Anticoagulants, commonly referred to as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time.
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Coagualnts and Anticoagulant
1. Seminar
on
Drug Affecting Blood and Blood Formation: Coagulant and
Anticoagulant
๏ A seminar for the partial fulfillment of the requirement for
the Degree of Bachelor of Pharmacy In Sant Gadge Baba
Amravati University.
๏ Submitted By-
๏ Shruti Rajeev Gautam
๏ (B.Pharmacy 4th year 7thSemester)
๏ Guide-
๏ Prof. Dr. S.D.Pande
๏ Vidya Bharati College of Pharmacy, Amravati.
๏ 2018-2019
3. Coagulation
๏ Coagulation (also known as clotting) is the process by
which blood changes from a liquid to a gel, forming a
blood clot.
๏ It potentially results in hemostasis, the cessation of
blood loss from a damaged vessel, followed by repair.
4. Mechanism
๏ There is an injury to the blood vessel wall a primary
mechanism operates to form platelets plugs followed by
the secondary mechanism of haemostasis or blood
coagulation which operate to form the fibrin clot
5. Primary mechanism
Vessel wall injury
(endothelial cell)
Expose to collagen
Adherence of platelet to collagen
(platelet surface interaction )
Release of ADP
PLATELET aggregation
(platelet-platelet interaction )
Platelet mass
(Platelet plug )
6. Coagulation factors
FACTOR
FACTOR I Fibrinogen
FACTOR II Prothrombin
FACTOR III Tissue thromboplastin
FACTOR IV Calcium
FACTOR V Proaccelerin
FACTOR VI (not an independent factor)
FACTOR VII Proconvertin
FACTOR VIII Anithaemophilic globulin (AHG-A)
FACTOR IX Christmas factor (AHG -B)
FACTOR X Stuart-prower factor
FACTOR XI Plasma thromboplastin antecedent
(AHG-C)
FACTOR XII Hageman factor
FACTOR XIII Fibrin stabilizing factor
10. Vitamin K :-
๏ It is fat soluble principle required for the synthesis of
clotting factors
๏ Action: vit k act as a cofactor at a late stage in the
synthesis by liver of coagulation protein โprothrombin ,
factor VII, IX and X
๏ utilization : fat soluble form of vit k are absorbed from
the intestine via lymph and require bile salt for
absorption while water soluble form are absorbed
directly into portal blood
11. ๏ Deficieny : deficieny of vit k occur due to liver disease
,obstructive jaundice , malabsorption ,long term
antimicrobial thearpy which alters intestial flora
๏ Uses: dietary deficieny, prolonged antimicrobial
therapy,obstructive jaundice , liver disease
๏ Advers effect: allergic reaction
12.
13. DRUG INTERACTIONS
๏ Temporary resistance to prothrombin-depressing
anticoagulants may result, especially when larger doses
of phytonadione are used. If relatively large doses have
been employed, it may be necessary when reinstituting
anticoagulant therapy to use somewhat larger doses of
the prothrombin- depressing anticoagulant, or to use
one which acts on a different principle, such as heparin
sodium.
14. Anticoagulant
๏ Anticoagulants, commonly referred to as blood
thinners, are chemical substances that prevent or
reduce coagulation of blood, prolonging the clotting
time.
๏ Drug used to reduce the coagulability of blood
15.
16. Drug
๏ Used in vivo
๏ A) Parental Anticoagulants
(1) Indirect Thrombin Inhibitor: Heparin ,low molecular
weight heparin , fondaparinux , danapariod
(2) Direct Thrombin Inhibitor : Lepirudin , Bivalirudin,
Argatroban
17. ๏ B.) Oral anticoagulant
(1) Coumarin Derivatives: Bishydroxycoumarin, Warfarin
sod , Acenocoumarol, Ethylbiscoumacetate
(2) Indandione derivative : Phenindione
(3) Direct factor Xa inhibitors : Rivaroxaban
(4) Oral direct thrombin inhibitor : Dabigatran etexilate
18. ๏ Used in vitro
๏ A) Heparin
๏ B) Calcium Complexing Agent :
Sodium citrate
Sodium Oxalate
Sodium edetate
20. HEPARIN
๏ Heparin is a non uniform mixture of straight chain
mucopolysaccharides with MW10,000 to 20,000
๏ Heparin carries strong electronegative charges and is
the strongest organic acid present in the body
๏ Is present in all tissue containing mast cell richest
source are lung ,liver and intestinal mucosa
๏ Action :
๏ Anticaogulant: Heparin is a powerful and instanteously
acting anticoagulant effective both in vivo and in virto.
