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28 Cards in this Set
- Front
- Back
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What is haemostasis?
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the arrest of blood loss from damaged blood vessels.
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What are the two main broad main steps in haemostasis?
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1) the adhesion and activation of platelets 2) activation of clotting factors, leading to blood coagulation (fibrin formation)
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What is Thrombosis?
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a pathological condition. haemostatic plug formation associated with arterial disease or stasis of blood in veins and atria of the heart.
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What is an embolus? What determines where they end up?
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A portion of a thrombus that breaks away, if a venous thrombus it can end up in the lungs, if from the left heart it can end up in the brain/other organ.
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Give a procoagulant drug, mechanism, effect, and pharmacokinetic aspects.
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eg: Vit K (synthetic water soluble-menadiol) vit K dependent: II VII IX X factors
Mechanism: When reduced acts as a cofactor in gama-carboxylation of glutamic acid Administration: oral, i.v., i.m. Metabolised: in liver and excreated in bile and urine |
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Give two examples of Injectable anticoagulanys?
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Heparin and low-molecular-weight heparins.
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Who do heparin and low-molecular weight heparins work?
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accelerates the action of antithrombin III which inactivates factors XIIa, IXa, Xa, IIa.
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What are the Vit K dependent factors?
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II, VII, IX, X
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Give an example of a LMWH?
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dalteparin
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How is heparin administered and how is it eliminated?
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i.v. (immediate action) s.c. (acts in an hour). Two phase elimination: first fast then slow.
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How are the effects of heparin measured?
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activated partial thromboplastin time
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how are LMWH give and eliminated and why are they used more than heparin?
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s.c. with a longer half life than heparin, blood monitoring not required. Eliminated by the kidney.
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What are the unwanted effects of heparins and LMWHs?
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Bleeding, Osteoporosis (with long term use), Thrombosis associated with thrombocytopenia
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How can the unwanted effects of heparin and LMWH be treated?
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Protamine sulfate for bleeding (basic-netrolisises heparin) Danaparoid for which is used for thrombocytopenia.
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Give an example of an oral anticoagulant?
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Warfarin
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Give the mechanism of Warfarin?
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inhibits of reduction of Vit K in the gama-carboxylation of Glu in factors II, VII, IX, X.
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How is warfarin given?
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Oral, small distribution volume, and effects take days as factors have to degraded.
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How are Warfarins effects measured?
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Prothrombin time
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How is Warfarin metabolised?
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In the liver
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What are the effects of Warfarin?
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Bleeding (bowle or brain)
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How are the unwanted effects of warfarin treated?
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Vit K, fresh plasma/coagulation factors.
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What are the drug interactions of warfarin?
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Increased risk of bleeding (aspirin, ciprofloxacin) or lessen anticoagulant action (carbamazepine)
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What are the effects of Aspirin?
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irreversible inhibits cyclo-oxgenase- altering the balance between thromboxane A2 (promotes platelet adhesion and aggregation) and PG-I2 which inhibits it. Unlike vascular endothelium platelets can't synthesis more enzyme os TXA2 only restored when new platelets are formed.
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Give two antiplatelet agents?
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Aspirin and a platelet aggregation inhibitor: GPIIb/IIIa receptor antagonist: abciximab.
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Explain the actions of abciximab? How is it given?
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Blockes fibrinogen linking platelets with antibody Fab. i.v. infusion.
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Fibrinolytic drugs...what the fuck is going on here then?
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Example: streptokinase. increases the conversion of plasminogen into plasmin. Main unwanted effect is bleeding.
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What are the prophylactic uses of aspirin?
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uses to reduce risk of occlusive cardiovascular disease in patients with MI of unstable angina.
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What drugs would you pick for short term/long term treatment
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Heparin and LMWH for short term and warfarin for long term.
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