT every 6 hours until stable, then every 12 hours
Low Molecular Weight Heparin
Enoxaparin (Lovenox), dalterparin (Fragmin), tinzaparin (Innohep)
Response is predictable, do not need monitoring aPTT. May check anti-Xa levels in patients with renal dysfunction, morbid obesity, pregnancy. Check CBC periodically.
Contraindications: active major bleeding, indwelling epidural catheters, hypersensitivity to pork products, HIT associated with LMWH
Factor Xa Inhibitors
Fondaparinux (Arixtra) - subcutaneous
Rivaroxaban (Xarelto) – oral
Antiplatelet Agents
Inhibit platelet aggregation (various MOAs)
Aspirin
Aspirin + dipyridamole (Aggrenox)
Clopidigrel (Plavix)
Ticlopidine (Ticlid)
Noncardioembolic ischemic stroke/TIA
Secondary Stroke Prevention
Clopidogrel
or ASA/dypiridamole preferred
Ischemic stroke/TIA and AF
Secondary Stroke Prevention
Oral anticoagulation with dabigatran preferred
