Pharmacology-anticoagulant therapy Flashcards
Indications for heparin
PE, ACS, MI, DVT
What anticoagulation test is used to monitor heparin therapy?
PTT
Why is heparin safe to use during pregnancy?
Does not cross placenta
What is the treatment for rapid reversal of HIT?
Protamine sulfate
What do low molecular weight heparins target predominantly?
Factor Xa
What is the only heparin drug that only targets factor Xa?
Fondaparinux
What is the advantage of LMWH over unfractioned heparin?
Better bioavailability and 2-4x longer 1/2 life
Can be given subq without monitoring
What is a disadvantage of LMWH over unfractioned heparin
Cannot be easily reversed
Development of IgG antibodies against heparin-bound platelet factor 4
Heparin induced thrombocytopenia (HIT)
What is a complication of using heparin in susceptible individuals?
Development of HIT
What action does the antibody-heparin-PF4 complex have on the body?
Activates platelets causing thrombosis and thrombocytopenia
What is the only oral direct thrombin inhibitor?
Dabigatran
What is the direct thrombin inhibitor that is related to the anticoagulant used by leeches?
Bivalirudin
What are the direct thrombin inhibitors?
Bivalirudin, Argatroban, and Dabigatran
What is the mechanism of Bivalirudin, Argatroban, and Dabigatran?
Directly inhibit thrombin activity
What drug can be used to reverse Dabigatran effects?
Idarucizumab
What can be used if no reversal agents are available for Dabigatran?
Tranexamic acid
What coagulation pathway is affected by warfarin?
Extrinsic pathway
What is the effect of warfarin on PT?
Increases PT
What anticoagulation test is used to monitor warfarin therapy?
PT/INR
What can be given to rapidly reverse the effects of warfarin?
Fresh frozen plasma or PCC
What can be done to prevent the transient hypercoagulable state and risk of recurrent venous thromboembolism and skin/tissue necrosis caused by warfarin?
Give heparin bridge
What is the cause of early transient hypercoagulability with warfarin use?
Shorter 1/2 lives of Protein C and S
What is the site of action of warfarin?
Liver
What is the route of administration for warfarin?
Oral
What is the route of administration for heparin?
Parenteral (IV or SC)
What are the direct factor Xa inhibitors?
Apixaban and Rivaroxaban
What is the disadvantage of direct factor Xa inhibitors?
Bleeding is not easily reversed
Indications for direct factor Xa inhibitors
DVT, PE and stroke prophylaxis for a-fib
What is an advantage of oral direct factor Xa inhibitors?
Do not require lab monitoring
What are the thrombolytics?
Alteplase (tPA), Reteplase (rPA), tenecteplase (TNK-tPA) and streptokinase
What is the effect of thrombolytics on platelet count?
No effect
What is the mechanism of thrombolytics?
Convert plasminogen to plasmin
What is the effect of cleaving plasminogen to plasmin using thrombolytics?
Cleaves thrombin and fibrin clots
Indications for thrombolytics?
Early MI, ischemic stroke and severe PE
What are the ADP receptor inhibitors?
Clopidogrel, Prasugrel, Ticagrelor, and Ticlopidine
Mechanism of ADP receptor inhibitors Clopidogrel, Prasugrel, Ticagrelor, and Ticlopidine
Stop platelet aggregation by irreversibly binding ADP receptor
What is the effect of binding ADP receptor with Clopidogrel, Prasugrel, Ticagrelor, and Ticlopidine
Prevents expression of GpIIb/IIIa on platelet surface
Indications for ADP receptor inhibitors
ACS, coronary stenting, decrease thrombotic strokes
PDE inhibitors
Cilostazol and dipyrdamole
What is the effect of PDE inhibitors Cilostazol and dipyrdamole?
Increase cAMP in platelets stopping platelet aggregation; also vasodilate
Indications for PDE inhibitors Cilostazol and dipyrdamole
Claudication, coronary vasodilation, prevent stroke or TIAs
What drug is usually given with PDE inhibitors Cilostazol and dipyrdamole to prevent stroke or TIAs?
Aspirin
What are side effects of PDE inhibitors Cilostazol and dipyrdamole?
Nausea, headache, facial flushing, hypotension, abdominal pain
What are the GpIIb/IIIa inhibitors?
Abciximab, Eptifibatide, Tirofiban
What is the effect of GpIIb/IIIa inhibitors Abciximab, Eptifibatide, and Tirofiban?
Prevent platelet aggregation
Which GpIIb/IIIa inhibitors is made from monoclonal antibody Fab fragments?
Abciximab
Indications for GpIIb/IIIa inhibitors Abciximab, Eptifibatide, and Tirofiban
Unstable angina and percutaneous coronary intervention
Side effects of GpIIb/IIIa inhibitors Abciximab, Eptifibatide, and Tirofiban
Bleeding and thrombocytopenia