Antithrombotic and Fibrinolytics Flashcards
1
Q
Anti-coagulants drugs
A
- Prevents thrombus formation
2
Q
Anti-platelet drugs
A
Prevents platelet aggregation
3
Q
Fibrinolytics
A
- Clot retraction
4
Q
Warfarin
A
- Vitamin K antagonist
5
Q
Apixaban, Edoxaban and Rivaroxaban
A
- Direct oral anticoagulant and reversible factor Xa
6
Q
Dabigatran
A
- Reversible inhibitor of thrombin
7
Q
Function of Warfarin
A
- Coagulation factor (II, VII, IX, X) undergoes y - carboxylation to get activated
- y-carboxylation requires the reduced vitamin K which is converted into oxidized vit K
- Vitamin K reductase enzyme inhibit by Warfarin restores the reduced vitamin K
8
Q
Warfarin characteristics
A
- Slow onset
- Inhibit vit K-dependent protein C which is natural anti-coagulant causing pro-coagulant before anticoagulant effect
- Excess administration can overcome warfarin binding to reductase enzyme
8
Q
Pharmacokinetics of Warfarin
A
- 99% bound to plasma albumin also metabolized in liver eliminated in urine
9
Q
Drug interaction of Warfarin
A
- Warfarin causes breakdown antibiotics and azoles which and H2 receptor antagonist
- NSAIDs potentiate the effect of warfarin
- Antibiotics kill gut flora and vit K increase effect of warfarin
10
Q
Dabigatran
A
- Reversible inhibitor of free thrombin
- Fibrin-bound thrombin and thrombin induced platelet aggregation
11
Q
Apixaban
A
- Direct and reversible inhibitors of factor Xa
- Inhibition prevent thrombotic process
12
Q
Heparin
A
- Anti-thrombin and heparin complex bind inhibit thrombin mediated platelet activation
13
Q
Externally administered Heparin
A
- Unfractionated heparin larger molecule and low molecular weight heparin both replicate effect of normal heparin
- Inhibitor factors of Xa (compliment anti-coagulant effect)
14
Q
Adverse effects of Heparin : Hemorrhage
A
- Caused when there is low levels of unfractionated or low MW heparin
- Reverse effects by using protamine sulphate reverse low MW
15
Q
Heparin induced thrombocytopenia
A
- Immune mediated low levels of thrombosis
- Reduction of platelet count
- Give danaparoid anticoagulant more affinity to factor Xa
16
Q
Hyperkalemia from heparin
A
- Inhibition of aldosterone secretion by unfractionated or low MW heparin
- Patients with diabetes chronic renal failure raised potassium levels more susceptible
17
Q
Argatroban
A
- Direct thrombin inhibitor used in hospital
18
Q
Epopresentol
A
- Prostacyclin inhibits platelet aggregation during renal analysis
19
Q
Fibrinolytics
A
- Plasminogen plasma protein trapped in clot
- Plasmin digest fibrin dissolution of clot
- Mediated by TPA (Tissue plasminogen activator)
19
Q
Streptokinase
A
- Natural bacterial toxin patient develops antibodies against toxin
- Produces anaphylactic reactions
- Replaced by TPA (Alteplase)
20
Q
ADP receptor antagonist
A
- Clopidogrel a prodrug irreversibly inhibits ATP binding to P2Y12 reducing platelet aggregation
21
Q
Ticagrelor
A
- Directly acts on P2Y12 and reversibly inhibits P2Y12
- Reduction of ADP mediated platelet aggregation non-competitive
21
Q
Clopidogrel therapy
A
- Prodrug that needs to be metabolised by CYP2C19 to be activated
- Those carrying genetic variation may have low level CYP2C19 cannot metabolise
22
Q
Aspirin
A
- NSAID blocks COX pathways inhibits prostaglandin release and platelet mediated prostacyclin release and platelet mediated thromboxane decrease platelet aggregation
23
Q
Glycoprotein IIb/IIIa inhibitors
A
- Prevent platelet aggregation by blocking the binding of fibrinogen to receptors on platelets
24
Q
Abciximab
A
- Monoclonal antibody which binds to
glycoprotein IIb/IIIa receptors - Added to aspirin and heparin to prevent ischemia complications for patients undergoing coronary intervention
25
Q
Eptifibatide and tirofiban
A
- Used to prevent early MI for patients with angina unstable
