24 - Antithrombotic Therapy Flashcards

1
Q

what factors does unfractionated heparin inhibit?

A

Xa and IIa

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2
Q

what factor do low MW heparin and fondaparinux inhibit?

A

Xa

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3
Q

what can be given to “undo” heparin?

A

protamine

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4
Q

does LMW heparin need monitoring?

A

no - only unfractionated does

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5
Q

side effects of heparin

A

bleeding
osteopenia / bone loss
heparin induced thrombocytopenia (HIT)

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6
Q

mechanism for HIT

A

heparin binds platelet factor 4 > IgG produced against this complex > aggregation and removal from ciruclation

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7
Q

fondaparinux

A

synthetic heparin like molecule that only inhibits F.Xa and has less side effects

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8
Q

key to tx of HIT

A

stop ALL heparin (even catheters and stuff coated with it) and treat w/ alternative anti coag and avoid platelet transfusions

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9
Q

warfarin mechanism

A

inhibits enzymes that regenerate reduced form of Vit K

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10
Q

why does warfarin need to be monitored so closely?

A

levels can change significantly due to lots of food/drug interactions

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11
Q

antidotes for warfarin

A

vit K, FFP

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12
Q

unique side effects of warfarin

A

embryopathy (6-12 wks GA), warfarin induced skin necrosis

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13
Q

mechanism for warfarin induced skin necrosis

A

since warfarin first inactivates protein C, get paradoxical pro-coagulation stage early on which causes small clots in skin vessels > necrosis. can be avoided by “bridging” them past this period on another anti coag

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14
Q

lepirudin, bivalirudin, argatroban are ___ and are primarily used for ___

A

IV direct thrombin inhibitors

HIT

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15
Q

oral direct thrombin inhibitor

A

dabigatran

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16
Q

direct anti-Xa inhibitors

A

rivaroxaban, apixaban

17
Q

clopidogrel mechanism

A

irreversibly blocks platelet ADP receptor

18
Q

prasugrel, ticagrelor, dipyridamole are all ___

A

antiplatelet agents

19
Q

indications for thrombolytic therapy

A

acute ischemic stroke w/in 3 (4.5) hrs of sx onset
pulm embolism w/ hemodynamic compromise
acute MI
extensive acute DVT