Hematology and oncology Flashcards
Heparin mechanism
Activates antithrombin
Decreases thrombin and factor Xa. Short 1/2 life
Heparin induced thrombocytopenia
IgG antibodies against heparin bound platelet factor 4 (PF4) that activates platelets leading to thrombosis and thrombocytopenia
Argatroban
Inhibits thrombin directly
Use if patient has HIT
Bivalirudin
Related to hirudin (the anticoagulant in leeches)
Inhibits thrombin directly
Use if patient has HIT
Dabigatran
Inhibits thrombin directly
Use if patient has HIT
Warfarin mechanism
Long half-life.
Inhibits g-carboxylation of vit. K factors (2, 7, 9, 10, Protein C and S
VKORC1 gene mutation effects metabolism
Extrinsic pathway, ^ PT.
Warfarin use
Chronic anticoagulation: venous thromboembolism prophylasix and prevention of stroke in atrial fib.
Do NOT use in pregnancy (cross placenta)
Follow PT/INR
Warfarin toxicity
Bleeding, teratogen, skin/tissue necrosis, drug interactions Transient hypercoaguability (Pro. C/S have shorter half lives) Antidote: Fresh frozen plasma-rapid reversal Vitamin K- longer reversal
Rivaroxaban
Inhibits Factor Xa Rx/prophylaxis for DVT and PE Stroke prophylaxis in patient with atrial fibrillation Does not require coagulation monitoring Tox: bleeding
Apixaban
Inhibits Factor Xa
Stroke prophylaxis in patients with atrial fibrillation
Does not require coagulation monitoring
Tox: bleeding
Thrombolytics
Ateplase (tPA)
reteplase (rPA)
streptokinase
Tenecteplase (TNK-tPA)
Directly or indirectly aid conversion of plasminogen to plasmin, which cleaves thrombin and fibrin clots
^PT and PTT with no change in platelet count
Heparin use
Immediate anticoag. for PE and acute coronary syndrome, MI , DVT, safe during pregnancy
Heparin toxicity
Bleeding, HIT, osteoporosis, drug interactions.
Heparin antidote
Protamine sulfate
