Anticoagulants

Question 1

Limitations of Heparin

Answer 1

• Narrow Therapeutic Index
• Variable Dose Response
• Decreased ability to neutralize thrombin bound to fibrin
• Thrombocytopenia

Question 2

Heparin Monitoring Points

Answer 2

Monitor aPTT (1.5-2.5x control), platelets
Signs of bleeding Hematocit and hemoglobin levels Vital signs
Assess for sources of bleeding
Hematuria, hematochezia, epistaxis, purpura,
hematemesis, stools

Question 3

Low Molecular Weight Heparins (LMWH)

Answer 3

• Dalteparin
• Enoxaparin
• Tinzaparin
• Fondaparinux

Question 4

Precautions with LMWHs

Answer 4

Epidural or spinal anesthesia
Previous history of HIT, aneurysms, cerebral
hemorrhage, uncontrolled HTN, threatened abortion
Geriatric patients with history of
Bacterial endocarditis, bleeding disorders, ulcer
disease, angiodysplasia, hemorrhagic stroke
Blood dyscrasias, recent childbirth, renal
insufficiency, severe CNS trauma

Question 5

Warfarin (Coumadin) MOA

Answer 5

Blocks the ability of vitamin K to carboxylate
the vitamin K dependent clotting factors
which reduces their coagulant activity

Question 6

Prevent clot formation and extension?

Answer 6

Anticoagulants

Question 7

Interfere with platelet activity?

Answer 7

Antiplatelet Drugs

Question 8

Dissolve existing thrombi?

Answer 8

Thrombolytic Agents

Question 9

Warfarin Indications?

Answer 9

-Venous thrombosis and its extension
-Pulmonary embolism
-Thromboembolic complications associated with
AF and cardiac valve replacement
-Post MI
-Cardiac Embolism

Question 10

Warfarin Major Risk?

Answer 10

Hemorrhage!

Question 11

What Clinical Test measures Warfarin?

Answer 11

INR

Question 12

Protocol for transitioning Heparin to Warfarin?

Answer 12

Heparin should be continued for a minimum
of four days
›Time to peak antithrombotic effect of warfarin is
delayed 96 hours (despite INR)
When INR reaches desired therapeutic
range, discontinue heparin (after a minimum of four days)

Question 13

Warfarin Dose and Monitor Protocol?

Answer 13

Start low
›Initiate 5 mg daily ›Educate patient
Stabilize
›Titrate to appropriate INR ›Monitor INR frequently (daily then weekly)
Adjust as necessary Monitor INR regularly (every 1–4 weeks) and
adjust

Question 14

Warfarin Warning Levels for INR?

Answer 14

Low-intensity treatment:
›Efficacy rapidly diminishes below INR 2.0* ›No efficacy below INR 1.5
High-intensity treatment:
›Safety compromised above INR 4
INR below 2 increases chance of stroke
dramatically

Question 15

Antithrombotic/Antiplatelet Uses and Indications?

Answer 15

Stroke risk reduction 
Status post stroke 
Treatment for Atrial Fibrillation 
Prosthetic Valve replacements 
DVT treatment and prophylaxis 
Pulmonary embolus treatment 
Status post myocardial infarction with and without
stent
Treatment and prevention of Heparin-Induced
Thrombocytopenia (HIT

Question 16

Antiplatelet specific indications?

Answer 16

Used in management of acute ischemic stroke and
stroke prevention
MI, stroke, arteriosclerosis
Initial therapy