anticoag/ platelets Flashcards

1
Q

which factors does unfractionated heparin block?

A

Unfractionated heparin forms a complex with antithrombin III in the inactivation of

mostly factor Xa and II
but also 9,11 and 12

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2
Q

which enzyme does warfarin inhibit?

A

epoxide reductase

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3
Q

when is warfarin pro-thombotic?

A

initially - often covered with LMWH
in those with mild-moderate hepatic function

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4
Q

what is the mechanism of apixaban , rivaroxaban and dabigatran ?

A

Rivaroxaban and apixaban are factor Xa inhibitors
whereas dabigatran is a direct thrombin (factor IIa) inhibitor.

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5
Q

what is Andexanet alfa?

A

recombinant modified human factor Xa (FXa) protein used as a specific reversal of rivaroxaban and apixaban

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6
Q

when is aspirin given based on QRISK score?

A

anyone with QRISK >20% (10 year CVS risk score)

or specific patients 10-20% e.g. diabetics

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7
Q

what are rules of clopidogrel after drug elluting stent and bare metal stent

A

BMS - 1 month
DES - 6 months

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8
Q

which commonly used drug should be avoided with clopidogrel?

A

omeprazole

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9
Q

which patient group should you avoid prasugrel in?

A

> 75 yrs
<60kg

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10
Q

which antibiotics/fungal/virals should be avoided in ticagrelor?

A

clarithromycin
ketonazole

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11
Q

how many days pre-op should clopidogrel be stopped?

A

7 days

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12
Q

how many days should the following be stopped for neuroaxial blocks?

A

tirofiban - hrs
clopi - 7 days
ticagrelor - 5 days
abciximab - 2 days
aspirin - continue

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13
Q

what is gold standard for assessing platelet function?

A

Optical light aggregometry

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14
Q

what binds GP IIb/IIIa?

A

fibrinogen, wVF

Tirofiban, abciximab

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15
Q

for an epidural, when can this be performed after the last LMWH dose?

A

12 hours

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15
Q

what is the life time of a platelet?

A

8-12 days

16
Q

what is mechanism of fondaparinux ? what is the dose and route of administration?

A

indirect anti Xa
given s/c
2.5mg

Dalteparin and fondaparinux both bind ATIII and enhance its action. Fondaparinux only does this for Xa and dalteparin for Xa and IIa