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Flashcards in NOACS Deck (19)
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1
Q

How are NOACs excreted?

A

Renally
Rivaroxaban is METABOLISED by the liver though, so moderate to severe impairment may incrase levels

Cutoff is less than 25 cr cl for apixaban and 30 ml/min for the others.

2
Q

MOA Dabigatran

A

Direct thrombin inhibition

3
Q

t1/2 Dabigatran

A

12-17 hours

4
Q

Which NAOC do you have to be careful of CYP 3A4 inducers/inhibitors?

A

Rivaroxaban

5
Q

For which NOAC are p glycoprotein inhibitors (eg verapamil) particuarly relevant?

A

Dabigatran

6
Q

Can you give the NOACs in pregnancy and breastfeeding?

A

No

7
Q

Dabigatran: most sensitive test for determining if present

A

Thrombin time

  • Normal TT will exclude presence
  • Normal APTT suggests unlikely that a high level is contributing to bleeding

No Chromogenic Xa assay
Can check the dilute thrombin clotting time assay - prolonged in confirmatory test

If APTT prolonged, exclude heparin and low fibrinogen

8
Q

Rivaroxaban: most sensitive coagulation assay

A

PT- normal suggests not high but does not exclude presence
APTT and PT cannot estimate intensity of anticoagulant effect
Does NOT prolong TT
APTT is prolonged dose dependently but is less sensitive than PT

Specific anti-factor Xa chromogenic assay for quantitative measurement - not the regular anti Xa assay

If PT prolonged, exclude warfarin and liver disease

9
Q

Apixaban: most sensitive coagulation assay

A

Need anti-factor Xa chromogenic assay to estimate accurately
Normal PT and APTT does NOT rule out significant anticoagulant effect- but unlikely if PT is normal

10
Q

How long should you stop the NOAC before an epidural goes in? After it goes in?

A

24 hours for all three
After it is in, don’t give dabigatran at all. 22-26 hours for rivarox and 26-30 hours for apixaban
After removal, wait 6 hours for all three before next dose.

11
Q

Dialysis works for…

A

Speed up elimination with dabigatran only

12
Q

If there is need for urgent surgery and still therapeutic effect, what experimental treatment could be discussed with haem?

A

activated prothrombin complex concentrate , prothrombinex, tranexamic acid
Restrict use to when supportive measures alone will not be enough

Note if normal PT or APTT for the relevent drug, unlikely to help if given pro haemostatic agents.

13
Q

How would you convert to heparin from a noac?

A

Rivarox/apix:Wait one half life after last dose then dont use loading dose of heparin

Dabig: 12-24 hours where crcl over 30
wait 48 hours if less than 30 (remember LMWH not recommended if Cr Cl under 30)

14
Q

how do you switch from warfarin?

A

When INR is 2.5 or less, then start NOAC the next day

15
Q

How do you switch TO warfarin?

A

a few days after starting warfarin, stop NOAC- depends on renal function as this will influence warfarin onset Stop NOAC when INR over 2 for 2 days

16
Q

Should activated charcoal be considered?

A

If within 2 hours of last dose

17
Q

Rivaroxaban trial for AF?

A

ROCKET-AF

  • Rivarox vs Warfarin in non valvular AF
  • Noninferior to warfarin for stroke and bleeding risk
  • Less ICH and fatal bleeding
  • No difference in rates for major bleeding
18
Q

Apixaban AF trial?

A

ARISTOTLE

  • Apix vs warfarin
  • Nonvalvular AF, no DAPT patients
  • Improved mortality, bleeding, stroke rates
19
Q

DABIGATRAN AF trial?

A

RELY
150mg- Dabig less stroke than warfarin, similar bleeding risk
110mg lower major bleeding, similar stroke, embolism
Both reduced ICH, increased GI bleeding and common dyspepsia