Pharmacology of Anticoagulants, Antiplatelet Drugs, Coagulations & Thrombolytics Flashcards
What receptor is responsible for platelet-platelet binding?
GpIIb/IIIa
What class of anticlotting drugs is most useful in treating areterial thromboses?
Antiplatelets
True/False. All indirect thrombin inhibitors are approved for use during pregnancy.
False - only heparin is approved for pregnancy. Fondaparinux is not
These drugs are used to treat life-threatening pulmonary emboli, severe deep vein thrombosis, and acute ischemic stroke.
Recombinant tPA - alteplase, reteplace, teneteplase
What are the only classes of anticlotting drugs that dissolves existing clots?
Fibrinolytics and thrombolytics
True/False. Aspirin is indicated for primary prevention of heart attack or stroke.
False - no evidence supports aspirin as a primary preventative. Evidence does support use to prevent another heart attack or stroke
How does the MOA of Fondaparinux differ from heparin?
Both are indirect thrombin inhibitors, but Fondaparinux only enhances antithrombin’s ability to inactive Factor X and not thrombin directly
Antifibrinolytics inhibt the activity of plasminogen activators. What drugs belong to this class?
Aminocaproic acid, tranexamic acid
What clotting factors require Vitamin K for activation?
Factors II, VII, IX, X, Proteins C & S
What anticoagulants are direct Factor X inhibitors?
Rivaroxaban, apixaban, edoxaban
A PT test monitors the anticoagulation of what drug?
Warfarin
To what drug class do dipyridamole and cilostazol belong? What is their MOA?
Phosphodiesterase inhibitors - increase platelet cAMP, which inhibits platelet aggregation by modifying the ADP P2Y12 receptor
What is the antidote for heparin toxicity?
Protamine sulfate
What indirect thrombin inhibitors are contraindicated in patients with renal failure?
Low molecular weight heparin, fondaparinux
What are the classes of antiplatelet drugs?
COX inhibitors, Phosphodiesterase inhibitors, P2Y12 receptor blockers, GpIIb/IIIa receptor blockers, PAR antagonists
What is the reversal agent for dabigatran?
Idarucizumab
P2Y12 receptor blockers irreversibly inhibit ADP binding to the receptor. What drugs belong to this class?
Ticlopidine, clopidogrel, prasugrel
What molecules are released by active platelets to enhance aggregation and vasoconstriction?
ADP, TXA2, serotonin
This molecule naturally exists in the body to inhibit factors II, IX, X, XI, XII
Antithrombin III
What antiplatelet drugs act by blocking the GpIIb/IIIa receptors?
Abciximab, eptifibatide, tirofiban
True/False. Direct thrombin inhibitors bind free and clot-bound thrombin
True
What is the primary contraindication of warfarin?
Pregnancy
True/False. Warfarin is indicated to treat acute clots.
False - warfarin takes 4-5 days to become fully active. It is used as a preventative agent, not a curative agent
What drugs are used to treat heparin-induced thrombocytopenia?
Direct thrombin inhibitors (bivalirudin, argatroban, dabigatran)
This is a serious, but life-threatening ADR of heparin?
Heparin-induced thrombocytopenia
How do the MOAs of warfarin and direct factor X inhibitors differ?
Warfarin inhibits the Vitamin K epoxide reductase, which when active, activates certain clotting factors that go on to activate Factor X.
Direct Factor X inhibitors directly inhibit the activity of free and clot-bound Factor X
What is the MOA of aspirin?
Irreversibly inhibits COX 1 & 2 to decrease production of TXA2 (thromboxane)
What is the reversal agent for the direct factor X inhibitors?
Andexanet alpha
This antifibrinolytic is used to treat heavy menstrual bleeding.
Tranexamic acid
What is the MOA of heparin?
Heparin is an anticoagulant that indirectly inhibits thrombin by binding to antithrombin III and enhancing its functioning
This anticoagulant is a Vitamin K antagonist.
Warfarin
Clopidogrel is a prodrug that requires activation via liver metabolism. What enzyme is responsible for this transformation?
CYP2C19
What drugs are recombinant tPA?
Alteplase, reteplace, teneteplase
CYP2C9 is important in the metabolism of what anticoagulant?
Warfarin
These drugs reversibly inhibit COX 1 & 2 to inhibit TXA2 production.
NSAIDs
What are the three classes of anticlotting drugs?
Antiplatelets, anticoagulants and thrombolytics, fibrinolytics
What is the only antiplatelet drug that is a reversible antagonist of the P2Y12 receptor and its primary side effect?
Ticagrelor, shortness of breath
What test can be used to monitor heparin anticoagulation?
PTT
What are the direct thrombin inhibitors?
Hirudin, bivalirudin, argatroban, dabigatran
What primary ADR is associated with abciximab, eptifibatide, and tirofiban?
These are antiplatelet drugs -GpIIb/IIIa blockers. Primary ADR is thrombocytopenia
Early in administration, warfarin creates a hypercoagulable state that increases the risk of warfarin-induced skin necrosis due to clots. Explain the pathophysiology.
Warfarin inactivates protein C. Protein C functions as an inactivator of several clotting factors. Early inactivation of Protein C increases the risk of coagulation before warfarin’s anticoagulant effect is fully achieved
What is a contraindication for cilostazol use?
Congestive heart failure
What is the MOA of fibrinolytics?
Activate plasminogen to plasmin to breakdown fibrin clots
What is the MOA of vorapaxar?
Antiplatelet - competitive antagonist of the PAR receptor to prevent thrombin from binding platelets
What are the clinical indications for dabigatran?
Prevent venous thrombosis post-surgery, atrial fibrillation
This drug is used to prepare patients with hemophilia or vWF disease for elective surgery.
Desmopressin
True/False. Heparin only affects free thrombin and Factor X.
True - heparin has no effect on clot-bound thrombin or Factor X
This test is used to assess platelet functioning.
Bleeding time
This drug stabilizes and increases the activity of Factor VIII and vWF.
Desmopressin
