Anticoagulants fight against blood coagulation or clots. Anticoagulants are divided into two groups of coumarin derivaties and heparins. They both have the same purpose of decrease the extension of blood clots in conditions such as venous thrombosis, pulmonary embolism, and coronary occlusion. They do not dissolve clots; they only interfere with the coagulation process as a prophylaxis.
– coumarin derivatives such as Coumadin are administered orally. They alter the synthesis of blood coagulation factors in the liver by interfering with the actions of vitamin K. The antidote for bleeding complications with Coumadin therapy is of course vitamin K. the action of coumarin derivatives are much slower than heparin. The laboratory method of monitoring the therapy with coumarin derivatives is the International Normalized Ration (I N R).
– heparin has its own two kinds as well – standard or unffractionated type (U F H) and the new type, low molecular weight (L M W). Heparin is not absorbed in GI tract and must be administered intravenously or subcutaneously. Low Molecular Weight type heparin is only administered via subcutaneous injection. The heparin acts on thrombin, inhibiting action of fibrin in clot formation.
The antidote for serious bleeding complications during heparin therapy is protamine effect. L M W Hs such as Lovenox or enoxaparin through subcutaneous have higher bioavailability and produce more predictable anticoagulant response than standard U F H.
L M W H enoxaparin is approved for prevention of D V T, unstable angina, non-Q wave M I, and pulmonary embolism. Lab test of PTT is important for heparin.
Platelet Inhibitors are given as prophylactic therapy to decrease platelet clumping.
– Dipyridamole is a non-nitrate coronary vasodilator that inhibits platelet clumping.
– Aspirin of post M I or recurrent transient ischemic attacks (T I As)
-Clopidogrel Plavix is an oral antiplatelet agent used to reduce atherosclerotic events ( M I, stroke and vascular death).
Thrombolytic agents potentiate the process of body to dissolve clots also known as fibrinolysis. When given I V thrombolytic agents within first few hours, they reduce mortality fates of M I and C V A. They are administered in an E R or I C U settings.
Colony Stimulating Factors (C S F S) such as epoetin are responsible for regulation of the production and development of blood cells normally in the bone marrow. Epoetin alfa is approved for treatment of anemia and stimulates bone marrow to produce red blood cells. Side effects are flu like symptoms and chest pain.