[05.20] Thrombolytics and Anticoagulants V2.1.pdf

Endothelium

What wraps the inside of blood vessels

Trauma or plaque rupture

What two events can damage the endothelium

Collagen

What is exposed underneath when breaks occur in the endothelium

Von Willebrand Factor (vWF)

What factor facilitates the attachment of platelets to the vessel wall

Glycoprotein Ia and Ib

What receptors on platelet surfaces do vWF and collagen attach to

Adenosine diphosphate (ADP), Thromboxane A2 (TXA2), Serotonin/5-hydroxytryptamine (5-HT)

What three chemicals do platelets release when they are activated

Recruit and activate more platelets

What is the function of the chemicals released by activated platelets

Fibrinogen and GPIIb/IIIa

What two components link platelets to each other

Fibrinogen

What links two platelets together

GPIIb/IIIa

What serves as the point of attachment and linkage for fibrinogen

Platelet plug

What is formed by the continuous recruitment and binding of platelets

Factor X and V

What two factors are activated in the final common pathway of coagulation

Prothrombin to thrombin

What conversion is catalyzed by activated Factor X and V

Positive feedback

What process does activated thrombin undergo

Fibrinogen into fibrin

What conversion is catalyzed by activated thrombin

Arteries

What blood vessels deliver blood from the heart to the circulation

Thicker tunica media

What structural layer is thicker in arteries

High pressure and high velocity

What characterizes the blood flow in arteries

Platelets

What are the primary cause of clot or thrombosis in arteries

White clot

What type of clot is mostly made up of platelets that form the thrombus

Faster to form platelet clots

Why do white clots form in arteries

Veins

What blood vessels bring back blood to the heart

Thinner tunica media

What structural layer is thinner in veins

Low pressure and low velocity

What characterizes the blood flow in veins

Fibrin clot formation (secondary hemostasis)

What is allowed by the low velocity of blood flow in veins

Red clot

What type of clot forms fibrin that traps red blood cells

Agents to address platelets

What type of agents should be given if thrombosis is suspected in an artery

Agents directed at secondary hemostasis

What type of agents should be given if thrombosis is suspected in a vein

Atherosclerosis

What condition involves damage to vessel walls and plaque rupture, often treated with antiplatelets and anticoagulants

Myocardial infarction (MI)

What can plaque rupture lead to

Cerebrovascular diseases (e g stroke, transient ischemic attacks)

What can plaque rupture lead to in the brain

Peripheral arterial occlusive disease (PAOD)

What condition involves clots in the limbs

Acute limb ischemia

What condition presents with cold, dark, and painful extremities due to vessels occluded by clots

Deep vein thrombosis (DVT) and Pulmonary embolism (PE)

What are the two forms of Venous thromboembolism

Atrial fibrillation

What condition involves an abnormality in the contraction of the atrium (irregularly irregular rhythm)

Stasis in chambers

What does atrial fibrillation cause that can lead to thrombus formation

Thrombophilia

What group of inherited disorders involves blood being hypercoagulable

Inhibit aggregation of platelets

What is the general mechanism of action of antiplatelet drugs

Coronary artery disease, myocardial infarction

What two conditions are antiplatelets used to manage, especially if arteries are involved

Prophylaxis against stroke

What is a use of antiplatelets in cerebrovascular disease

Cilostazol

What antiplatelet is especially indicated for peripheral arterial occlusive disease

Inhibit conversion of arachidonic acid to TXA2

What is the mechanism of action of Aspirin and NSAIDs

Cyclooxygenase enzymes (COX-1 and COX-2)

What enzymes transform arachidonic acid into TXA2

Inhibits COX-1 and COX-2 (nonspecific)

What is the specific action of Aspirin on COX enzymes

Inhibits COX-2 (anti-inflammatory)

What is the specific action of other NSAIDs on COX enzymes

Inhibit ADP from binding to receptors

What is the mechanism of action of Thienopyridines

5’AMP

What substance, when converted from cAMP, causes the release of calcium and calls on other platelets

