drugs for coagulation disorders Flashcards
what is hemostasis
this is the injury to small vessels
¡ Platelets bind with high affinity to the damaged vessel. Activated platelets release adenosine diphosphate (ADP) and thromboxane A2 which stimulate the activation of new platelets, platelet aggregation and vasoconstriction.
hemostasis
how do we fix broken small blood vessels
¡ Platelets bind with high affinity to the damaged vessel. Activated platelets release adenosine diphosphate (ADP) and thromboxane A2 which stimulate the activation of new platelets, platelet aggregation and vasoconstriction.
when is the extrinsic pathway activated - what is released from the damaged cells
when outside of the blood vessel, triggered when tissue thromboplastin is released from damaged cells
what is release when the outside of a blood vessel is damaged
tissue thromboplastin is released
what pathway catalyzes the formation of factor Xa
extrinsic pathway
when is the intrinsic pathway triggered
it is triggered when collagen is exposed at the site of vascular injury
what does the common pathway do
synthesis of factor xa
how is clot dissolved
tissue plasminogen activator converts plasminogen to plasmin, dissolving the clot
what is the dissolving of a clot called
firbinolysis
what works to destroy a clot
plasmin
what converts plasminogen to plasmin
tissue plasminogen factor
thromboembolic disorders (3)
formation of non-therapeutic clots
occulsion of srterial vessels
embolus
what leads to MI and CVA
occulsion of arterial vessels
embolus occurs when
a piece of stable thrombi breaks off and lodges in smaller blood vessels
anticoagulant drugs wokr to modulate what and the formation of what
modulate coagulation cascade and thrombin formation
what work to lengthen clotting times and prevent thrombi from forming in the veins
anticoagulant drugs
should you give anticoagulant drugs in cases of MI or CVA
yes, through iv or subcutaneous
heparin catalyzes what
catalyzes the inactivation of thrombin
what enhances the ability of antithrombin III to inactivate thrombin and clotting factor Xa
heparin
when thrombin is inactivated what happens
no fibrin = no clotting
what is heparin used for the prevention of what
used for the prevention of venous throbosis, PE, DIC, MI and stroke
what should you monitor when having a patient on heparine
for bleeding
low molecular weight heparins focus more on what
same as heparin, more focus on factor Xa
what is the drug class of choice for prevention of DVT
low molecular weight heparins
warfarin - blocks the synthesis of what clotting factors
block the synthesis of clotting factors thrombin, VIIa, IXa, Xa
what does warfarin inhibit
epoxide reductase
what does decreased vitamin K inhibit
inhibits the production of active coagulation factors
when transitioning from heparin to warfarin therpay, why must drugs be co administered for three days
because of the increased risk for bleeding and the anticoagulant affect lasts 4-5daus
what should patients avoid when on warfarin
vitamin k rich foods
why must patients avoid vitamin k foods when on heparin
because it reduced the effectiveness of the drug
direct acting thrombin inhibitors
directly binds to and inhibits thrombin
what is approved to reduce the risk of stroke and systemic embolism in clients with atrial fibrillation, DVT and PE
direct acting thrombin inhibitors
direct acting factor Xa inhibitors inhibit what pathways, and reduce the development of
inhibits the intrinsic and extrinsic pathways of the coagulation cascade - reducing thrombin formation and development of thrombi
inhibits the intrinsic and extrinsic pathways of the coagulation cascade - reducing thrombin formation and development of thrombi
direct acting factor Xa inhibitors
what are used for the prevention and treatment of deep vein thrombosis
direct acting factor Xa inhibtiors
what reduces the risk of pulmonary emboli in pt undergoing knee or hip surgery
direct acting factor Xa
what are more predicatble and require less monitoring, warfarin or direct acting thrombin and factor xa inhibitors
direct acting thrombin and factor Xa inhibitors
what is contraindictaed in pregnacy and in lactation
warfarin
common adverse effects of anticoagulant drugs
bleeding
antiplatelet drugs
inhibit platelet aggregation
irreversible cycooxygenase inhibitors - aspirin - inhibits the activity and synthesis of what
block the activity of COX1 and COX2, inhibiting the synthesis of prostaglandins - no prostaglandins means no thrombin
adenosine diphosphate receptor antagonists
irreversibly change the molecular conformation of ADP receptors, so the platelets no longer release the chemical signal, so they cannot form a clot
irreversibly change the molecular conformation of ADP receptors, so the platelets no longer release the chemical signal, so they cannot form a clot
ADP receptor antagonists
glycoprotien IIb/IIIa receptor antagonists- prevent what?
prevents platelet aggregation and thrombus formation, the glycoprotien IIb/iiia are involved in platelet aggregation
glycoprotien IIb/IIIa antagonists are reserved for people with waht
stroke or MI
thrombolytic drugs promote what
promote firbinolysis by converting plasminogen into plasmin
when are thrombolytic drugs contraindicated
with any trauma and bleeding disorders
what should you monitor for with thrombolytic drugs
cerebral hemorrhage
how can the effects be reversed for thrombolytic drugs
aminocapronic acid
what is aminocapronic acid
this is an enzyme inhibtior that inactivates plasmin
antifibrinolytic drugs
used to facilitate blood clotting and shorten bleeding time
what prevents the dissolution of fibrin
antifibrinolytic drugs
when are antifibrinolytic drugs used
post surgery to reduce bleeding at surgical sites
what should you assess for when giving antifibrinolytic drugs
assess for excessve clotting
