Anticoagulants: What are They?

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Posted on 3rd December 2010 by admin in Uncategorized

Anticoagulants are often prescribed to people who have medical conditions that require assistance in preventing blood from clotting.  Conditions that cause excessive clotting like leg or lung clots, irregular heart rhythm, artificial heart valves and blood clots in the heart often require the use of anticoagulants.  This blog and others may interest you if you are attempting to get your strength and conditioning certification.

There are two ways that an anticoagulant can prevent blood from clotting.  An anticoagulant can bind or precipitate calcium so that it is unavailable to the coagulation process.  It can also inhibit the formation of thrombin, which is needed to convert fibrinogen into fibrin during the coagulation process.

The most common anticoagulants are ethylenediaminetetraacetic acid (EDTA), citrates, heparin and oxalates.

EDTA prevents coagulation by binding to calcium.  It is used to preserve cell morphology and inhibits platelet clumping.  EDTA is often used to provide whole blood specimens for hemotology tests and is also increasingly being used in blood banks.  Blood specimens should be mixed with EDTA immediately after collection to prevent platelet clumping.

Citrates also prevent coagulation from occurring by binding to calcium.  Sodium citrate is most often used because it is effective at preserving the coagulation factors.

Heparin prevents thrombin formation in the blood.  The enzyme thrombin is necessary to convert fibrinogen into fibrin for clot formation.  When heparin is mixed immediately upon collection it prevents clot formation and fibrin from being created.

Oxalates precipitate calcium in the blood preventing coagulation.  Potassium oxalate is the most widely used.  Oxalate tubes should be filled to the stated capacity.  Excess oxalate can destroy the red blood cells and release hemoglobin into the plasma.

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