2214 – Pharmacology
Coagulation Modifier Drugs
Coagulation Modifier Drugs
HIGH ALERT DRUGS
Note that many factors affect their action on the body
1. Anticoagulants – inhibit action for formation of clotting factors, preventing clots from forming.
Like the name suggests: ANTI-CLOTTING
2. Antiplatelet drugs – prevent platelet plugs from forming by inhibiting platelet aggregation,
which can be beneficial for preventing heart attacks and strokes
3. Hemorheological drugs – alter platelet function without preventing platelets from working
4. Thrombolytic drugs – lyse existing clots
5. Antifibrinolytic drugs (hemostatic drugs) – have opposite effect, they actually promote blood
coagulation and help manage conditions where excessive bleeding would be harmful
**fibrinolysis breaks down clots!
Type of Coagulation Modifier Drug Class Individual Drugs
and Mechanism of Action
PREVENT CLOT FORMATION*
Anticoagulants*
Inhibit clotting factors IIa Heparins Unfractionated heparin
(thrombin) and Xa (heparin sodium) and low-
*REVERSAL DRUG: protamine molecular-weight heparins
sulphate (enoxaparin sodium,
dalteparin sodium,
nadroparin calcium)
Inhibit vitamin K–dependent Coumadins warfarin sodium (Coumadin®)
clotting factors II, VII, IX, and X
*REVERSAL DRUG: vitamin K
Inhibit clotting factors IIa and Glycosaminoglycans danaparoid sodium
Xa
Inhibit thrombin (factor IIa) Direct thrombin inhibitors Human antithrombin III,
argatroban, bivalirudin,
dabigatran etexilate mesylate
Inhibit factor Xa Selective factor Xa inhibitor fondaparinux, rivaroxaban,
apixaban
Antiplatelet Drugs*
, Interfere with platelet function P2Y12 inhibitors clopidogrel bisulphate,
prasugrel, ticagrelor
LYSE PREFORMED CLOTS**
Thrombolytics**
Dissolve thrombi Tissue plasminogen activators alteplase, tenecteplase
PROMOTE CLOT FORMATION***
Antifibrinolytics***
Prevent lysis of fibrin Systemic hemostats tranexamic acid, aprotinin
Reduce blood viscosity Hemorheological pentoxifylline
ANTICOAGULANTS
- Also called antithrombic drugs since they prevent the formation of emboli
- If emboli lodges in:
Coronary artery = myocardial infarction
Legs = deep vein thrombosis (DVT)
Brain vessel = stroke/cerebrovascular accident
Lungs = pulmonary embolus (PE)
General Anticoagulant MOA: no direct effect on blood clot that is already made, but they prevent the
formation of a new clot. They interfere with the clotting cascade at different points.
Mechanism of Action
Heparin
Inhibits circulating clotting factors
Binds to antithrombin III (AT-III) which turns of 3 activating factors: IIa (aka thrombin),
factor Xa, and factor IXa
Thrombin is the most sensitive to heparin because AT-III is the major inhibitor of
thrombin in the blood
Cannot lyse an existing clot, just prevents new ones from forming!!
Overall effect: turns off coagulation pathway
Has a short half-life, in case of toxicity, can be stopped. If severe, can use the antidote
protamine sulfate (e.g. during bypass surgery)
Two types of heparin:
Older version: unfractionated heparin (usually referred to a just heparin)
Larger molecule and derived from porcine intestine (ew.)
Binds primarily to:
IIa, Xa, and IXa
Requires frequent lab monitoring of bleeding times (important!!)
E.g. activated partial thromboplastin time (aPTT)
Newer version: low-molecular-weight heparin (LMWHs)
Coagulation Modifier Drugs
Coagulation Modifier Drugs
HIGH ALERT DRUGS
Note that many factors affect their action on the body
1. Anticoagulants – inhibit action for formation of clotting factors, preventing clots from forming.
Like the name suggests: ANTI-CLOTTING
2. Antiplatelet drugs – prevent platelet plugs from forming by inhibiting platelet aggregation,
which can be beneficial for preventing heart attacks and strokes
3. Hemorheological drugs – alter platelet function without preventing platelets from working
4. Thrombolytic drugs – lyse existing clots
5. Antifibrinolytic drugs (hemostatic drugs) – have opposite effect, they actually promote blood
coagulation and help manage conditions where excessive bleeding would be harmful
**fibrinolysis breaks down clots!
Type of Coagulation Modifier Drug Class Individual Drugs
and Mechanism of Action
PREVENT CLOT FORMATION*
Anticoagulants*
Inhibit clotting factors IIa Heparins Unfractionated heparin
(thrombin) and Xa (heparin sodium) and low-
*REVERSAL DRUG: protamine molecular-weight heparins
sulphate (enoxaparin sodium,
dalteparin sodium,
nadroparin calcium)
Inhibit vitamin K–dependent Coumadins warfarin sodium (Coumadin®)
clotting factors II, VII, IX, and X
*REVERSAL DRUG: vitamin K
Inhibit clotting factors IIa and Glycosaminoglycans danaparoid sodium
Xa
Inhibit thrombin (factor IIa) Direct thrombin inhibitors Human antithrombin III,
argatroban, bivalirudin,
dabigatran etexilate mesylate
Inhibit factor Xa Selective factor Xa inhibitor fondaparinux, rivaroxaban,
apixaban
Antiplatelet Drugs*
, Interfere with platelet function P2Y12 inhibitors clopidogrel bisulphate,
prasugrel, ticagrelor
LYSE PREFORMED CLOTS**
Thrombolytics**
Dissolve thrombi Tissue plasminogen activators alteplase, tenecteplase
PROMOTE CLOT FORMATION***
Antifibrinolytics***
Prevent lysis of fibrin Systemic hemostats tranexamic acid, aprotinin
Reduce blood viscosity Hemorheological pentoxifylline
ANTICOAGULANTS
- Also called antithrombic drugs since they prevent the formation of emboli
- If emboli lodges in:
Coronary artery = myocardial infarction
Legs = deep vein thrombosis (DVT)
Brain vessel = stroke/cerebrovascular accident
Lungs = pulmonary embolus (PE)
General Anticoagulant MOA: no direct effect on blood clot that is already made, but they prevent the
formation of a new clot. They interfere with the clotting cascade at different points.
Mechanism of Action
Heparin
Inhibits circulating clotting factors
Binds to antithrombin III (AT-III) which turns of 3 activating factors: IIa (aka thrombin),
factor Xa, and factor IXa
Thrombin is the most sensitive to heparin because AT-III is the major inhibitor of
thrombin in the blood
Cannot lyse an existing clot, just prevents new ones from forming!!
Overall effect: turns off coagulation pathway
Has a short half-life, in case of toxicity, can be stopped. If severe, can use the antidote
protamine sulfate (e.g. during bypass surgery)
Two types of heparin:
Older version: unfractionated heparin (usually referred to a just heparin)
Larger molecule and derived from porcine intestine (ew.)
Binds primarily to:
IIa, Xa, and IXa
Requires frequent lab monitoring of bleeding times (important!!)
E.g. activated partial thromboplastin time (aPTT)
Newer version: low-molecular-weight heparin (LMWHs)
