Hematological Agents - Pharmacology

Question 1

Anti-Coagulation Drug Classes - Names (5) + Protype Drug + Mechanisms

Answer 1

1) Heparin - Unfractioned + Enoxaprin - Activates Anti-Thrombin III (Inhibits Factors IIa and Xa
2) Direct Thrombin Inhibitors (DTIs) - Lepirudin + Dabigatran (Oral) - Inhibit Thrombin (IIa)
3) Warfarin - Coumadin - Blocks Vitamin K Restoration (Factors II, VII, IX, X, C, and S)
4) Factor X Inhibitors - Rivaroxiban
5) Fibrinolysis (Thrombolytic) - tPA (Alteplase) - Activates Plasminogin to Plasmin to break down fibrin

Question 2

Protamine - Class

Answer 2

Reverse Heparin

Question 3

Direct Thrombin Inhibitors - Names (3) + Mechanism + Use + Toxicities

Answer 3

Names - Lepirudin (IV) + Dabigratan (New + Oral) + Argatroban
Mechanisms - Blocks Thrombin (IIa) - From Hirudin in leeches)
Uses - PE + DVT + MI - Key or patients with Thrombocytopenia
Toxicities - Bleeding (Monitor aPTT) + Anaphylaxis (Lepirudin)

Question 4

Factor X Anticoagulants - Names (1) + Mechanism + Use + Toxicities (2)

Answer 4

Names - Rivaroxaban
Mechanisms - Inhibits Factor Xa directly (oral)
Uses - DVT/Afib etc.
Toxicities - Bleeding - No reversal agents + less monitoring PTT checking

Question 5

Lepirudin - Class

Answer 5

DTI

Question 6

Unfractioned Heparin - Key Fact

Answer 6

Highest risk of thrombocytopenia + monitoring but most reversible

Question 7

Heparin Induced Thrombocytopenia (HIT) - Pathology + Risk

Answer 7

Antibodies form to heparin-IVa complex –> Increases the risk for clotting + lowers platelets + activates tissue factor

Question 8

Abciximab - - Mechanism + Use + Toxicity (2)

Answer 8

Mechanism - GP IIb/IIIa receptor blocker - forms the fibirin link between platelets in aggregation after vWF and the GPIb receptor link up
Use - PCI + ACS
Toxicity - Bleeding + Thrombocytopenia with prolonged use

Question 9

Enoxaprain - Class

Answer 9

Lovenox - LWMH

Question 10

Anti-Platelet Agents - Names (4) + Mechanisms

Answer 10

Aspirin (ASA) - COX1 Inhibitor - Inhibits Thomboxane A2 Production (more than PGE2 beacuese platelets cannot make new TXA2)
Clopidogrel (Plavix) + Prasugrel (Eficent) - ADP Receptor Antagonists - Prevents platelet aggregation
Abciximab + Eptifibatide - GP IIb/IIIa receptor blocker - forms the fibirin link between platelets in aggregation after vWF and the GPIb receptor link up
Dipyridamole - Inhibits adenosine uptake and saves cAMP

Question 11

Heparin - Names (3) + Mechanisms + Uses + Toxicities (3)

Answer 11

Names - Unfractioned (High Weight) + Enoxaparin (Lovenox/Low Weight) + Fondaparinux (Arixtra)
Mechanisms - Mimics intrinsic heparin to activate Anti-Thrombin III (Inhibits IIa and Xa)
Uses - Anti-coagulation - Lower Weight = More Factor X Specific = Less Reversible
Toxicities - Bleeding + Thrombocytopenia (not with Fondaparinux) + Osteoporosis (Chronic Use) - Moniter Activated PTT (aPTT)
Reversed with - Protamine (Can’t Reverse Fondaparinux)

Question 13

Clopidogrel - Mechanism + Use + Toxicity (3)

Answer 13

Mechanism - ADP Receptor Antagonist
Use - Prevents Platelet Aggregation - Big for PCI
Toxicity - Bleeding + GI + Hematologic Abnormalities

Question 14

Argatroban - Class

Answer 14

DTI

Question 15

Vitamin K Blocker - Names (1) + Mechanism + Use + Toxicities (5)

Answer 15

Names - Warfarin (Coumadin)
Mechanisms - Inhibits Vitamin K Recycling - Inhibits Factors II, VII, IX, X, C, S -
Uses - Long-term anticoagulation for Afib DVT etc.
Toxicities - First increases risk of clot (protein C knocked out while II is still in half life) + teratogen + skill necrosis + bleeding + CYP450 and small therapeutic window

Question 16

Warfarin - Class

Answer 16

Vitamin K Inhibitor

Question 17

ASA - Mechanism + Use + Toxicity (2)

Answer 17

Mechanism - COX1 Inhibitor - Inhibits Thomboxane A2 Production (more than PGE2 beacuese platelets cannot make new TXA2)
Use - Anti-platelet - Low Dose
Toxicity - GI = Peptic Ulcer/Bleed + Bleeding

Question 18

Prasugrel - Mechanism + Use + Toxicity (3)

Answer 18

Mechanism - ADP Receptor Antagonist
Use - Prevents Platelet Aggregation - Big for PCI
Toxicity - Bleeding + GI + Hematologic Abnormalities

Question 19

Alteplase - Class

Answer 19

tPA

Question 21

Fibrinolysis Drugs - Names (2) + Mechanism + Use + Toxicities (1)

Answer 21

Names - tPA (Alteplase)
Mechanisms - Activates Plasminogen to become Plasmin which breaks down fibrin/the clot
Uses - Clot-Buster
Toxicities - Bleeding, especially cerebral

Question 21

Fondaparinux - Class

Answer 21

Artixtra - Very LWMH - Not Reversible

Question 21

Dabigatran - Class

Answer 21

DTI

Question 21

Rivaroxaban - Class

Answer 21

Direct Xa Inhibitor