2. INTRODUCTION
• Drug that help prevent the clotting (coagulation) of blood.
• Coagulation will occur instantaneously once a blood vessel
has been severed.
• Blood begins to solidify to prevent excessive blood loss and
to prevent invasive substances from entering the blood
stream.
4. USEDIN VIVO
A. PARENTRAL ANTICOAGULANTS
I. Indirect thrombin inhibitors:
• Heparin, low molecular weight heparin(enoxaparin, daltiparin),
Fondaparinux, Danaparoid.
II. Direct thrombin inhibitors:
• Lepirudin, bivalirudin, argatroban.
5. USEDIN Vivo
B) ORAL ANTICOAGULANS.
1. Coumarin derivatives (vitamin k inhibitors):
• Bishydroxycoumarin, warferin sodium, acenocoumarol.
II Indandione derivatives:
• Phenindione
III Direct factor Xa inhibitors:
• Rivaroxaban.
IV Oral direct thrombin inhibitors:
• Dabigatran, etexilate
7. HEPARINE
• Heparin is a naturally-occurring anticoagulant produced by basophils
and mast cells to prevent formation and extension of blood clots.
• Chemically Heparin is a non-uniform mixture polymer of 2 sulfated
units having m.w 10,000 to 20,000.
• Heparin permits the body's natural clot lysis mechanisms, i.e.
fibrinolysis, to work normally break down previously formed clots.
• As the thrombokinase is released, it neutralizes the action of heparin to
allow clotting to occur
8. PHARMACOLOGICAL ACTION OF HEPARIN
• Antithrombin III is a peptide that is synthesized in the liver and
circulates in the plasma. Heparin activates plasma antithrombin III.
• Antithrombin III binds to and inhibits the activated thrombin and coagulation
factors (Xa and IXa).
• This is a physiological reaction, but heparin accelerates it by 1000 times.
Clotting time is prolonged.
• The heparinantithrombin III complex inhibits activated factor X and
thrombin, while low molecular weight (LMW) heparin only inhibits factor X
and not thrombin .
10. ADVERSE EFFECT OF HEPARIN
• Bleeding due to overdose
• Thrombocytopenia is another common problem
• Osteoporosis may develop on long term use of high dose.
• In rare Hypersensitivity reactions are occurs.
11. warfarin
• It is the most popular oral anticoagulant.
• The commercial preparation of warfarin is a mixture of R
(dextrorotatory) and S (levorotatory) enantiomers. The S form is more
potent and is metabolized relatively faster by ring oxidation carried out
by CYP2C9, while R form is less potent and degraded by side chain
reduction carried out by CYP1A and CYP3A4
• Both are partially conjugated with glucuronic acid and undergo some
enterohepatic circulation; finally excreted in urine.
12. WARFARIN
• Warfarin is rapidly and completely absorbed from intestines and is
99% plasma protein bound. It crosses placenta and is secreted in milk;
however, quantity of active form is generally insufficient to affect the
suckling infant.
13. ADVERSE REACTION
• Bleeding as a result of extension of the desired pharmacological action
is the most important problem causing ecchymosis, epistaxis,
hematuria, bleeding in the g.i.t. Intracranial or other internal
haemorrhages may even be fatal. Bleeding is more likely if therapy
is not properly monitored, or when INR exceeds 4, or interacting
drugs/contraindications are present.