it acts indirectly by activating plasma antithrombin III
๏ Antiplatelet: Heparin in higher doses inhibits platelet
aggregation and prolong bleeding time
๏ Lipaemia clearing : injection of hepain clears turbid post
prandil lipaemia plasma by releasing a lipoprotein
lipase from vessel wall and tissue
22. Mechanism of action
๏ Heparin binds to the enzyme inhibitor antithrombin III
(AT), causing a conformational change that results in its
activation through an increase in the flexibility of its
reactive site loop. The activated AT then inactivates
thrombin, factor Xa and other proteases. The rate of
inactivation of these proteases by AT can increase by up
to 1000-fold due to the binding of heparin.Heparin
binds to antithrombin via a specific pentasaccharide
sulfation sequence contained within the heparin
polymer
24. Adverse effect
๏ A serious side-effect of heparin is heparin-induced
thrombocytopenia(HIT), caused by an immunological
reaction that makes platelets a target of immunological
response, resulting in the degradation of platelets,
which causes thrombocytopenia. This condition is
usually reversed on discontinuation, and in general can
be avoided with the use of synthetic heparins. Also, a
benign form of thrombocytopenia is associated with
early heparin use, which resolves without stopping
heparin
25. DRUG INTERACTION
๏ Oral anticoagulants
๏ Heparin sodium may prolong the one-stage
prothrombin time Therefore, when heparin sodium is
given with dicumarol or warfarin sodium, a period of at
least 5 hours after the last intravenous dose should
elapse before blood is drawn if a valid prothrombin time
is to be obtained.
๏ Platelet inhibitors
๏ Drugs such as acetylsalicylic acid, dextran,
phenylbutazone, ibuprofen, indomethacin,
dipyridamole, hydroxychloroquine and others that
interfere with platelet aggregation reactions (the main
hemostatic defense of heparinized patients) may induce
bleeding and should be used with caution in patients
receiving heparin sodium.
26. Drug/Laboratory Test
Interactions
๏ Significant elevations of aminotransferase (SGOT [S-AST]
and SGPT [SALT]) levels have occurred in a high
percentage of patients (and healthy subjects) who have
received heparin. Since aminotransferase
determinations are important in the differential
diagnosis of myocardial infarction, liver disease, and
pulmonary emboli, rises that might be caused by drugs
(like heparin) should be interpreted with caution
27. Antidote to heparin
๏ Protamine sulfate has been given to counteract the
anticoagulant effect of heparin (1 mg per 100 units of
heparin that had been given over the past four hours).
It may be used in those who overdose on heparin or to
reverse heparin's effect when it is no longer needed
28. WARNING:-
๏ Heparin is not intended for intramuscular use.
๏ Cardiovascular โsubacute bacterial endocarditis.
Severe hypertension.
๏ Surgical โ During and immediately following (a) spinal
tap or spinal anesthesia or (b) major surgery, especially
involving the brain, spinal cord or eye.
๏ Hematologic โ Conditions associated with increased
bleeding tendencies, such as hemophilia,
thrombocytopenia and some vascular purpuras.
๏ Gastrointestinal โ Ulcerative lesions and continuous
tube drainage of the stomach or small intestine.
๏ Other โ Menstruation, liver diseasewith impaired
hemostasis.
30. Warafarin sodium
๏ It is most popular oral anticoagulant
๏ The commercial perparation of warafarin mixture of R
and S enantiomer .S form is more potent than R
๏ Crystalline warfarin sodium occurs as a white, odorless,
crystalline powder that is discolored by light. It is very
soluble in water, freely soluble in alcohol, and very
slightly soluble in chloroform and ether.
๏ It is commonly used to treat blood clots such as deep
vein thrombosis and pulmonary embolism and to
prevent stroke in people who have atrial fibrillation,
valvular heart disease or artificial heart valves. Less
commonly it is used following ST-segment elevation
myocardial infarction (STEMI) and orthopedic surgery. It
is generally taken by mouth but may also be used by
injection into a vein
31. ๏ Warfarin first came into commercial use in 1948 as a rat
poison .
๏ In 1954 it was approved for medical use in the United
States.[4] It is on the World Health Organization's List of
Essential Medicines, the most effective and safe
medicines needed in a health system
๏ Warfarin is used to decrease the tendency for
thrombosis or as secondary prophylaxis (prevention of
further episodes) in those individuals who have already
formed a blood clot . Warfarin treatment can help
prevent formation of future blood clots and help reduce
the risk of embolism
๏ Warfarin, sold under the brand name Coumadin
32.
