Cardiovascular Medications Quiz

Study Notes

"Hemostasis" combines "hem-", meaning blood, and "-stasis", meaning to stop; it refers to the stopping of blood flow.
A vital mechanism that protects the body from excessive blood loss following external or internal injuries.
The process culminates in the formation of a blood clot, preventing severe hemorrhage.
Multiple clotting factors are activated through a sequential cascade of events during hemostasis.

Coagulation, or clotting, transforms blood from liquid to gel, creating a blood clot.
The Coagulation Cascade is a series of steps triggered by tissue injury, wherein each step activates the subsequent one, ultimately forming a clot.
The Intrinsic Pathway is activated in response to internal blood vessel injury.
The Extrinsic Pathway occurs when blood leaks from vessels into tissue spaces.
Fibrinogen (clotting factor I) converts to fibrin, which binds platelets and plasma proteins to form a hemostatic plug.
Prothrombin (clotting factor II) activates thrombin, which plays a crucial role in the clotting process.

Anticoagulants are medications that prolong bleeding time to prevent thrombi formation or expansion.
They impart a negative charge to platelets, inhibiting their aggregation.
The process of clot breakdown is known as fibrinolysis.

Enhances the action of antithrombin III, a plasma protein that inactivates thrombin and other procoagulant enzymes, thereby inhibiting coagulation.
Administered via IV for rapid action; prevents the formation of fibrin clots within minutes.
Heparin is often referred to as unfractionated heparin, differentiating it from low-molecular-weight heparins (LMWHs).
LMWHs are modified heparin with a more specific action towards active Factor X, longer half-life, and a more stable response than unfractionated heparin.

A type of low-molecular-weight heparin that operates similarly to heparin, but is more selective in its inhibition.
Demonstrates a duration of action that is two to four times longer than heparin.
Preferred for various clotting disorders and post-surgical DVT prevention due to a lower risk of thrombocytopenia.

Monitor activated Partial Thromboplastin Time (aPPT) and platelet counts.
Administer subcutaneously in the abdomen at a 90º angle using a 25-28 G needle; do not aspirate or massage after injection.
IM administration is contraindicated to reduce bleeding risk.
The normal aPPT range is 20 to 40 seconds; therapeutic levels should be maintained at 1.5 to 2.5 times the normal value during continuous infusion.
aPPT should be measured every 4 to 6 hours initially, and then daily thereafter.
The antidote for heparin overdose is Protamine Sulfate.

Warfarin inhibits the hepatic synthesis of coagulation factors II, VII, IX, and X.
Its anticoagulant effect may take several days to achieve maximum efficacy.
Warfarin prolongs clotting times, specifically Prothrombin Time (PT) and International Normalized Ratio (INR).