Hematology Pharm Flashcards
MoA of Heparin
Lowers the ACTIVITY of thrombin and factor Xa. Short half-life.
Used during pregnancy (does not cross placenta)?
Heparin or Warfarin?
Heparin
What do you have to monitor when on Heparin?
PTT
ADR of Heparin
Bleeding, thrombocytopenia (HIT), osteoporosis, drug-drug interactions
Why does Protamine Sulfate work as a Heparin Antidote?
positively charged molecule that binds negatively charged heparin
name the LMW Heparins
enoxaparin, dalteparin and fondaparinux
Difference between LMWH and Heparin? (5)
Low-molecular-weight heparins act more on factor Xa
have better bioavailability and 2–4 times longer half-life
can be administered subcutaneously
without laboratory monitoring
Not easily reversible.
Pathogenesis of HIT
development of IgG antibodies against heparin- bound platelet factor 4 (PF4). Antibody-heparin-PF4 complex activates platelets -> thrombosis and thrombocytopenia.
Name the Direct Thrombin inhibitors
Bivalirudin, argatroban, dabigatran
What hematological drug is related to hirudin, the anticoagulant used by leeches?
Bivalirudin
MoA of Bivalirudin and the GATRs
Directly inhibits activity of free and clot-associated thrombin.
What drugs do you use in place of heparin during HIT?
Direct Thrombin Inhibitors
ADR of Direct Thrombin Inhibitors?
bleeding with no reversal agent
What can you attempt to use to prevent ADR of Direct Thrombin Inhibitors?
Activated Prothrombin Complex Concentrates (PCC)
and Tranexamic Acid (fibrinolytic)
Warfarin inhibits what process?
gamma carboxylation of Vitamin K Dependent Clotting factors
What are the Vit K dependent clotting factors?
II, VII, IX, X, Protein C and S
Warfarin effects what pathway and prolongs what test?
Extrinsic Pathway and increases PT
What polymorphism affects metabolism of Warfarin?
VKORC1
Vit K Epoxide Reductase Complex
Pathogenesis of early, transient hypercoaguability of Warfarin?
Proteins C and S have shorter half-lives than clotting factors II, VII, IX, and X, resulting in early transient hypercoagulability with warfarin use.
Pathogenesis of warfarin-related skin necrosis?
Skin/ tissue necrosis within rst few days of large doses believed to be due to small vessel microthromboses.
Explain Heparin Bridging
heparin frequently used when starting warfarin. Heparin’s activation of antithrombin enables anticoagulation during initial, transient hypercoagulable state caused by warfarin. Initial heparin therapy reduces risk of recurrent venous thromboembolism and skin/tissue necrosis.
MoA of Apixaban, rivaroxaban and ADR
Bind to and directly inhibit factor Xa.
Bleeding
rivaroxaban clinical use
Treatment and prophylaxis for DVT
MoA of Alteplase (tPA), reteplase (rPA), streptokinase, tenecteplase (TNK-tPA)
Directly or indirectly aid conversion of plasminogen to plasmin, which cleaves thrombin and brin
clots.
