unit 7.1 Coag modifi chapter 27 coagulation modifier

Term Definition
anticoagulants substances that prevent or delay coagulation of theblood
anitfibrinolytic drugs drugs that prevent the lysis of fibrin and in doing so promote clot formation
antiplateley drugs substances that prevent platelet plugs from formin
antithrombocin III (AT-III) a substance that inactivates three major activating factors of the clotting cascade: activated II (thrombin), activated factor X, and IX
clot insoluble solid elements of blood that have chemically separated from the liquid plasma component of the blood
coagulation the process of blood clotting; more specifically the sequential process by which the multiple coagulation factors of the blood interact
coagulation cascade the serios of steps beginning with the intrinsic or extrinsic pathways of coagulation and proceeding through the formation of a fibrin clot
Deep vein thrombosis (DVT) the formation of a thrombus in one of the deep veins of the body; most commonly occurs in the iliac and femoral veins
emobolus a blood clot (thrombus) that has been dislodged from the wall of a blood vessel and travels through the bloodstream
enzyme protein molecule that catalyzes chemical reactions of other substances without being altered or destroyed in the process
fibrin specificity property of thrombolytic drugs of activation the conversion of plasminogen to plasmin only in the presence of established clots having fibrin threads
fibrinogen a plasma protein that is converted into fibrin by thrombin in the presence of calcium ions
fibrinolysis process of fibrin decomposition produced by the actions of the enzymatic protein fibrinolysis
fibrinolytic system an area of the circulatory system undergoing fibrinolyss
hemophilia rare inherited blood disorder in which the blood does not clot normally
hemorheological drugs drugs that alter the function of platelet without compromising their blood clotting properties
hemostasis the arrest of bleeding either by the physiological properties of vasoconstriction and coagulation or by mechanical, surgical, or pharm means
hemostatic referring to any procedure, device, or substance that arrests the flow of blood
plasmin the enzymatic protein that breaks down fibrin into fibrin degradation products derived from plasminogen
plasminogen a plasma protein that is converted to plasmin
pulmonary embolus (PE) blockage of a pulmonary artery by foreign matter such as fat, air, timeout, cells, or a thrombus that has typically arisen from peripheral vein
stroke occlusions of the blood vessels of the brain by an embolus thrombus, or cerebrovascular hemorrhage resulting in ischemia to brain tissue
thromboembolic events events in which a blood vessel is blocked by an embolus carried in the blood stream from site of formation.
thrombolytic drugs drugs that dissolve thrombi by functioning similarly to tissue plasminogen activator
thrombus blood clot; an aggregation of platelets, fibrin, clothing factors, and cellular elements of the blood that is attached to the interior wall of a vein or artery
tissue plasminogen activator a naturally occurring plasminogen activator secreted by vascular endothelial cells in the walls of the blood vessels
substances that promote coagulation platelets, von willebrand factor, activated clotting factors, and tissue thromboplastin
substances that inhibit coagulation prostacyclin, antithrombin III, proteins C and S
when blood vessels are damaged by penetration from the outside _____is released thromboplastin-a substance contained in the walls of blood vessels
the extrinsic pathway is activated when factor XII comes into contact with exposed collage on the inside of damaged blood vessles
Antiplatelet drugs beneficial in preventing heart attacks and strokes
thrombolytic drugs lyse clots or thrombi that have already formed
Antifibrinolytic drugs also known as hemostatic drugs promote blood coagulation and are helpful in management of conditions in which excessive bleeding would be harmful
anticoagulants have no direct effect on a blood clot that has already formed
heparin (anticoagulant) binds to antithrombin III (AT-III) which turns off three main activating factors; activated factor II, activated factor X, and IX
thrombin is the most sensitive to the actions of heparin
AT-III is the major natural inhibitor of thrombin in the blood
low molecular weight heparins (LMWHs) are synthetic and have smaller molecular structure
LMWH drugs enoxaparin (Lovenox), dalteparin (Fragmin), nodroparin calcium (Flaxiparine), tinzaparin sodium (Innohep)
heparin binds to factors II, X, and IX
LMWHs activated for factor II
warfarin (Coumadin ) inhibits clotting factor synthesis.