33. Pharmacokinetic data
a) Bioavailability :79-100% (by mouth)
b) Metabolism :liver
c) Elimination half life : 1 week (active half-life is 20-60
hours)
d) Excretion: kidney
e) Protein binding :99%
34. Mechanism of action
๏ warfarin is one of several drugs popularly referred to as
a "blood thinner"; this is a misnomer since it does not
affect the viscosity of blood.
๏ Warfarin inhibits the vitamin K-dependent synthesis of
biologically active forms of the calcium-dependent
clotting factors II, VI, IX and X, as well as the regulatory
factors protein C, protein S, and protein Z
35. Adverse effect
๏ Bleeding
๏ The only common side effect of warfarin is bleeding.
The risk of severe bleeding is small but definite (a
typically yearly rate of 1-3% has been reported)[and any
benefit needs to outweigh this risk when warfarin is
considered. All types of bleeding occur more commonly,
but the most severe ones are those involving the brain
(intracerebral hemorrhage/hemorrhagic stroke) and the
spinal cord.Risk of bleeding is increased if the INR is out
of range (due to accidental or deliberate overdose or
due to interactions). This risk increases greatly once the
INR exceeds 4.5
36. Warfarin necrosis
๏ A rare but serious complication resulting from
treatment with warfarin is, warfarin necrosis which
occurs more frequently shortly after commencing
treatment in patients with a deficiency of protein C.
Protein C is an innate anticoagulant that, like the
procoagulant factors that warfarin inhibits, requires
vitamin K-dependent carboxylation for its activity. Since
warfarin initially decreases protein C levels faster than
the coagulation factors, it can paradoxically increase the
blood's tendency to coagulate when treatment is first
begun , leading to massive thrombosis with skin
necrosis and gangrene of limbs. Its natural counterpart,
purpura fulminans, occurs in children who are
homozygous for certain protein C mutations
37.
38. Osteoporosis
๏ After initial reports that warfarin could reduce bone
mineral density, several studies have demonstrated a
link between warfarin use and osteoporosis-related
fracture. A 1999 study in 572 women taking warfarin for
deep venous thrombosis, risk of vertebral fracture and
rib fracture was increased; other fracture types did not
occur more commonly] A 2002 study looking at a
randomly selected selection of 1523 patients with
osteoporotic fracture found no increased exposure to
anticoagulants compared to controls, and neither did
stratification of the duration of anticoagulation reveal a
trend towards fracture.
39.
40. Purple toe syndrome
๏ Another rare complication that may occur early during
warfarin treatment (usually within 3 to 8 weeks of
commencement) is purple toe syndrome.This condition
is thought to result from small deposits of cholesterol
breaking loose and causing embolisms in blood vessels
in the skin of the feet, which causes a blueish purple
colour and may be painful.
๏ It is typically thought to affect the big toe, but it affects
other parts of the feet as well, including the bottom of
the foot (plantar surface). The occurrence of purple toe
syndrome may require discontinuation of warfarin.
41.
42. Drug interaction
๏ Warfarin interacts with many commonly used drugs,
and the metabolism of warfarin varies greatly between
patients.Some foods have also been reported to
interact with warfarin.
๏ When taken with nonsteroidal anti-inflammatory drugs
(NSAIDs), warfarin increases the risk for gastrointestinal
bleeding. This increased risk is due to the anti-platelet
effect of NSAIDs as well as the possible damage to the
gastrointestinal mucosa
43. ๏ Many commonly used antibiotics, such as
metronidazole or the macrolides, will greatly increase
the effect of warfarin by reducing the metabolismof
warfarin in the body.
๏ Thyroid activity also appears to influence warfarin
dosing requirements;hypothyroidism (decreased
thyroid function) makes people less responsive to
warfarin treatment,while hyperthyroidism(overactive
thyroid) boosts the anticoagulant effect. Several
mechanisms have been proposed for this effect,
including changes in the rate of breakdown of clotting
factors and changes in the metabolism of warfarin
44. Contraindications
๏ Warfarin is contraindicated in pregnancy, as it passes
through the placental barrier and may cause bleeding in
the fetus; warfarin use during pregnancy is commonly
associated with spontaneous abortion, stillbirth,
neonatal death, and preterm birth. Coumarins (such as
warfarin) are also teratogens, that is, they cause birth
defects
45. Reference
๏ Essential Of Medical Pharmacology โK.D. Tripathi 7
edition
๏ Essential Of Pharmacotherapeutics โ F.S.K. Barar 4
edition
๏ https://www.rxlist.com/heparin-drug.htm#interactions
๏ https://www.rxlist.com/search/rxl/coumadin