Week 3 -Anticoagulant, Antiplatelet and Thrombolytic Flashcards
What are anticoagulant drugs?
- Anticoagulant drugs are primarily prophylactic, preventing fibrin deposits and thrombus extension.
- They do not dissolve existing clots.
What are the main types of Anticoagulant drugs
- Heparin & Low-Molecular-Weight Heparins (LMWHs) (e.g., enoxaparin) – Inactivate factor Xa, act immediately IV, LMWHs are given subcutaneously, safer, and need less monitoring.
- Warfarin – A vitamin K antagonist, inhibits clotting factor activation.
- Direct Factor Xa Inhibitors – Includes apixaban and rivaroxaban.
What are antiplatelet drugs, and how do they work?
Antiplatelet drugs treat arterial thrombosis by suppressing platelet activation enzymes. Common drugs include:
- Aspirin
- Clopidogrel
What are thrombolytic drugs, and how do they work?
Thrombolytic (fibrinolytic) drugs convert plasminogen to plasmin, which dissolves fibrin clots. Example:
- Alteplase (rt-PA) – A recombinant tissue plasminogen activator.
What is the Prothrombin Time (PT) test?
The PT test measures the extrinsic coagulation pathway and is used to determine the INR (International Normalized Ratio).
How is the PT test used in clinical practice?
It helps monitor warfarin therapy and detect coagulation factor deficiencies.
- Normal INR: 1.0–1.3
- Therapeutic INR for warfarin patients (e.g., DVT): 2.0–4.0
Prolonged PT/INR can indicate:
- Coagulation factor deficiency in the extrinsic pathway.
- Warfarin presence.
What is the Activated Partial Thromboplastin Time (aPTT) test?
The aPTT test measures the intrinsic coagulation pathway and evaluates clotting factor function.
How is the aPTT test used in clinical practice?
It is mainly used to monitor heparin therapy.
- Normal range: 26–39 seconds
- Therapeutic range for heparin patients: 50–90 seconds
Prolonged aPTT can indicate:
- Intrinsic pathway coagulation factor deficiency.
- Heparin presence.
- aPTT does NOT monitor LMWH effects.