warfarin (Coumadin) works by inhibiting vitamin K synthesis by bacteria in the GI tract. This action inhibits production of clotting factors
vitamin K dependent clotting factors II, VII, IX, and X (synthesized in the liver)
indications for anticoagulants MI, instable angina, trial fibrillation, presence of indwelling devices such as mechanical heart valv
warfarin contraindicated in pregnancy
LMWH's are contraindication in patients with an indewelling epidural catheter
anti platelet drugs work to prevent platelet adhesion at the site of blood vessel injury which occurs before the clotting cascade
when a blood vessel is injured (either by tram, rupture of plaque..) fibronextin and collage present in the walls becomes exposed collagen in a potent stimulator of platelet adhesion
hemostatic function of ADP, serotonin, and platelet factor IV are they function as platelet recruiters, and they are potent vasoconstrictors
many antiplatelet drugs work by affecting the ________ pathway cyclooxygenase
cyclooxyrgenase pathway is one of the common final enzymatic pathways in the arachidonic acid pathway that operates within platelets and on blood vessel walls
Aspirin inhibits cyclooxyrgenase in the platelet irrecersibly so that the platelet cannot regenerate this enzyme for the lifespan of a platelet (7 days)
inhibition of cycloxygenase within a platelet prevents formation of TXA2 a substance that causes blood vessels to constrict and platelets to aggregate = dilation of blood vessels and prevention of aggregat
Dyprymidamole – another antiplateled drugs inhibits platelet aggregation by preventing release of ADP, platelet factor IV and TXA2
Clopidogrel is a anti platelet drug called ADP inhibitor it works by altering the platelet membrane os that it can no longer receive the signal to aggregate and form a clot
combination of Aspirin and clopidogrel has been shown to be effective in patients with known cardiovascular disease, but not in patients who have only risk factors
common indicators for dual anti platelet therapy include post angioplasty and placement of a stent and 1 year post MI
Aspirin is indicated for stroke prevention
Clopidogrel is also used for reducing the risk of fatal and nonfatal thrombotic stroke and is used for prophylaxis against transient ischemic attacks (TIA) as well as post MI
contraindications for anti platelet drugs include thrombocytopenia, active bleeding, leukaemia, traumatic injury, GI ulcer, vitamin K deficiency and recent stroke
ADE for antiplatele drugs can be serious, and can induce serious bleeding episode
thrombolytic drugs are coagulation modifiers that lyse thrombin in the coronary arteries, which re-establishes good flow to blood stared heart muscle
streptokinase (SK) is a substance that breaks down clots
fibrinolytic system m is responsible for dissolving clots
fibrinolytic system breaks down the thrombus in the blood vessel quickly so that the delivery of blood to the heart muscle via the coronary arteries is re-established
thrombolytics dissolve clots by activating the conversion of plasminogen to plasmin, which breaks down or lyses the thrombis
t-PA is a naturally occurring plasminogen activator secreted by vascular endothelial cells
indication for use of thrombolytic therapy thrombus on either the arterial side of the circulation – acute MI, arterial thrombosis, DVT, occlusion of shunts or catheters, pulmonary embolism
exception for use of thrombolytic therapy is for a cloth that has formed in the blood vessels that are connected directly to the CNS
ADE for thrombolytic therapy are internal, intracranial, and superficial bleeding , hypersensitivity, anaphylactoid reactions, nausea, vomiting, and hypotension
antifibrinolytic drugs all (also called hemostatic drugs) prevent the lysis of fibrin and promote clot formation
fibrin helps make a platelet plug insoluble and anchors the clot to the damaged blood vessel
two synthetic antifibrinolytics tranexamic acid, and desmopressin
natural antifibrinolytic aprotinin
there are also topical antifibrinolytic drugs that stop excessive bleeding thrombin, muvrofibrillar collagen, absorbable gelatin, and oxidized cellulose
antifibrinlyitics are useful in both prevention and treatment of excessive bleeding resulting from systemic hyperfibrinolysis of surgical complications
ADE of antibrinolytics are infrequent and mild, however can cause thrombotic events such as cerebrovascular thrombosis and acute MI
adntifibrinolytics interactions drugs such as estrogens or oral contraceptives used concurrently with tranexamic acid or aprotinin, may cause additive effects

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