Drugs Affecting the Hematologic System

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Drugs Affecting the Hematologic System

• Pharmacology 49.222
• Bill Diehl-Jones RN, PhD
• Faculty of Nursing and Department of Zoology

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Agenda

• Zen Review
• blood components
• clotting cascades
• Drugs used to treat the following disorders
• Clotting
• Anemia
• Clinical gems

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Drugs Affecting the Hematologic System
Blood Components
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Overview of Clotting Process

• Platelets, Clots and Fibres

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Platelets are Key Components of the Clotting
Cascade

• Shrink damaged blood vessels
• Form hemostatic plugs
• Accelerate clotting

Plasma phospholipids
Receptors for Clotting factors
Factor XIII
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Clot Formation
Intrinsic Pathway
Extrinsic Pathway
Conversion of Clot Factors
XII
XIIa
Tissue Thromboplastin
XI
XIa
VII
VIIa
IX
IXa
Ca
VIII
VIIIa
X
Xa
V
Platelet Phospholipid
Prothrombin
THROMBIN
Fibrinogen
FIBRIN
XIII
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The Thrombolytic Pathway
PLASMINOGEN
XII
XIIa
PLASMIN
Fibrin Polymers
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Three Categories of Drugs

• Platelet Inhibitors
• Anticoagulants
• Thrombolytics

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Platelet Inhibitors

• Aspirin
• Blocks cyclooxygenase and formation of
  thromboxane A2
• Ticlopidine
• Inhibits binding of platelets to fibrinogen

Arachidonic Acid
Cyclooxygenase
Cyclooxygenase
Prostaglandins, Thromboxane
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Anticoagulants
Active Clotting Factors (IIa, IXa, X!a, XIIa,
XIIIa)

• Heparin
• Binds to antithrombin III
• Warfarin
• Vitamin K antagonist

Antithrombin III
Inactive Clotting Factors
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Thrombolytics

• tPA (Tissue Plasminogen Activator
• Activates plasminogen bound to fibrin
• Streptokinase
• Converts free plasminogen into active plasmin

Plasminogen
tPA, Streptokinase
Plasmin
Fibrin Degradation Products
Fibrin
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Anemias
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Clinical Gems