1What is the primary goal of anticoagulant drugs?
To prevent the formation of blood clots (thrombi) or to prevent their extension
2Name the two main categories of parenteral (injectable) anticoagulants.
Unfractionated Heparin (UFH) and Low Molecular Weight Heparin (LMWH)
3What is the mechanism of action for Heparin?
It potentiates the action of Antithrombin III, which inactivates clotting factors, especially Thrombin (Factor \text{IIa}) and Factor \text{Xa}
4What lab test is used to monitor Unfractionated Heparin (UFH) therapy?
Activated Partial Thromboplastin Time (\text{aPTT})
5What is the antidote used to reverse the effects of an overdose of Heparin?
Protamine Sulfate
6Name the main oral anticoagulant drug that acts as a Vitamin K antagonist.
Warfarin
7What is the mechanism of action for Warfarin?
It blocks the enzyme \text{Vitamin K} Epoxide Reductase, preventing the synthesis of active \text{II}, \text{VII}, \text{IX}, and \text{X} clotting factors
8What lab test is used to monitor Warfarin therapy?
Prothrombin Time (\text{PT}) standardized as the International Normalized Ratio (INR)
9Name a drug classified as a Direct Factor \text{Xa} Inhibitor (a type of DOAC/NOAC).
Rivaroxaban (or Apixaban, Edoxaban)
10Name a drug classified as a Direct Thrombin Inhibitor (a type of DOAC/NOAC).
Dabigatran
11What is a key advantage of Direct Oral Anticoagulants (\text{DOACs}), like Apixaban, over Warfarin?
They have a predictable anticoagulant effect and do not require routine blood test monitoring (like \text{INR})
12What serious adverse effect is associated with Heparin therapy (especially UFH)?
Heparin-Induced Thrombocytopenia (\text{HIT})
13What is the classification of the drug Enoxaparin?
Low Molecular Weight Heparin (\text{LMWH})
14What is the antidote used to reverse the effect of Warfarin overdose?
Vitamin K (Phytomenadione)
15What is the major risk common to all anticoagulant drugs?
Increased risk of bleeding (hemorrhage)
16Which type of heparin has a more selective effect on inhibiting Factor \text{Xa} over Thrombin (\text{IIa})?
Low Molecular Weight Heparin (\text{LMWH})
17What is the primary mechanism of action for Unfractionated Heparin (UFH)?
It potentiates Antithrombin III, leading to the inactivation of Thrombin (\text{Factor IIa}) and \text{Factor Xa}
18How does Warfarin exert its anticoagulant effect?
It blocks the enzyme \text{Vitamin K} Epoxide Reductase, preventing the synthesis of active \text{II}, \text{VII}, \text{IX}, and \text{X} clotting factors
19What is the primary target of action for drugs like Rivaroxaban and Apixaban?
They directly inhibit \text{Factor Xa}
20What is the mechanism of action for Dabigatran?
It is a Direct Thrombin Inhibitor (DTI), binding directly to and inhibiting free and clot-bound Thrombin (\text{Factor IIa})
21How does Low Molecular Weight Heparin (LMWH), like Enoxaparin, primarily function?
It selectively inhibits \text{Factor Xa} via Antithrombin III, with less effect on Thrombin (\text{IIa}) compared to \text{UFH}
22Which clotting factors are affected by Warfarin due to its \text{Vitamin K} antagonism?
\text{Factors II}, \text{VII}, \text{IX}, and \text{X}
23What is the role of Antithrombin III in the mechanism of action for Heparin?
It is the cofactor that Heparin binds to and activates to inactivate clotting factors
24What is the main classification of anticoagulants that directly inhibit a single, activated clotting factor?
Direct Oral Anticoagulants (\text{DOACs}) or Novel Oral Anticoagulants (\text{NOACs})
25Which anticoagulant acts by blocking the recycling of \text{Vitamin K}?
Warfarin
26Which two key clotting factors are inhibited by Unfractionated Heparin?
Thrombin (\text{IIa}) and \text{Factor Xa}
27What specific molecular step does Direct Factor \text{Xa} Inhibitors prevent?
The conversion of Prothrombin (\text{Factor II}) to Thrombin (\text{Factor IIa})
28What is the mechanism by which \text{Protamine Sulfate} reverses Heparin?
It is a basic protein that chemically neutralizes the acidic Heparin molecule
29What is the classification for Warfarin?
\text{Vitamin K} Antagonist (Oral)
30What is the classification for Unfractionated Heparin (UFH)?
Indirect Thrombin Inhibitor / Heparin (Parenteral)
31What is the classification for Enoxaparin or Dalteparin?
Low Molecular Weight Heparin (\text{LMWH}) (Parenteral)
32What is the classification for Rivaroxaban or Apixaban?
Direct \text{Factor Xa} Inhibitor (Oral \text{DOAC})
33What is the classification for Dabigatran?
Direct Thrombin Inhibitor (DTI) (Oral \text{DOAC})
34Which classification of anticoagulants requires monitoring with \text{INR}?
\text{Vitamin K} Antagonists (e.g., Warfarin)
35What classification do Fondaparinux and Betrixaban belong to?
\text{Factor Xa} Inhibitors
36Which classification of anticoagulants primarily targets the potentiation of Antithrombin III?
Heparins (\text{UFH} and \text{LMWH})
37Which classification of oral anticoagulants specifically inhibits \text{Factor IIa}?
Direct Thrombin Inhibitors (e.g., Dabigatran)
38What is the general term for newer oral agents like Rivaroxaban and Dabigatran?
Direct Oral Anticoagulants (\text{DOACs}) or Novel Oral Anticoagulants (\text{NOACs})
39What is the antidote used to reverse the effects of Unfractionated Heparin (UFH)?
Protamine Sulfate
40What is the antidote used to reverse the effects of Warfarin?
Vitamin K (Phytomenadione)
41What is the specific agent used to reverse the effects of Dabigatran?
Idarucizumab (Praxbind)
42What is the specific agent used to reverse the effects of \text{Factor Xa} inhibitors like Rivaroxaban and Apixaban?
Andexanet Alfa (Andexxa)
43What is the primary mechanism by which Protamine Sulfate neutralizes Heparin?
It is a basic protein that chemically neutralizes the acidic Heparin molecule
44How does Vitamin K reverse the action of Warfarin?
It provides the necessary cofactor for the liver to synthesize functional clotting \text{Factors II, VII, IX, and X}
45What is the role of Idarucizumab?
It is a monoclonal antibody fragment that binds directly to Dabigatran, neutralizing its effect
46What is the classification of the drug whose effects can be reversed by Andexanet Alfa?
Direct \text{Factor Xa} Inhibitors
47What blood product may be used to provide immediate clotting factors for severe bleeding from Warfarin?
Four-factor Prothrombin Complex Concentrate (4F-PCC)
48Which anticoagulant's effects are only partially reversible by Protamine Sulfate?
Low Molecular Weight Heparin (\text{LMWH})