Inhibit the crosslinking by fibrinogen between different platelets

What is the mechanism of action of GPIIb/IIIa Inhibitors

Arteries

What circulatory system is primarily involved when antiplatelets are indicated

Irreversible inhibitor of COX-1 and COX-2

What is the mechanism of action of Aspirin

Oral

What is the route of administration for Aspirin

80 mg per day

What is the typical dose of Aspirin

Prostaglandin synthesis is inhibited

What is the cause of gastrointestinal upset as a side effect of Aspirin

Give more platelets

What is the management for a bleeding patient taking aspirin

One week

How long is Aspirin typically held off before surgery

Platelet function returns to normal

What happens after one week because inhibited platelets die

Clopidogrel, Prasugrel, Ticagrelor, Ticlopidine

What are the four examples of Thienopyridines

Oral

What is the route of administration for Thienopyridines

MI patients

What patient group is Clopidogrel indicated for

Patients undergoing coronary artery stenting

What patient group is Prasugrel important for

Thrombotic thrombocytopenic purpura (TTP)

What severe side effect may Ticlopidine cause

Inhibits phosphodiesterase (PDE)

What is the mechanism of action of PDE and Adenosine Uptake Inhibitors

Increases cAMP, Reduces Ca+, Inhibition of platelet activation

What are the three subsequent effects of inhibiting PDE

Dipyridamole and Cilostazol

What are the two examples of PDE and Adenosine Uptake Inhibitors

Oral BID

What is the route of administration and frequency for PDE and Adenosine Uptake Inhibitors

Patients with strokes

What condition are PDE and Adenosine Uptake Inhibitors given for

Claudication

What condition is Cilostazol specifically given for

Vasodilation

What is a side effect of PDE and Adenosine Uptake Inhibitors that can lead to hypotension

Abciximab, Eptifibatide, Tirofiban

What are the three examples of Glycoprotein IIB/IIIA Inhibitors

Intravenous (IV) bolus then infusion

What is the route of administration for Glycoprotein IIB/IIIa Inhibitors

Thrombocytopenia through immune-mediated mechanisms

What is a side effect of Glycoprotein IIB/IIIa Inhibitors

Crushed, dissolved, then placed in a nasogastric tube (NGT)

How are oral antiplatelet drugs administered to patients who are unable to swallow

Secondary hemostasis

What phase of clotting involves more time to form a clot

Venous system

Where are problems with clotting usually seen

Vitamin K antagonists

What class of anticoagulants inhibit the synthesis of protein C and clotting factors X, IX, VII, and II

Warfarin

What is an example of a Vitamin K antagonist

Inhibit thrombin and factor X

What is the action of Antithrombin III

Factors X, IX, VII, and II

What are the Vitamin K-Dependent Clotting Factors (mnemonic 1972)

Acute myocardial infarction

What condition, when treated with anticoagulants, usually uses IV anticoagulants such as heparin and enoxaparin

Post-valve replacement

What intervention requires anticoagulants to prevent clots from forming on the new heart valve

Prolonged sitting, long-haul flights, ICU/bed-ridden patients, orthopedic surgeries

What four groups of patients are at risk for DVT/PE

Inhibit carboxylation of Vitamin K dependent clotting factors

What is the mechanism of action of Warfarin

Depletes protein C

What action of Warfarin causes an initial prothrombotic effect

WARF: Wisconsin Alumni Research Foundation

What does WARF stand for in the name "Warfarin"

Kill rats

What was Warfarin originally used for in the Philippines

Oral

What is the route of administration for Warfarin

CYP450 system

What metabolizes Warfarin

Narrow therapeutic window

What characteristic of Warfarin requires cautious dose adjustment

Prothrombin time (PT), international normalized ratio (INR)

What is Warfarin monitored by

36 hours

What is the plasma half-life of Warfarin

Vitamin K, Fresh Frozen Plasma (FFP), rFVII (Factor VII), FEIBA/aPCC

What four agents are used to reverse the side effects of Warfarin

Vitamin K

What is administered everyday until bleeding stops to reverse Warfarin's side effects

Limit intake of green leafy vegetables

What dietary advice is given to patients taking Warfarin, due to high Vitamin K content

Activates antithrombin III

What is the mechanism of action of Heparin

Factor X and thrombin

What two factors does Antithrombin III mostly and partly inhibit, respectively

Mucopolysaccharide

What is Heparin chemically classified as

IV or subcutaneous

What are the routes of administration for Heparin

Partial Thromboplastin Time (PTT)

What is Heparin monitored by

3-6 hours

What is the short half-life of Heparin

Bolus and continuous drip

How is Heparin given due to its short half-life