Thrombolytics, Anticoagulants, Anti-platelet drugs Flashcards
High doses of Aspirin can see this neurologic side effect:
Tinnitus
Mechanism of action of Aspirin
Irreversible COX inhibitor, prevents thromboxane release
If given at a low dose, aspirin affects _____, if given at a high dose, aspirin affects ______.
Platelets, endothelial cells
What are the three ADP receptor antagonists?
Clopidogrel
Prasugrel
Ticlopidine
Which of the three ADP receptor antagonists has the most side effects?
Ticlopidine
Clopidogrel requires activation by _______
CYP2C19
What is a very serious side effect of Ticlopidine use?
Thrombotic thrombocytopenic purpura
What is the mechanism of action of Dipyridamol?
Inhibits phosphodiesterase, results in increased cAMP, decrease platelet activation
What is another effect of dipyridamol for vessels?
vasodilation
What is the mechanism of action of Abciximab?
Antibody that blocks GPIIb/IIIa, prevents binding of fibrinogen and vW factor to platelets
What is the mechanism of action of Eptifibatide and Tirofiban? What’s different about them?
Antagonists of GPIIa/IIIb
Eptifibatide is an analogue of fibrinogen, tirofiban is not a peptide
What is a major drawback to GPIIa/IIIb inhibitors?
Given IV
What are the four direct heparin inhibitors?
Lepirudin
Bivalirudin
Argatroban
Dabigatran etexylate
What are the three indirect thrombin inhibitors?
Heparin
LMW heparin
Fondaparinux
What do direct thrombin inhibitors do?
…directly inhibit the thrombin enzyme.
What do indirect thrombin inhibitors do?
Interact with antithrombin in its inactivation of factor Xa (which activates thrombin)
Also accelerate antithrombin’s deactivation of thrombin
How does the mechanism of action of Heparin and fondaparinux differ?
Heparin takes out both factor Xa and thrombin
Fondaparinux only takes out Xa
What are some side effects for heparin?
Bleeding
Heparin induced thrombocytopenia
What drug is used to reverse activity of heparin?
Protamine
What is the mechanism of action of warfarin?
Blocks synthesis of vitamin K dependent clotting factors
What conversion of vitamin K does warfarin affect?
vitamin K epoxide to vitamin K hydroquinone
What factors are affected by warfarin use?
factors II, VII, IX, X, and protein C
What is unique about warfarin’s effects on protein C?
Its effects initially cause a hyper-coagulable state
What do you give along with warfarin at first administration?
heparin
What are the side effects of Warfarin?
Bleeding
Flatulence and diarrhea
cutaneous necrosis
chondrodysplasia punctata
What is the more active enantiomer of warfarin?
S
What are the S and R enantiomers of warfarin metabolized by in the liver?
R: CYP 1A1, 1A2, 3A4
S: CYP 2C39
Which drug that we’ve been learning about has a crazy long list of drug/drug interactions?
Warfarin
Pharmacokinetic drug interactions of oral anticoagulants are primarily due to the following three things:
Enzyme induction
Enzyme inhibition
Reduced plasma protein binding
Pharmacodynamic drug/drug interactions for oral anticoagulants are primarily due to these three things:
Reduced clotting factor synthesis
Competitive antagonism with Vitamin K
Hereditary resistance to oral anticoag
What drug should be given to antidote overdose of warfarin?
Phytonadione (Vitamin K from plants)
What does tPA stand for and what three are we supposed to know?
Tissue plasminogen activators.
Alteplase
Reteplase
Tenecteplase
What drawback does the tPA drug have?
Given IV, Cost
What are the tPA’s particularly good for treating?
stroke
